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How to pass commands to gdb from python
Question: I have launched GDB using subprocess.call methond in python .Can any one help
how to pass commands to gdb (like 'info threads') from python script.
Answer: It is better to use [Pexpect](https://pexpect.readthedocs.org/en/latest/)
module if you want to interact with interactive shells.
But I suggest you to use Python bindings that shipped with gdb.
infothreads.py:
import gdb
gdb.execute('info threads')
gdb.execute('continue')
Run it using `-x` option of gdb:
gdb -x infothreads.py -p 21686
Documentation on Python bindings may be found here: [Python
API](https://sourceware.org/gdb/onlinedocs/gdb/Python-API.html#Python-API)
|
Parse arbitary date formats in Python (including rfc3164)
Question: PHP has the amazing [strtotime()](http://php.net/strtotime) function which
takes pretty much anything and turns it into a time.
I'm looking for something similar in Python?
As an example of why: I'm parsing syslogs which have the dumbest format ever
(aka [rfc3164](http://www.ietf.org/rfc/rfc3164.txt)) which omits a year and
includes a space-padded day-of-month.
Currently in Python I'm doing this:
import datetime
d='Mar 5 09:10:11' # as an example
# first remove the space, if it exists
if d[4] == ' ':
d = d[0:4] + d[5:]
# append this year (I know, it could be last year around Dec/Jan!)
d = str(datetime.datetime.now().year) + ' ' + d
# now we can feed it strptime
date = datetime.strptime(d, "%Y %b %d %H:%M:%S")
This is really ugly.
Is there a better way?
Answer: I think you are looking for the [`dateutils`](http://labix.org/python-
dateutil#head-c0e81a473b647dfa787dc11e8c69557ec2c3ecd2) module:
In [12]: d = 'Mar 5 09:10:11'
In [13]: import dateutil
In [14]: dateutil.parser.parse(d)
Out[14]: datetime.datetime(2015, 3, 5, 9, 10, 11)
|
Can voluptuous code pass pylint?
Question: I run `pylint -E` as part of the tests on my Python project to ensure that
errors don't creep into untested code. Generally this works quite well. But
recently I've been running into problems with
[voluptuous](https://pypi.python.org/pypi/voluptuous) and pylint.
The problem is that pylint thinks that the values returned by voluptuous
Schemas are lists, which is simply not the case. Here's a toy program:
import voluptuous
MyType = voluptuous.Schema({
'q': str
})
def foo(bar):
bar = MyType(bar)
q = bar.get('q')
print q
foo({'q': '1324'})
It runs just fine:
$ python toy.py
1234
pylint, however, flags the `.get()` call:
$ pylint -E toy.py
No config file found, using default configuration
************* Module toy
E: 11, 8: Instance of 'list' has no 'get' member (no-member)
How can I get this program to pass `pylint -E`?
Answer: One option is to ignore the `voluptuous` module entirely, e.g.
$ pylint -E --ignored-modules=voluptuous toy.py
(passes)
If would be nice if `pylint` understood `voluptuous` better, though.
|
Python scatter - change marker style based on entity
Question: I'm struggling for days trying to resolve this problem: I have cartesian
coordinates on the y-axis (for depth from 0 to 1) and numbers with different
values on the x axis (the numbers are the firing rate of different cells
populations at the given depth on y axis, so they vary randomly). I would like
to show bigger size of markers in the scatterplot corresponding to a bigger
x-axis value (firing rate). Thank you for any suggestion. This is the code
(not working).
import matplotlib.pyplot as plt
import numpy as np
import matplotlib.cbook as cbook
x = np.genfromtxt('x_dex.csv', delimiter=',')
y = np.genfromtxt('z_dex.csv', delimiter=',')
array = [i for i in x if i > 4]
array.sort()
s = [30*2**n for n in range(len(array))];
plt.subplot(212)
plt.scatter(x,y,s=s)
plt.show()
This is unfortunately not showing the correct relation between size of marker
and depth.
Answer: The line where you compute your 'size' values looks incorrect to me:
s = [30*2**n for n in range(len(array))];
This will give you a list containing:
s = [30*2**0, 30*2**1, 30*2**2, ..., 30*2**(len(array) - 1)]
The values bear no relation to `y`, so I assume this is not what you intended.
Maybe you meant something more like this:
s = 30 * 2 ** y
* * *
There are actually several other issues here:
* Don't give your variables names like `array` \- this can lead to confusion with `numpy.array`. It's even worse in this case, since `array` is actually not an array but a Python `list`!
* Since you're dealing with numpy arrays, it's much faster to use vectorization rather than list comprehensions. For example, you could use:
array = x[x > 4]
rather than
array = [i for i in x if i > 4]
* After your list comprehension `array = [i for i in x if i > 4]`, `array` will have a different number of elements to `y` if there are elements in `array` that are less than 4.
* `array.sort()` will sort the list _in place_ , which means that the order of the elements in `array` will no longer match the order of elements in `y`.
* In fact, sorting seems rather pointless in this situation - since you're making a scatter plot the order of the points should not matter.
* You're not writing MATLAB code any more, so there's no need to end lines on a semicolon (although it won't do any harm if you do).
* * *
Here's my educated guess at what you're trying to do:
import matplotlib.pyplot as plt
import numpy as np
x = np.genfromtxt('x_dex.csv', delimiter=',')
y = np.genfromtxt('z_dex.csv', delimiter=',')
# get the set of indices that will sort x in ascending order, apply these
# to both x & y
order = np.argsort(x)
x_sorted = x[order]
y_sorted = y[order]
# keep only xy pairs where x > 4
valid = x_sorted > 4
x_valid = x_sorted[valid]
y_valid = y_sorted[valid]
# compute the sizes
s = 30 * 2 ** y_valid
# plot
plt.subplot(212)
plt.scatter(x_valid, y_valid, s=s)
plt.show()
|
Python failing to import module from script
Question: If I start python and input `import tables` it works fine but when I run
`python m_BlackrockLib.py` (which has `import os, struct, tables, pickle, re,
shutil` as it's first line) I get the error `ImportError: No module named
tables`. I can see that tables is present in
`/usr/local/anaconda/lib/python2.7/site-package` so I'm not sure what is
causing this error. Can anyone see the issue?
Answer: I needed to add `import conda` to the script above the other imports because I
have `tables` installed in anaconda
|
How to map structured data to schemaRDD in Spark?
Question: I've asked this question differently before but there are some changes so I
thought asking it again as a new question. I have a structured data which only
part of it is in json format but I need to map the entire data to an
schemaRDD. The data looks like this:
> 03052015 04:13:20
> {"recordType":"NEW","data":{"keycol":"val1","col2":"val2","col3":"val3"}
Each line starts with date followed by time and a json formatted text. I need
to map not only the text in json but also the date and time into the same
structure.
I tried it in Python but obviously it doesn't work because Row does not take
an RDD (jsonRDD in this case).
from pyspark.sql import SQLContext, Row
sqlContext = SQLContext(sc)
orderFile = sc.textFile(myfile)
orderLine = orderFile.map(lambda line: line.split(" ", 2))
anotherOrderLine = orderLine.map(lambda p: Row(date=p[0], time=p[1], content=sqlContext.jsonRDD(p[3])))
schemaOrder = sqlContext.inferSchema(anotherOrderLine)
schemaOrder.printSchema()
for x in schemaOrder.collect():
print x
The goal is to be able to run a query like this against the schemaRDD:
select date, time, data.keycol, data.val1, data.val2, data.val3 from myOrder
How can I map the entire line to a schemaRDD?
Any help is appreciated?
Answer: The sqlContext.jsonRDD creates a schema rdd from an RDD containing strings
where each string contains a JSON representation. This code sample is from the
SparkSQL documentation (<https://spark.apache.org/docs/1.2.0/sql-programming-
guide.html>):
val anotherPeopleRDD = sc.parallelize("""{"name":"Yin","address":{"city":"Columbus","state":"Ohio"}}""" :: Nil)
val anotherPeople = sqlContext.jsonRDD(anotherPeopleRDD)
One of the cool things about jsonRDD is the fact that you can provide and
additional parameter stating the JSONs schema, which should improve
performance your performance. This can be don by creating an schemaRDD (just
load a sample document) and then call the schemaRDD.schema method to get the
schema.
|
How to copy text file in python
Question: Here's what I want to do:
import copy
def printtext(swefile):
for row in swefile:
print(row)
text = open("wordsv.txt","r",encoding="utf-8")
text2 = copy.copy(text)
printtext(text)
print(text2.readlines())
But it is not possible, TypeError: cannot serialize '_io.TextIOWrapper'
object. So I wonder if there is a good method for "cloning" the text variable,
so that I could print all the lines again. I know that I could just read the
file again, but that answer does not solve the bigger problem I have so any
suggestion on how to get this done is helpful.
* * *
Here's the larger context as I haven't been able to solve my problem with your
suggestions:
with open(textfilename, "r", encoding = "utf-8") as swefile:
for row in swefile:
word = row.strip()
tempfile = copy.copy(swefile)
l = getFurthest(word,tempfile)
The thing that I want to happen here is that i want to send the portion of
`swefile` that has not been read yet (i.e. iterated over yet by the for loop)
to `getFurthest()`! And I can't send `swefile` because that will make the
whole thing read so the iterations in the for loop will stop, right? So how
can I send only the portion of the textfile that has been read to
`getFurthest()` while still being able to iterate over the rest of it after?
Answer: If you're trying to avoid re-opening the file, but want to read it twice, you
can use [`seek()`](https://docs.python.org/3/library/io.html#io.IOBase.seek):
import copy
def printtext(swefile):
for row in swefile:
print(row)
text = open("wordsv.txt","r",encoding='utf-8')
printtext(text)
text.seek(0)
printtext(text)
If you just care about the text, you can do this:
import copy
def printtext(swefile):
for row in swefile:
print(row)
text = open("wordsv.txt","r",encoding='utf-8').readlines()
text2 = copy.copy(text)
printtext(text)
printtext(text2)
Here `text` is a list of the lines in `wordsv.txt`, and you then copy the list
into text2 (i.e. changing `text` won't change `text2`).
|
wxPython -- BoxSizers not placing things correctly
Question: I can't figure out what I'm doing wrong. I just made the jump from Tkinter to
wxPython and I'm trying to figure out BoxSizers. I'd look this question up,
but I don't even know what to look up. This panel is filling the space of a
Frame, it's supposed to show a line of text with a progressbar underneath it
and that's all supposed to take up the bottom 1/5 of the panel or so, centered
horizontally (eventually I'm going to add a background image behind it). But
what happens is I only see the text and only about 40% down from the top,
aligned to the left edge of the window. Here's the code:
class KhPanel(wx.Panel):
def __init__(self, parent, configSet, selectWindow):
wx.Panel.__init__(self, parent=parent)
self.frame = parent
self.configSet = configSet
whichWindow = getattr(self, selectWindow)
whichWindow()
def configWindow(self):
gaugeWidth = (1/5)*self.configSet["width"]
gaugeHeight = (1/10)*self.configSet["height"]
gaugeMax = 100
topBuffer = (8/10)*self.configSet["height"]
itemSep = (1/16)*self.configSet["height"]
vSizer = wx.BoxSizer(wx.VERTICAL)
textSizer = wx.BoxSizer(wx.HORIZONTAL)
progressSizer = wx.BoxSizer(wx.HORIZONTAL)
configText = wx.StaticText(self, label="STUFF", style=wx.ALIGN_CENTER)
configProgressBar = wx.Gauge(self, range=gaugeMax, size=(gaugeWidth, gaugeHeight))
textSizer.Add(configText, 1, wx.ALIGN_CENTER, 0)
progressSizer.Add(configProgressBar, 1, wx.ALIGN_CENTER, 1)
vSizer.Add(textSizer, 1, wx.TOP, topBuffer)
vSizer.Add(progressSizer, 1, wx.TOP, itemSep)
self.SetSizer(vSizer)
vSizer.Fit(self)
return
If you need the info, configSet.width and height are the width and height of
the parent window (currently 340 x 270). And selectWindow, in this case, is
"configWindow"
Answer: Running this code, the `gaugeWidth` and `gaugeHeight` are both getting set to
zero, which is why the progressbar is not showing. This is due to the fact
that you are doing integer math here, so 1 divided by 5 is 0. Same with 1/10.
Just change those lines to:
gaugeWidth = (1/5.0)*self.configSet["width"]
gaugeHeight = (1/10.0)*self.configSet["height"]
Then the gauge will appear. Here's some fully runnable code, slightly modified
from your unrunnable original:
import wx
class KhPanel(wx.Panel):
def __init__(self, parent, configSet):
wx.Panel.__init__(self, parent=parent)
self.frame = parent
self.configSet = configSet
self.configWindow()
def configWindow(self):
gaugeWidth = (1/5.0)*self.configSet["width"]
gaugeHeight = (1/10.0)*self.configSet["height"]
gaugeMax = 100
topBuffer = (8/10)*self.configSet["height"]
itemSep = (1/16)*self.configSet["height"]
vSizer = wx.BoxSizer(wx.VERTICAL)
textSizer = wx.BoxSizer(wx.HORIZONTAL)
progressSizer = wx.BoxSizer(wx.HORIZONTAL)
configText = wx.StaticText(self, label="STUFF", style=wx.ALIGN_CENTER)
configProgressBar = wx.Gauge(self, range=gaugeMax, size=(gaugeWidth, gaugeHeight))
textSizer.Add(configText, 1, wx.ALIGN_CENTER, 0)
progressSizer.Add(configProgressBar, 1, wx.ALIGN_CENTER, 1)
vSizer.Add(textSizer, 1, wx.TOP, topBuffer)
vSizer.Add(progressSizer, 1, wx.TOP, itemSep)
self.SetSizer(vSizer)
vSizer.Fit(self)
class MyFrame(wx.Frame):
def __init__(self):
wx.Frame.__init__(self, None, title="Test")
config = {'width':340, 'height':270}
panel = KhPanel(self, config)
self.Show()
if __name__ == "__main__":
app = wx.App()
frame = MyFrame()
app.MainLoop()
|
AttributeError: 'NoneType' object has no attribute 'shape'
Question:
import numpy as np
import cv2
from matplotlib import pyplot as plt
img = cv2.imread('AB.jpg')
mask = np.zeros(img.shape[:2] , np.uint8)
bgdModel = np.zeros((1,65), np.float64)
fgdModel = np.zeros((1,65), np.float64)
rect = (300 , 120 , 470 , 350)
#this modifies mask
cv2.grabCut(img,mask,rect,bgdModel, fgdModel , 5 , cv2.GC_INIT_WITH_RECT)
#If mask==2 or mask==1 , mask2 get 0, otherwise it gets 1 as 'uint8' type
mask2 = np.where((mask==2) | (mask==0),0,1).astype('uint8')
#adding additional dimension for rgb to the mask, by default it gets 1
#multiply with input image to get the segmented image
img_cut = img*mask2[: , : , np.newaxis]
plt.subplot(211),plt.imshow(img)
plt.title('Input Image') , plt.xticks([]),plt.yticks([])
plt.subplot(212),plt.imshow(img_cut)
plt.title('Grab cut'), plt.xticks([]),plt.yticks([])
plt.show()
on compiling I get this error :
python img.py AB.jpg
Traceback (most recent call last):
File "img.py", line 6, in <module>
mask = np.zeros(img.shape[:2] , np.uint8)
AttributeError: 'NoneType' object has no attribute 'shape'
Answer: First of all
python img.py AB.jpg
will not work as you expect (load AB.jpg from the current directory). The file
to load is hardcoded in line 6 of the provided example: to work as intended,
it should be something like this:
import sys
img = cv2.imread(sys.argv[1])
The error is returned because AB.jpg does not exist in the directory img.py is
being run from (the current working directory), and there is no verification
for a missing file before trying to read it.
|
Python 2.7 writing strings elements (character) to a binary file
Question: I am using Python 2.7 to access an API that returns JSON with a single
key="ringtone_file" and an associated value that is an mp3 file encoded for
transport via HTTP. I created a bogus mp3 file consisting of 256 bytes in
order from 0x00 through 0xff and the returned file appears below.
{"ringtone_file":"\u0000\u0001\u0002\u0003\u0004\u0005\u0006\u0007\b\t\n\u000b\f\r\u000e\u000f\u0010\u0011\u0012\u0013\u0014\u0015\u0016\u0017\u0018\u0019\u001a\u001b\u001c\u001d\u001e\u001f !\"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~ ¡¢£¤¥¦§¨©ª«¬®¯°±²³´µ¶·¸¹º»¼½¾¿ÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖ×ØÙÚÛÜÝÞßàáâãäåæçèéêëìíîïðñòóôõö÷øùúûüýþÿ"}
I accessed the API using the following code minus exception handing code
import requests
response = requests.get(url)
dict = response.json()
print dict
This yields the following output
{u'ringtone_file': u'\x00\x01\x02\x03\x04\x05\x06\x07\x08\t\n\x0b\x0c\r\x0e\x0f\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f !"#$%&\'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~\x7f\x80\x81\x82\x83\x84\x85\x86\x87\x88\x89\x8a\x8b\x8c\x8d\x8e\x8f\x90\x91\x92\x93\x94\x95\x96\x97\x98\x99\x9a\x9b\x9c\x9d\x9e\x9f\xa0\xa1\xa2\xa3\xa4\xa5\xa6\xa7\xa8\xa9\xaa\xab\xac\xad\xae\xaf\xb0\xb1\xb2\xb3\xb4\xb5\xb6\xb7\xb8\xb9\xba\xbb\xbc\xbd\xbe\xbf\xc0\xc1\xc2\xc3\xc4\xc5\xc6\xc7\xc8\xc9\xca\xcb\xcc\xcd\xce\xcf\xd0\xd1\xd2\xd3\xd4\xd5\xd6\xd7\xd8\xd9\xda\xdb\xdc\xdd\xde\xdf\xe0\xe1\xe2\xe3\xe4\xe5\xe6\xe7\xe8\xe9\xea\xeb\xec\xed\xee\xef\xf0\xf1\xf2\xf3\xf4\xf5\xf6\xf7\xf8\xf9\xfa\xfb\xfc\xfd\xfe\xff'}
What I desire to do is write each character or hex value of this string to a
file in binary format. I desire the result to be a file of size 256 bytes
where the first byte in the file has value 0 and the last byte has value 255.
I can't change the API. Can someone suggest a reasonable way of accomplishing
this with Python 2.7.
I attempted to do what was obvious to me which was to open a file for writing
in binary mode and then writing the unicode string to the file. The error
message from the codec indicates I can't write values between and including
128 and 255.
Answer: Since the string value is Unicode, you have to encode the string to write it
to a file. The `latin1` codec directly maps to the first 256 Unicode
characters, so use `.encode('latin1')` on the string.
Example:
>>> s=u'\x00\x01\x02\xfd\xfe\xff'
>>> s
u'\x00\x01\x02\xfd\xfe\xff' # Unicode string
>>> s.encode('latin1')
'\x00\x01\x02\xfd\xfe\xff' # Now a byte string.
|
How to save a list of ojects that contains a list as member to file by using pickle python?
Question: I have the following class:
class Document:
_queryID = ""
_name = []
_docId = ""
* * *
In the code I create a list called listDocuments. I fill the list with objects
of type Document.
import pickle
if __name__ == "__main__":
listDocuments = []
for i in range(0,10):
e = Document()
e._queryID = str(i)
e._docId = str(i+1)
e._name.append("h"+str(i))
listDocuments.append(e)
save_data(listDocuments, "Variations.dat")
list = load_data("Variations.dat")
for obj in listEntities:
print obj._queryID + "==>"+ obj._docId
for var in obj._name:
print var +" "
print "----\n"
* * *
I used the following functions taken from [Python: how to save a list with
objects in a file](http://stackoverflow.com/questions/17076873/python-how-to-
save-a-list-with-objects-in-a-file):
#save list of variations
def save_data(data, path):
with open(path, "wb") as f:
pickle.dump(data, f)
#load list of variations (Correctd after comments thank you)
def load_data(var_file):
try:
with open(var_file) as f:
listDocument = pickle.load(f)
except:
listDocument = []
return listDocument
* * *
* As output I can only print the _queryID. What am I missing? I cannot print the list _name nor the _docID
Answer: Okay, a few issues.
First:
def load_data(var_file):
try:
with open(var_file) as f:
listDocument = pickle.load(f)
except:
listDocuments = []
return listDocuments
You use both `listDocument` and `listDocuments`. (Note one has a trailing
`s`). Also, you're using these the variable `listDocuments` in the outer
program which is hiding your errors. Let's rename the variable inside the
function to `data` like the `save_data` function does. We'll also rename
`var_file` to `path` for the same consistency reason.
Consider:
def load_data(path):
data = []
try:
with open(path) as f:
data = pickle.load(f)
except: pass
return data
Next, you're using `list` which is a reserved built-in -- lets change that to
`lst`. So now you have:
class Document:
_queryID = ""
_name = []
_docId = ""
def save_data(data, path):
with open(path, "wb") as f:
pickle.dump(data, f)
#load list of variations
def load_data(path):
data = []
try:
with open(path) as f:
data = pickle.load(f)
except: pass
return data
import pickle
if __name__ == "__main__":
listDocuments = []
for i in range(0,10):
e = Document()
e._queryID = str(i)
e._docId = str(i+1)
e._name.append("h"+str(i))
listDocuments.append(e)
save_data(listDocuments, "Variations.dat")
lst = load_data("Variations.dat")
for elem in lst:
print elem._queryID
print elem._docId
print elem._name
print "---"
Which works, and prints:
0
1
['h0', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'h7', 'h8', 'h9']
---
1
2
['h0', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'h7', 'h8', 'h9']
---
2
3
['h0', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'h7', 'h8', 'h9']
---
3
4
['h0', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'h7', 'h8', 'h9']
---
4
5
['h0', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'h7', 'h8', 'h9']
---
5
6
['h0', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'h7', 'h8', 'h9']
---
6
7
['h0', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'h7', 'h8', 'h9']
---
7
8
['h0', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'h7', 'h8', 'h9']
---
8
9
['h0', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'h7', 'h8', 'h9']
---
9
10
['h0', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'h7', 'h8', 'h9']
---
**EDIT**
Per your edit, you have no `listEntities` variable -- I think you mean (the
recently renamed) `lst`:
for obj in lst:
print obj._queryID + "==>"+ obj._docId
for var in obj._name:
print var +" "
print "----\n"
Lastly, if you're wondering why the `_name` variable is the same for all
instances of the `Document` class, it's because you're declaring `_name` as a
class attribute (so its the same for all instances), not an instance
attribute.
You could replace the `Document` class definition with:
class Document:
def __init__(self):
self._name = []
And you'll probably be happier with the results:
0==>1
h0
----
1==>2
h1
----
2==>3
h2
----
3==>4
h3
----
4==>5
h4
----
5==>6
h5
----
6==>7
h6
----
7==>8
h7
----
8==>9
h8
----
9==>10
h9
----
|
How to attribut a different variable to each element of list
Question: Watch out I am a beginner.
My question is: can I ask Python to attribut a different variable to each
element of a list.
I created one list of questions and one list of answer
lst_questions = ['6+11', '3+3', '9+10', '2+7', '11+8', '9+3', '11+9', '3+3', '2+4', '7+4', '4+8', '3+9']
lst_reponses = [17, 6, 19, 9, 19, 12, 20, 6, 6, 11, 12, 12]
var1 = 0
var2 = 0
var3 = 0
var4 = 0
var5 = 0
var6 = 0
var7 = 0
var8 = 0
var9 = 0
var10 = 0
var11 = 0
var12 = 0
a = 0
b = 0
c = 0
d = 0
e = 0
f = 0
g = 0
h = 0
i = 0
j = 0
k = 0
l = 0
And I want to have:
def apply_solution(lst):
a = lst.index(var1)
b = lst.index(var2)
c = lst.index(var3)
d = lst.index(var4)
e = lst.index(var5)
f = lst.index(var6)
g = lst.index(var7)
h = lst.index(var8)
i = lst.index(var9)
j = lst.index(var10)
k = lst.index(var11)
l = lst.index(var12)
#Solution
lst[a], lst[b], lst[c], lst[d], lst[e], lst[f], lst[g], lst[h], lst[i], lst[j], lst[k], lst[l] = lst[a], lst[k], lst[j], lst[i], lst[h], lst[g], lst[f], lst[e], lst[d], lst[c], lst[b], lst[l]
#Verification indice
#print a,b,c
return lst
print apply_solution(lst_reponses)
Obviously, I receive error:
a = lst.index(var1)
ValueError: 0 is not in list
How can I attribute each element of lst_reponses to var1 ... var12 I hope I
make myself clear.
Answer: Use a dict if you want to associate values:
lst_questions = ['6+11', '3+3', '9+10', '2+7', '11+8', '9+3', '11+9', '3+3', '2+4', '7+4', '4+8', '3+9']
lst_reponses = [17, 6, 19, 9, 19, 12, 20, 6, 6, 11, 12, 12]
data = dict(zip(lst_questions,lst_reponses))
{'2+4': 6, '2+7': 9, '3+3': 6, '9+10': 19, '6+11': 17, '3+9': 12, '9+3': 12, '11+9': 20, '11+8': 19, '7+4': 11, '4+8': 12}
To ask a user question and verify:
from random import choice
# "3+2" etc.. keys and correct result as value
data = dict(zip(lst_questions, lst_reponses))
# get random key
question = choice(data.keys())
inp = raw_input("What is {}".format(question))
# is user answer match the value
if int(inp) == data[question]:
print("Well done")
else:
print("Incorrect")
|
Python Tkinter check radio button state before proceed
Question: I have this code which is working
import Tkinter as tk
from Tkinter import *
LARGE_FONT= ("Verdana", 12)
class ChangePages(tk.Tk):
def __init__(self, *args, **kwargs):
tk.Tk.__init__(self, *args, **kwargs)
container = tk.Frame(self)
container.pack()
container.grid_rowconfigure(0, weight=1)
container.grid_columnconfigure(0, weight=1)
self.frames = {}
for F in (MainPage, Page01, Page02):
frame = F(container, self)
self.frames[F] = frame
frame.grid(row=0, column=0, sticky="nsew")
self.show_frame(MainPage)
def show_frame(self, cont):
frame = self.frames[cont]
frame.tkraise()
#MainPage
class MainPage(tk.Frame):
def __init__(self, parent, controller):
tk.Frame.__init__(self,parent)
button1=Button(self,text='Go To Page 1',fg='blue',font=('Helvetica',26),height=5, width=20,command=lambda: controller.show_frame(Page01)).grid(row=1,column=1)
#Page01
class Page01(tk.Frame):
def __init__(self, parent, controller):
option1 = IntVar()
option2 = IntVar()
option3 = IntVar()
tk.Frame.__init__(self, parent)
f = Frame(self)
f.pack(side='left')
label1=Label(f,text='Select options',fg='blue', font=("Arial", 36, "bold"),width=54, relief='solid').grid(row=1,column=1,columnspan=3)
labelspacing=Label(f,text='Option 1 ',font=("Arial", 18, "bold"),width=20,height=1).grid(row=2,column=1)
labelspacing=Label(f,text='Option 2 ',font=("Arial", 18, "bold"),width=20,height=1).grid(row=2,column=2)
labelspacing=Label(f,text='Option 3',font=("Arial", 18, "bold"),width=20,height=1).grid(row=2,column=3)
buttonoption11=Radiobutton(f, text="Option 1 - A", variable=option1, value=1, indicatoron=0, fg='blue',font=('Helvetica',26),height=1, width=20).grid(row=3,column=1)
buttonoption21=Radiobutton(f, text="Option 2 - A", variable=option2, value=1, indicatoron=0, fg='blue',font=('Helvetica',26),height=1, width=20).grid(row=3,column=2)
buttonoption31=Radiobutton(f, text="Option 3 - A", variable=option3, value=1, indicatoron=0, fg='blue',font=('Helvetica',26),height=1, width=20).grid(row=3,column=3)
buttonoption12=Radiobutton(f, text="Option 1 - B", variable=option1, value=2, indicatoron=0, fg='blue',font=('Helvetica',26),height=1, width=20).grid(row=4,column=1)
buttonoption22=Radiobutton(f, text="Option 2 - B", variable=option2, value=2, indicatoron=0, fg='blue',font=('Helvetica',26),height=1, width=20).grid(row=4,column=2)
buttonoption32=Radiobutton(f, text="Option 3 - B", variable=option3, value=2, indicatoron=0, fg='blue',font=('Helvetica',26),height=1, width=20).grid(row=4,column=3)
buttonoption23=Radiobutton(f, text="Option 2 - C", variable=option2, value=3, indicatoron=0, fg='blue',font=('Helvetica',26),height=1, width=20).grid(row=5,column=2)
buttonnback=Button(f,text='Back',fg='blue',font=('Helvetica',26),height=1,width=15,command=lambda: controller.show_frame(MainPage)).grid(row=10,column=1)
buttonnext=Button(f,text='Next',fg='blue',font=('Helvetica',26),height=3,width=15,command=lambda: controller.show_frame(Page02)).grid(row=10,column=2)
#Page02
class Page02(tk.Frame):
def __init__(self, parent, controller):
tk.Frame.__init__(self, parent)
label = tk.Label(self, text="Page 02!!!", font=LARGE_FONT)
label.pack(pady=10,padx=10)
button1 = tk.Button(self, text="Back to Home",
command=lambda: controller.show_frame(MainPage))
button1.pack()
button2 = tk.Button(self, text="Page 01",
command=lambda: controller.show_frame(PageSub35t))
button2.pack()
#Root loop
app = ChangePages()
app.mainloop()
What I want to do is:
When the user presses next in pag01, I want to check the states of radio
buttons. For example if the user chose "Option 1 -A" and "Option 2 -C", I want
to popup a message saying "You are not allowed to choose 2c! You can choose 2c
only if 1B is selected" and not let him to go to page02.
Answer: I understand your problem and how you want to solve it. But, from an user
experience point of view there is a better way of doing this. Instead of
showing the user options that the user can't choose and displaying error
messages, it is better to **only show the user what he can choose**. Scenario
example:
> User selected Option 1 -A
>
> The Radio button Option 2 -C turns grey(disabled)
Here is a demo:
#very bad code
#http://stackoverflow.com/questions/28900100/python-tkinter-check-radio-button-state-before-proceed/28901595#28901595
try:#3.X
import tkinter as tk
except ImportError:#2.X
import Tkinter as tk
#use ttk cascade style techniques instead !!!
LARGE_FONT= ("Verdana", 12)
class ChangePages(tk.Tk):
def __init__(self, *args, **kwargs):
tk.Tk.__init__(self, *args, **kwargs)
container = tk.Frame(self)
container.pack() #use grid everywhere
container.grid_rowconfigure(0, weight=1)
container.grid_columnconfigure(0, weight=1)
self.frames = {}
for F in (MainPage, Page01, Page02):
frame = F(container, self)
self.frames[F] = frame
frame.grid(row=0, column=0, sticky="nsew")
self.show_frame(MainPage)
def show_frame(self, cont):
frame = self.frames[cont]
frame.tkraise()
class MainPage(tk.Frame):
def __init__(self, parent, controller):
tk.Frame.__init__(self,parent)
button1 = tk.Button(self,text='Go To Page 1',fg='blue',font=('Helvetica',26),height=5, width=20,command=lambda: controller.show_frame(Page01)).grid(row=1,column=1)
class Page01(tk.Frame):
def __init__(self, parent, controller):
option1 = tk.IntVar()
option2 = tk.IntVar()
option3 = tk.IntVar()
tk.Frame.__init__(self, parent)
f = tk.Frame(self)
f.pack(side='left')
label1 = tk.Label(f,text='Select options',fg='blue', font=("Arial", 36, "bold"),width=54, relief='solid').grid(row=1,column=1,columnspan=3)
#not used
#labelspacing = tk.Label(f,text='Option 1 ',font=("Arial", 18, "bold"),width=20,height=1).grid(row=2,column=1)
#labelspacing = tk.Label(f,text='Option 2 ',font=("Arial", 18, "bold"),width=20,height=1).grid(row=2,column=2)
#labelspacing = tk.Label(f,text='Option 3',font=("Arial", 18, "bold"),width=20,height=1).grid(row=2,column=3)
buttonoption21 = tk.Radiobutton(f, text="Option 2 - A", variable=option2, value=1, indicatoron=0, fg='blue',font=('Helvetica',26),height=1, width=20)
buttonoption21.grid(row=3,column=2)
buttonoption22 = tk.Radiobutton(f, text="Option 2 - B", variable=option2, value=2, indicatoron=0, fg='blue',font=('Helvetica',26),height=1, width=20)
buttonoption22.grid(row=4,column=2)
buttonoption32 = tk.Radiobutton(f, text="Option 3 - B", variable=option3, value=2, indicatoron=0, fg='blue',font=('Helvetica',26),height=1, width=20)
buttonoption32.grid(row=4,column=3)
buttonoption23 = tk.Radiobutton(f, text="Option 2 - C", variable=option2, value=3, indicatoron=0, fg='blue',font=('Helvetica',26),height=1, width=20)
buttonoption23.grid(row=5,column=2)
# this entire list is affected by switch_all_button()
list_conditional = [buttonoption21, buttonoption22, buttonoption32, buttonoption23]
def switch_button(button, active=True):
if button is not None:
button['state'] = {True: tk.NORMAL, False: tk.DISABLED}[active]
#here you can also unselect
def switch_all_button(active=True):
for button in list_conditional:
switch_button(button, active=active)
def after_option_command(what_button_should_be_disabled=None):
def after_option():
switch_all_button(active=True)
switch_button(what_button_should_be_disabled, active=False)
return after_option
# to update the state of other buttons after 1 is pressed
# use command=after_option_command(button_x) in the constructor
buttonoption11 = tk.Radiobutton(f, command=after_option_command(buttonoption23), text="Option 1 - A", variable=option1, value=1, indicatoron=0, fg='blue',font=('Helvetica',26),height=1, width=20)
buttonoption11.grid(row=3,column=1)
buttonoption12 = tk.Radiobutton(f, command=after_option_command(), text="Option 1 - B", variable=option1, value=2, indicatoron=0, fg='blue',font=('Helvetica',26),height=1, width=20)
buttonoption12.grid(row=4,column=1)
buttonnback = tk.Button(f,text='Back',fg='blue',font=('Helvetica',26),height=1,width=15,command=lambda: controller.show_frame(MainPage)).grid(row=10,column=1)
buttonnext = tk.Button(f,text='Next',fg='blue',font=('Helvetica',26),height=3,width=15,command=lambda: controller.show_frame(Page02)).grid(row=10,column=2)
class Page02(tk.Frame):
def __init__(self, parent, controller):
tk.Frame.__init__(self, parent)
label = tk.Label(self, text="Page 02!!!", font=LARGE_FONT)
label.pack(pady=10,padx=10)
button1 = tk.Button(self, text="Back to Home",
command=lambda: controller.show_frame(MainPage))
button1.pack()
button2 = tk.Button(self, text="Page 01",
command=lambda: controller.show_frame(PageSub35t))
button2.pack()
#Root loop
app = ChangePages()
app.mainloop()
You don't need to import tkinter twice. Use this syntax
try: # 3.X
import tkinter as tk
except ImportError: # 2.X
import Tkinter as tk
will force you to use `tk.` every time you are using a tkinter object explicit
better than implicit. It will also work with Python 3.
#Page02
class Page02(tk.Frame):
this is a useless comment because it doesn't add value. The code is poor
quality, but here's how to fix it:
* Follow PEP8
* Do not use classes as keys for dicts
* Instead of describing the look inside your main code, do it outside or on top of the file using `ttk` and `ttk.Style()`
* Widget.grid method returns None, which means
`buttonoption11 = tk.Radiobutton(f,
command=after_option_command(buttonoption23), text="Option 1 - A",
variable=option1, value=1, indicatoron=0,
fg='blue',font=('Helvetica',26),height=1, width=20).grid(row=3,column=1)`
* buttonoption11 is not a `tk.Radiobutton` but `None`
* use .grid everywhere unless you have a very good reason not to
* use for loops to create similar widgets
**Warning** the code I gave is not fixed, do not use it before you apply all
tips given above
edit: works as expected in the comment, read the comments to extend the API
|
Django REST || Python? Class attributes as a key-value pair array
Question: I'm currently doing the [Django REST Framework tutorial](http://www.django-
rest-framework.org/tutorial/1-serialization/) and I came across something when
testing that confused me.
>>> snippet =Snippet(code='foo = "bar"\n')
>>> snippet.save()
>>> snippet = Snippet(code='print "hello, world"\n')
>>> snippet.save()
>>> serializer = SnippetSerializer(snippet)
>>> serializer.data
>>> {'style': 'friendly', 'code': u'print "hello, world"\n', 'language': 'python', 'title': u'', 'linenos': False, 'pk': 2}
Specifically that last line. I don't define a `data` class or instance
attribute. The `SnippetSerializer` class is defined as the following:
from django.forms import widgets
from rest_framework import serializers
from snippets.models import Snippet, LANGUAGE_CHOICES, STYLE_CHOICES
class SnippetSerializer(serializers.Serializer):
pk = serializers.IntegerField(read_only=True)
title = serializers.CharField(required=False, allow_blank=True, max_length=100)
code = serializers.CharField(style={'base_template': 'textarea.html'})
linenos = serializers.BooleanField(required=False)
language = serializers.ChoiceField(choices=LANGUAGE_CHOICES, default='python')
style = serializers.ChoiceField(choices=STYLE_CHOICES, default='friendly')
def create(self, validated_data):
"""
Create and return a new 'Snippet' instance, given the validated data.
"""
return Snippet.objects.create(**validated_data)
def update(self, instance, validated_data):
"""
Update and return an existing 'Snippet' instance, given the validated data.
"""
instance.title = validated_data.get('title', instance.title)
instance.code = validated_data.get('code', instance.code)
instance.linenos = validated_data.get('linenos', instance.linenos)
instance.language = validated_data.get('language', instance.language)
instance.style = validated_data.get('style', instance.style)
instance.save()
return instance
I see that the `SnippetSerializer` class is relatives with
`serializers.Serializer` (right?), but it doesn't seem there is a `data`
attribute there either. It obviously works and allows me to access all of
`SnippetSerializers` attributes as a key-value pair array. I just couldn't
find documentation of this anywhere. Is `data` a reserved word in python? Is
this something unique to Django REST? Or is there some inheritance that I'm
not seeing?
Thank you in advance!
Answer: `data` is a property on the BaseSerializer class, from which Serializer
inherits. See [the code](https://github.com/tomchristie/django-rest-
framework/blob/master/rest_framework/serializers.py#L200).
|
Issue with Selenium and Tableau Server
Question: Trying to change a filter on tableau dashboard hosted on tableau server
through selenium script.
Need to know whether there are some restrictions on tableau server or do we
have any work around for the same.
Here is the code:
from selenium import webdriver
from selenium.webdriver.support import ui
from selenium.webdriver.common.keys import Keys
import time
driver = webdriver.Chrome('C:\\Python27\\Scripts\\chromedriver.exe')
driver.get("PATH Name")
dropdowmclick = driver.find_element_by_class_name("tabComboBoxName")
dropdowmclick.click()
time.sleep(20)
driver.close()
Require help here.
Answer: Selenium is a browser automation tool and mimics real user actions on the
page. Generally speaking, it doesn't matter what is there under test in the
browser.
Just one specific note about `tableau`: since it uses AJAX a lot and different
parts of a page are loaded asynchronously, you would have to use [Explicit
Waits](http://selenium-python.readthedocs.org/en/latest/waits.html#explicit-
waits) a lot - avoid hardcoded time sleep intervals and explicitly wait for
specific elements before interacting with them.
|
Errors when I start the Python shell, errors from a script I ran a week ago
Question: I've been learning python and I there is a problem with my Python interactive
shell on one of my systems. It runs a script on every python-interactive-mode
start(without arguments). I don't know where to look for a process that does
this, I've programmed a lot of small scripts on this system, and I can see
what script is messing around,
When I do this:
user@Host ~/Python Scripts> python
I get:
Python 3.4.2 (default, Feb 21 2015, 22:19:02)
[GCC 4.9.2 20150212 (Red Hat 4.9.2-6)] on linux
Type "help", "copyright", "credits" or "license" for more information.
# ! / u s r / b i n / e n v p y t h o n
finished
Failed calling sys.__interactivehook__
Traceback (most recent call last):
File "/usr/local/opt/python-3.4.2/lib/python3.4/site.py", line 396, in register_readline
import rlcompleter
File "/usr/local/opt/python-3.4.2/lib/python3.4/rlcompleter.py", line 161, in <module>
readline.set_completer(Completer().complete)
AttributeError: 'module' object has no attribute 'set_completer'
>>> quit()
Here is the file I ran, and is run on every python start:
#!/usr/bin/env python
try:
number = int(input("Enter a number: "))
print(number)
aFile = open('modules.py')
for i in aFile:
print(aFile.readline(), end=' ')
except ValueError:
print('Not a number, please re-enter:')
number = int(input('Enter a number: '))
print(number)
except IOError:
print('Cannot open file')
print('finished')
What is causing this and how do I fix it?
EDIT #1
The system is Fedora 21, the file modules.py and the script that runs on start
of the interactive shell are scripts that have never been edited on a Windows
system.
The system has not been rebooted for 11 day's.
Here is:
~/Python Scripts> file tryexcept.py
tryexcept.py: Python script, ASCII text executable
EDIT #2
I have a readline.py in my current working directory:
~/Python Scripts> ls | grep readline
readline.py
Answer: The last part of `rlcompleter.py` trys to import readline and then runs the
line you error on.
try:
import readline
except ImportError:
pass
else:
readline.set_completer(Completer().complete)
# Release references early at shutdown (the readline module's
# contents are quasi-immortal, and the completer function holds a
# reference to globals).
atexit.register(lambda: readline.set_completer(None))
There must be a `readline.py` file somewhere in your path that you are
importing instead of the actual python module. If you don't have a readline.py
but once had then look for a `readline.pyc` file.
Put a `import readline;print(readline.__file__)` in your interpreter and see
what exactly you are importing
|
How to append the logs in python
Question: There are two files named file1 and file2 in the python project.
In file1.py , Iam capturing the log to file 'sample.log' and executing the
file2.py through os.system() command. In file2.py, I am opening the sample log
file sample.log in appending mode and sending logs to that file.
I have executed the file1.py, even though I have opened the log file(file2.py)
in append mode , I am unable to see the file2.py log. File2 contents are
overridden by file1 contents.
How Can I append file2.py logs with file1.py logs in sample.log?
**file1.py**
import logging
import os
logFile = 'sample.log'
logging.basicConfig( filename = logFile,filemode = 'w',level = logging.DEBUG,format = '%(asctime)s - %(levelname)s: %(message)s',\
datefmt = '%m/%d/%Y %I:%M:%S %p' )
logging.debug("Starting of the file1")
os.system("python file2.py")
for i in range(0,2):
logging.debug("Iam in file1")
**file2.py:**
import logging
logFile = 'sample.log'
logging.basicConfig( filename = logFile,filemode = 'a',level = logging.DEBUG,format = '%(asctime)s - %(levelname)s: %(message)s',\
datefmt = '%m/%d/%Y %I:%M:%S %p' )
for i in range(0,2):
logging.debug("Iam in file2")
Need the output like this
> 03/06/2015 08:02:03 PM - DEBUG: Starting of the file1
>
> 03/06/2015 08:02:03 PM - DEBUG: Iam in file2
>
> 03/06/2015 08:02:03 PM - DEBUG: Iam in file2
>
> 03/06/2015 08:02:03 PM - DEBUG: Iam in file1
>
> 03/06/2015 08:02:03 PM - DEBUG: Iam in file1
but getting like this:
> 03/06/2015 08:02:49 PM - DEBUG: Starting of the file1
>
> 03/06/2015 08:02:49 PM - DEBUG: Iam in file1
>
> 03/06/2015 08:02:49 PM - DEBUG: Iam in file1
Could someone help in this to get my expected output, Thanks in Advance
Answer: There are two main faults with your approach:
1. There should only be one logger on a file. If you are going to use `os.system` you'll have to use two log files because you can't open a duplicate Logger handle in file2.py.
2. You have different write-modes which causes a race condition. It could be that your `filemode='a'` completes all of its writes and then `filemode='w'` overwrites the log file from the start, clearing all previously written "file2" logging output.
|
Why do I have to open my csv twice?
Question: Assume I have a csv file where I first need to get the number of rows in order
to initialize an array. Then I want to fill the array with the rows from the
file (but only some columns):
import csv
import numpy
with open('a_csv_file', 'rb') as f:
num_row = sum(1 for row in f)
myarray = numpy.empty(shape=(num_row, 50), dtype=numpy.int16)
infileReader = csv.reader(f)
for row in infileReader:
row_number = infileReader.line_num - 1
my_array[row_number] = [int(row[7])] + row[21:70]
However, the script doen't enter the row-loop. But `print infileReader` is
confirms the existence of `infileReader`.
Now I open `a_csv_file.csv` twice, but I think that's not pythonic:
with open('a_csv_file', 'rb') as f:
num_row = sum(1 for row in f)
myarray = numpy.empty(shape=(num_row, 50), dtype=numpy.int16)
with open('a_csv_file', 'rb') as f:
infileReader = csv.reader(f)
for row in infileReader:
row_number = infileReader.line_num - 1
my_array[row_number] = [int(row[7])] + row[21:70]
Why do I have to open the csv file twice?
Answer: When you iterate through the file (to count the length), your position in the
file is left at the end. When you try and iterate over it again, there is
nothing left so the loop is not entered. Before you create the `csv.reader`
call `f.seek(0)` to return to the start.
See the docs for the `seek` method
[here](https://docs.python.org/3.4/library/io.html#io.IOBase.seek)
|
Redirect with HttpResponseRedirect to another function in python
Question: I have a function :
def drawback(request,problem_id)
and I want in the end of this function to redirect to another page that is
called from function
def show(request,problem_id)
I tried with
return HttpResponseRedirect(reverse('show',kwargs={'problem_id':10}))
return HttpResponseRedirect(reverse('show',kwargs={'problem_id':'10'}))
return HttpResponseRedirect(reverse('show',args=[10]))
return HttpResponseRedirect(reverse('show',args=(10))
Everything I found in other sites. But I receive the error
Exception Type: NoReverseMatch
Exception Value:
Reverse for 'show' with arguments '()' and keyword arguments '{'problem_id': '10'}' not found.
or
Exception Value: Reverse for 'show' with arguments '(u'10',)' and keyword arguments '{}' not found.
This function and page works when I call it through html with a button. When I
try to redirect from drawback function is not working.
urls.py
from django.conf.urls.defaults import *
from views import *
import settings
from django.conf import settings as rootsettings
urlpatterns = patterns('',
# authentication
(r'^start_auth', start_auth),
(r'^after_auth', after_auth),
# screens
(r'^problems/codelookup$', code_lookup),
# TESTING
(r'^problems/test$', test_message_send),
(r'^donnorsTool/$', problem_list),
(r'^problems/delete/(?P<problem_id>[^/]+)', archived_problem),
(r'^problems/edit/(?P<problem_id>[^/]+)', edit_problem),
(r'^problems/restore/(?P<problem_id>[^/]+)', restore_problem),
(r'^problems/new$', new_problem),
(r'^problems/archived$', archived_problems),
(r'^donnorsTool/show/(?P<problem_id>[^/]+)', show),
(r'^donnorsTool/consent/(?P<problem_id>[^/]+)/(?P<counter>[^/]+)', consent),
(r'^donnorsTool/withdraw/(?P<problem_id>[^/]+)/(?P<counter>[^/]+)', withdraw),
# static
## WARNING NOT FOR PRODUCTION
(r'^static/(?P<path>.*)$', 'django.views.static.serve', {'document_root': rootsettings.SERVER_ROOT_DIR + settings.STATIC_HOME}),
)
Answer: Just call it like a function :
def drawback(request,problem_id)
...
...
return show(request,10)
|
How to interact with python's subprocess as a continuous session
Question: I need to implement a filter in python, which pick out specific outputs from a
Linux command-line dictionary tool. I need to:
1. Get a set of words from a file
2. Lookup each word: 1) if word not contains, skip it; 2) else if it is a verb, save the definition.
To test the code, I wrote two python file：
# name.py
import sys
while True:
print 'name => Q: what is your name?'
sys.stdout.flush()
name = raw_input()
if name == 'Exit':
break
print 'name => A: your name is ' + name
sys.stdout.flush()
# test.py
import subprocess
child = subprocess.Popen(r'python name.py',
stdin = subprocess.PIPE,
stdout = subprocess.PIPE,
stderr = subprocess.STDOUT,
shell = True)
commandlist = ['Luke\n', 'Mike\n', 'Jonathan\n', 'Exit\n']
for command in commandlist:
child.stdin.write(command)
child.stdin.flush()
output = child.stdout.readline()
print 'From PIPE: ' + output
while child.poll() is None:
print 'NOT POLL: ' + child.stdout.readline()
child.wait()
The output is
From PIPE: name => Q: what is your name?
From PIPE: name => A: your name is Luke
From PIPE: name => Q: what is your name?
From PIPE: name => A: your name is Mike
# these lines need to start with "From PIPE" ...
NOT POLL: name => Q: what is your name?
NOT POLL: name => A: your name is Jonathan
NOT POLL: name => Q: what is your name?
NOT POLL:
The later output is read during the `while` loop rather than the `for` loop in
`test.py`. What is the reason?
Due to the demand, I need to get the whole output each time it input a new
command. It seems like a dialog session. So the `subprocess.communicate()` is
useless there, for it always terminates current subprocess. How to implement
this demand?
Answer: The basic reason `subprocess` insists you use `.communicate()` is because it's
possible for deadlock to occur otherwise. Suppose you're writing to the
process's stdin, while the process is writing to its stdout. If the pipe
buffers fill up, the writes will block until a read occurs. Then you're both
waiting for each other and no progress can be made. There are several ways to
deal with this:
1. Use separate threads. Assign one to stdin and the other to stdout. That way, if one pipe blocks, you're still servicing the other.
2. Use `select` to multiplex over the pipes. Only interact with pipes which are ready for you. You should also enable `O_NONBLOCK` on the pipes using `fcntl`, so you don't accidentally fill the buffers. Used correctly, this will prevent the pipes from ever blocking, so you can't deadlock. **This doesn't work under Windows** , because you can only do `select` on sockets there.
|
How do I select a random element from a 2d list
Question: I'm trying to select a random element in a 2D list in python. I'm creating a
blackjack game.
> I'm aware of how long and non-optimized this code is, but I'm new to
> programming and I want to make mistakes to learn.
>
> Here's the initial code that I have set up. I create the suits (spades,
> clubs, hearts, diamonds). I append it to the list called list_of_cards which
> was initialized as an empty array.
>
> Then I have another list called player_card for the player to view. Here it
> is in reference.
list_of_suits= [] #Creating list of cards
player_card = []
king_of_spades = 10 #Creating face cards for the spades deck.
queen_of_spades = 10
jack_of_spades = 10
king_of_clubs = 10
queen_of_clubs = 10
jack_of_clubs = 10
king_of_hearts = 10
queen_of_hearts = 10
jack_of_hearts = 10
king_of_diamonds = 10
queen_of_diamonds = 10
jack_of_diamonds = 10
ace_of_spades = [1,11] # Aces are either 1 or 11
ace_of_clubs = [1,11]
ace_of_hearts = [1,11]
ace_of_diamonds = [1,11]
spades = [ace_of_spades,2,3,4,5,6,7,8,9,10, jack_of_spades, queen_of_spades, king_of_spades]
clubs = [ace_of_clubs,2,3,4,5,6,7,8,9,10, jack_of_clubs, queen_of_clubs, king_of_clubs]
hearts = [ace_of_hearts,2,3,4,5,6,7,8,9,10, jack_of_hearts, queen_of_hearts, king_of_hearts]
diamonds = [ace_of_diamonds,2,3,4,5,6,7,8,9,10, jack_of_diamonds, queen_of_diamonds, king_of_diamonds]
list_of_suits.append(spades)
list_of_suits.append(clubs)
list_of_suits.append(hearts)
list_of_suits.append(diamonds)
> This is the selector for a random card. It will iterate through the array to
> select one of the four cards randomly. Next, it will go into that array and
> choose a random card.
random_list_of_suits = random.choice(list_of_suits)
random_card_number = random.choice(random_list_of_suits)
random_list_of_suits.remove(random_card_number)
player_card.append(random_card_number)
print player_card
print list_of_suits
> Here's what I'm trying to figure out: How do I create a new random number
> each time?
>
> I'm kind of stuck and I tried putting it through a for loop, but if I put
> the random_card_number in a loop, it will select the same random card that
> it did initially four times.
Answer:
import random
list2d = [range(0, 5), range(5, 10), range(10, 15), range(15, 20)]
for i in range(0, 10):
random_suite = random.choice(list2d)
random_card = random.choice(random_suite)
print random_suite, random_card
output:
[5, 6, 7, 8, 9] 7
[5, 6, 7, 8, 9] 5
[5, 6, 7, 8, 9] 5
[10, 11, 12, 13, 14] 11
[10, 11, 12, 13, 14] 13
[10, 11, 12, 13, 14] 12
[10, 11, 12, 13, 14] 14
[10, 11, 12, 13, 14] 10
[10, 11, 12, 13, 14] 10
[0, 1, 2, 3, 4] 2
|
Create a file object from raw binary information in Python
Question: ### Question
What is a clean way to create a file object from raw binary information in
Python?
### More Info
The reason I need to do this is because I have the raw binary information
comprising a jpeg image stored in ram. I need to put it inside some kind of
file object so that I can resize the image using Python's
[Pillow](http://pillow.readthedocs.org/en/latest/about.html) library.
According to the [pillow
documentation](http://pillow.readthedocs.org/en/latest/reference/Image.html),
the file object needs to implement the `read()`, `seek()`, and `tell()`
methods.
The file object must implement read(), seek(), and tell() methods, and be opened in binary mode.
Answer: I was able to find a mention of how to handle this situation under the
documentation for `PIL.Image.frombytes`:
...If you have an entire image in a string, wrap it in a BytesIO object,
and use open() to load it.
This is what I ended up with that worked using `BytesIO`:
import io
import PIL
from PIL.Image import Image
file_body = <binary image data>
t_file = io.BytesIO(file_body)
img = PIL.Image.open(t_file)
Note: The comments mention `tempfile.SpooledTemporaryFile`. This seems like it
should have worked, but it did not for some reason.
|
Python Snakefood module import generalized failure
Question: I want to run [snakefood](http://furius.ca/snakefood/doc/snakefood-doc.html)
(an AST-based dependency graph analyser; source code can be found
[here](https://bitbucket.org/blais/snakefood/src/e0a74fa6260dcd44716d40b4eb404ca024323eac/lib/python/snakefood/gendeps.py?at=default)).
My project has a structureinvolving several levels of Python packages, like
this:
myproject
|code
|Utils
|AdaptedConfigParser
Configs_Parser.py
...
...
main.py
However, when I start running snakefood on the root directory of my project it
claims that it can't find the modules from my Python package being imported:
$ sfood --internal --follow --ignore-unused ./PycharmProjects/myproject/ > ~/static_analysis.txt
WARNING : Line 9: Could not import module 'myproject.Utils.AdaptedConfigParser.Configs_parser'
I tried to get around it by adding a `.pth` file with the project root to the
`lib/python2.7/site-packages`
Now when I call python with that virtual environment activated from anywhere,
I can do the following:
$ python
Python 2.7.6rc1 (default, Jan 19 2014, 18:57:40)
[GCC 4.4.7 20120313 (Red Hat 4.4.7-4)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import myproject.Utils.AdaptedConfigParser.Configs_parser
>>>
And it works just fine.
However, when snakefood is launched with that virtual environement, it still
returns the same error.
$ sfood --internal --follow --ignore-unused ./PycharmProjects/myproject/ > ~/static_analysis.txt
WARNING : Line 9: Could not import module 'myproject.Utils.AdaptedConfigParser.Configs_parser'
At this point I don't even understand where the problem with imports could
come from.
In addition to that, when `--internal` flag is taken away, it fails imports
even of the python `builtin` module, which doesn't make any sense to me:
WARNING : Line 80: Could not import module 'builtins'
WARNING : Line 190: Could not import module 'pyamg'
Have anyone encountered such a problem previously? If yes, is there a way of
getting around it?
Answer: I had similar issues, turns out the warning in my case was generated because
of `__all__` declarations.
e.g.
__all__ = ['abc',
'aaa',
...
]
Above code gives out the warnings:
WARNING : Line xx: Could not import module 'abc'
WARNING : Line xx: Could not import module 'aaa'
I modified the warning constant `ERROR_IMPORT` within
`snakefood\lib\python\find.py` to add the name of the file where the error
occurs along with the line number and module name. That way you can target the
specific file and line number pretty much figure out the problem.
Hope this helps!
|
How does the code know when to split into a line?
Question: So I was learning on how to download files from the web using python but got a
bit thrown by one part of the code.
Here is the code:
from urllib import request
def download_stock_data(csv_url):
response = request.urlopen(csv_url)
csv = response.read()
csv_str = str(csv)
lines = csv_str.split("\\n")
dest_url = r"stock.csv"
fx = open(dest_url, "w")
for line in lines:
fx.write(line + "\n")
fx.close()
I don't quite understand the code in the variable lines. How does it know when
to split into a new line on a csv file ?
Answer: A csv file is essentially just a text file will comma separated data but they
also contain new lines (via the newline ascii character).
If there a csv file with a long single comma separated line for line in lines:
would only see the single line.
You can open it up in notepad++ or something to see the raw .csv file. Excel
will put data seperated by commas in a cell,and data on a new line into a new
row.
|
Failed to run Python script with Conda
Question: I tried to install menpo like in [this
tutorial](http://www.menpo.org/installation/windows/index.html). After that I
installed menpofit, menpo3d and menpodetect:
> conda install -c menpo menpofit
>
> conda install -c menpo menpo3d
>
> conda install -c menpo menpodetect
Next I ran this python script from CMD(_python testPy.py_):
import menpo.io as mio
from menpo.visualize import visualize_images
images = list(mio.import_images('A:/img/*.png'))
visualize_images(images)
And got this output:  What am I doing wrong and how I can
fix it?
Answer: It seems that `visualize_images` is meant to be used from `ipython-notebook`.
Calling it in a regular `python` script does not seem to be intended by the
authors.
See also the example in the [`Visualizing
Objects`](http://menpo.readthedocs.org/en/latest/userguide/visualization.html#visualizing-
a-list-of-2d-images) section of the docs:
%matplotlib inline
import menpo.io as mio
from menpo.visualize import visualize_images
# import_images is a generator, so we must exhaust the generator before
# we can visualize the list. This is because the widget allows you to
# jump arbitrarily around the list, which cannot be done with generators.
images = list(mio.import_images('./path/to/images/*.jpg'))
visualize_images(images)
|
Python won't advance
Question: Question: What would be the issue if python continues to ask for the same
input over and over again, and won't advance to the end of the program?
Where do you want to go? X
And how many days will you be staying in X? 1
And how many days will you be staying in X? 2
And how many days will you be staying in X? 164
And how many days will you be staying in X? 59
...
Here's the relevant part of the code:
# Import modules
import destinations
import currency
save_itinerary = True
main_function = True
while (main_function):
# Determine length of stay
while True:
try:
length_of_stay = int(input("And how many days will you be staying in " + destinations.destination[0] + "? "))
# Check for non-positive input
if (length_of_stay <= 0):
print("Please enter a positive number of days.")
continue
except ValueError:
print("The value you entered is invalid. Only numerical values are valid.")
break
else:
break
Answer: The reason your code is looping forever is that you have two nested `while`
loops, and you never break out of the outer one. You do use `break` statements
to exit the inner loop, but the condition for the outer loop is never changed,
and you never execute a `break` at the right level to exit it.
Here's what I think a better version of your code would be:
# get rid of the outer while loop, which was never ending
while True:
try:
length_of_stay = int(input("And how many days will you be staying in " + destinations.destination[0] + "? "))
if (length_of_stay <= 0):
print("Please enter a positive number of days.")
continue
except ValueError:
print("The value you entered is invalid. Only numerical values are valid.")
# don't break here, you want to stay in the loop!
else:
break
I've used comments to indicate my changes.
You could also move the `else: break` block up and indent it so that it is
attached to the `if` statement, rather than the `try`/`except` statements (and
then get rid of the unnecessary `continue` statement). That's makes the flow a
bit more obvious, though there's not really anything wrong with how it is now.
|
Biopython: ImportError: No module named TreeConstruction
Question: Someone knows why I get the following error?
>>> from Bio.Phylo.TreeConstruction import DistanceCalculator, DistanceTreeConstructor
Traceback (most recent call last):
File "<pyshell#6>", line 1, in <module>
import Bio.Phylo.TreeConstruction
ImportError: No module named TreeConstruction
And also:
>>> from Bio.Phylo.Consensus import *
Traceback (most recent call last):
File "<pyshell#9>", line 1, in <module>
from Bio.Phylo.Consensus import *
ImportError: No module named Consensus
Thanks to all for you time =)
Answer: Ok. Fixed!
The problem was that in the python IDLE, the version of biopython was 1.63,
whereas the code
>>>from Bio.Phylo.TreeConstruction import DistanceCalculator, DistanceTreeConstructor
works nice for version 1.65. So, the solution was delete the folder where
biopython 1.63 was installed and download and later (re)install the biopython
1.65.
|
Counting matches / Comparing two text files in python with utf-8 encoding
Question: i'm trying to compare two files in utf-8, gold_standard_1.txt with 2553 lines
and output_test1.txt with 2476 lines, both disordered, and count if a line in
one file matches with another line in the other text file (not necessary same
line numbers).
I have been trying many alternatives, like zip, intersections etc but does not
work.
Samples:
gold_standard_1.txt:
En Prep
total Adj
, Punt
los Det
organizadores NC
de Prep
la Det
feria NC
esperan V
en Prep
La_Habana NP
a Prep
por_lo_menos Adv
150 Num
editoriales NC
de Prep
Europa NP
, Punt
América NP
y Conj
Asia NP
, Punt
donde Pron
por Prep
primera Adj
vez NC
concurrirán V
representantes NC
de Prep
Alemania NP
y Conj
Japón NP
, Punt
además_de Prep
las Det
habituales Adj
de Prep
México NP
, Punt
Venezuela NP
, Punt
Argentina NP
y Conj
España NP
, Punt
según Prep
dijo V
el Det
presidente NC
del Prep
Instituto_Cubano_del_Libro NP
, Punt
Pablo_Pacheco NP
. Fin
Para Prep
la Det
comercialización NC
la Det
feria NC
dispondrá V
de Prep
cerca_de Prep
300.000 Num
ejemplares Adj
de Prep
México NP
, Punt
Santo_Domingo NP
, Punt
Ecuador NP
, Punt
Venezuela NP
, Punt
Argentina NP
, Punt
Chile NP
, Punt
España_e_Inglaterra NP
. Fin
Durante Prep
la Det
feria NC
se Pron
desarrollará V
un Det
programa NC
para Prep
la Det
lectura NC
de Prep
textos NC
, Punt
tertulias NC
, Punt
encuentros NC
de Prep
escritores NC
y Conj
la Det
presentación NC
de Prep
una Det
muestra V
especializada Adj
dedicada Adj
al Prep
medio_ambiente NC
y Conj
la Det
alimentación NC
. Fin
Entre Prep
los Det
invitados NC
figuran V
el Det
director NC
general Adj
del Prep
Centro_Regional_del_Libro_para_América_Latina NP
y Conj
el Det
Caribe NP
, Punt
José_Salgar NP
, Punt
la Det
presidenta NC
de Prep
la Det
Dirección_del_Libro_de_la_UNESCO NP
, Punt
Milagros_del_Corral NP
y Conj
Alfredo_Weisflog NP
, Punt
quien Pron
encabeza V
el Det
grupo NC
interamericano Adj
de Prep
editores NC
. Fin
También Adv
ha VAux
sido V
anunciada Adj
la Det
presencia NC
de Prep
varios Det
autores NC
latinoamericanos Adj
como Conj
los Det
argentinos NC
Juan_Gelman NP
, Punt
Adolfo_Colombé NP
y Conj
Norberto_Galusso NP
, Punt
la Det
salvadoreña NC
Claribel_Alegría NP
, Punt
la Det
chilena NC
Stela_Díaz_Varín NP
y Conj
el Det
mexicano NC
Eraclio_Zepeda NP
. Fin
Además Adv
, Punt
en Prep
la Det
feria NC
serán V
homenajeados NC
los Det
escritores NC
cubanos Adj
Dulce_María_Loynaz NP
, Punt
ganadora Adj
del Prep
premio NC
" Punt
Cervantes NC
" Punt
de Prep
literatura NC
en Prep
1992 Num
, Punt
Eliseo_Diego NP
, Punt
premiado Adj
con Prep
el Det
galardón NC
" Punt
Juan_Rulfo NP
" Punt
1993 Num
, Punt
y Conj
el Det
recién Adv
fallecido V
Severo_Sarduy NP
. Fin
La Det
feria NC
es V
convocada Adj
cada Det
dos Det
años NC
y Conj
en Prep
su Det
programación NC
incluye V
la Pron
entrega V
del Prep
Premio_Nacional_de_Literatura NP
y Conj
el Det
de Prep
la Det
Crítica NP
, Punt
que Pron
proclama NC
los Det
diez NC
mejores Adj
títulos NC
publicados Adj
el Det
año NC
pasado Adj
. Fin
Los Det
cancilleres NC
de Prep
Centroamérica NP
y Conj
la Det
Comunidad_Económica_del_Caribe NP
( Fin
CARICOM NP
) Fin
celebrarán V
su Det
tercera Adj
reunión NC
durante Prep
la Det
primera Adj
semana NC
de Prep
marzo NC
, Punt
en Prep
Costa_Rica NP
, Punt
para Prep
analizar V
asuntos NC
comunes Adj
a Prep
ambas Det
regiones NC
y Conj
la Det
comercialización NC
bananera Adj
con Prep
la Det
Unión_Europea NP
( Fin
UE NP
) Fin
. Fin
El Det
canciller NC
costarricense Adj
, Punt
Bernd_Niehaus NP
, Punt
dijo V
que Conj
en Prep
esta Det
reunión NC
continuará V
el Det
análisis NC
conjunto NC
de Prep
diversas Det
cuestiones NC
, Punt
como Conj
en Prep
las Det
dos Det
anteriores Adj
reuniones NC
, Punt
celebradas Adj
en Prep
San_Pedro_Sula NP
( Fin
Honduras NC
) Fin
, Punt
en Prep
1992 Num
, Punt
y Conj
en Prep
Kingston NP
, Punt
la Det
capital NC
jamaicana Adj
, Punt
el Det
año NC
pasado Adj
. Fin
Niehaus NP
consideró V
que Conj
la Det
comercialización NC
bananera Adj
no Adv
estará V
ausente Adj
de Prep
esta Det
reunión NC
, Punt
por Prep
la Det
importancia NC
que Pron
reviste V
para Prep
la Det
mayoría NC
de Prep
naciones NC
centroamericanas Adj
y Conj
caribeñas Adj
, Punt
muchas Pron
de Prep
las Det
cuales Pron
dependen V
en_gran_medida Adv
de Prep
la Det
exportación NC
de Prep
esta Det
fruta NC
. Fin
Las Det
restricciones NC
impuestas Adj
por Prep
la Det
UE NP
a Prep
la Det
importación NC
de Prep
esta Det
fruta NC
desde Prep
julio NC
pasado Adj
y Conj
que Pron
afectan V
a Prep
América_Latina NP
favorecen V
a Prep
varios Pron
de Prep
los Det
países NC
del Prep
CARICOM NP
, Punt
que Pron
fueron V
colonias NC
europeas Adj
. Fin
El Det
canciller NC
dijo V
que Conj
se Pron
debe V
buscar V
un Det
acuerdo NC
sobre Prep
comercialización NC
del Prep
banano NC
con Prep
la Det
UE NP
que Pron
no Adv
afecte V
a Prep
la Det
región NC
caribeña Adj
ni Conj
a Prep
los Det
productores NC
de Prep
Latinoamérica NP
, Punt
quienes Pron
han VAux
visto V
reducir V
sus Det
exportaciones NC
de Prep
la Det
fruta NC
de Prep
2,5 Num
a Prep
2 Num
millones NC
de Prep
toneladas NC
por Prep
las Det
barreras NC
europeas Adj
. Fin
Los Det
países NC
productores Adj
de Prep
café NC
suave Adj
de Prep
América_Latina NP
se Pron
reunirán V
mañana NC
viernes NC
en Prep
Guatemala NP
para Prep
analizar V
los Det
primeros Adj
resultados NC
del Prep
plan NC
de Prep
retención NC
y Conj
el Det
comportamiento NC
de Prep
las Det
exportaciones NC
del Prep
grano NC
en Prep
el Det
mercado NC
internacional Adj
. Fin
La Det
Asociación_Nacional_de_Café NP
( Fin
ANACAFE NP
) Fin
de Prep
Guatemala NP
indicó V
que Conj
la Det
reunión NC
, Punt
a Prep
la Det
que Pron
asistirán V
Centroamérica NP
y Conj
Colombia NP
, Punt
servirá V
también Adv
para Prep
analizar V
el Det
Convenio_Internacional_de_Café NP
y Conj
para Prep
revisar V
los Det
avances NC
de Prep
la Det
creación NC
de Prep
la Det
Asociación_de_Países_Productores_de_Café NP
( Fin
APC NP
) Fin
. Fin
Los Det
representantes NC
evaluarán V
el Det
impacto NC
que Conj
ha VAux
tenido V
el Det
plan NC
de Prep
retención NC
en Prep
el Det
precio NC
del Prep
grano NC
, Punt
que Pron
entró V
en Prep
vigor NC
el Det
1_de_octubre Data
pasado Adj
, Punt
y Conj
cómo Pron
ha VAux
afectado V
a Prep
la Det
posición NC
de Prep
Brasil NP
, Punt
que Pron
aún Adv
no Adv
lo Pron
acepta V
completamente Adv
. Fin
De Prep
acuerdo NC
con Prep
ANACAFE NP
, Punt
los Det
seis Det
países NC
han VAux
retenido V
el Det
20 Num
por Prep
ciento NC
de Prep
las Det
exportaciones NC
, Punt
lo Det
que Pron
ha VAux
permitido V
que Conj
el Det
quintal NC
( Fin
de Prep
50 Num
kilos NC
) Fin
, Punt
puesto NC
en Prep
Nueva_York NP
, Punt
aumente V
de Prep
60 Num
a Prep
75 Num
dólares NC
. Fin
Con_relación_al Prep
acuerdo NC
de Prep
creación NC
de Prep
la Det
asociación NC
, Punt
suscrito Adj
en Prep
septiembre NC
pasado Adj
en Prep
Brasilia NP
y Conj
que Pron
representaría V
a Prep
más Adv
del Prep
50 Num
por Prep
ciento NC
de Prep
los Det
exportadores NC
de Prep
café NC
a_nivel Adv
mundial Adj
, Punt
los Det
países NC
signatarios Adj
informarán V
sobre Prep
el Det
procedimiento NC
de Prep
ratificación NC
. Fin
Resultados NC
de Prep
la Det
novena Adj
jornada NC
y Conj
clasificaciones NC
de Prep
los Det
Grupos_A NP
y Conj
B_de_la_Liga_Europea NP
masculina Adj
de Prep
baloncesto NC
: Punt
- Punt
Resultados NC
: Punt
-- Punt
Grupo_A NP
: Punt
Barcelona NP
( Fin
ESP NP
) Fin
77 Num
- Punt
Benetton_Treviso NP
( Fin
ITA Adj
) Fin
68 Num
Bayer_Leverkusen NP
( Fin
ALE NC
) Fin
87 Num
- Punt
Limoges NP
( Fin
output_test1.txt
tertulias NC
Según unknown
tenido V
Fiscalía_General unknown
fuente NC
PJ_PG_PP_PF_PC_PTOS NP
PJ_PG_PP_PF_PC_PTOS NP
magistrado NC
magistrado NC
invitados NC
depositó unknown
ciudad NC
primer Adj
YUG NP
pobreza NC
celebradas Adj
según unknown
a_pesar_de Prep
viajar V
suave Adj
vez NC
quienes Pron
0 Num
masculina Adj
encuentros NC
solución unknown
665 Num
negociación unknown
empresario NC
feria NC
feria NC
feria NC
feria NC
feria NC
seis Det
cómo unknown
alcanzando V
estaba V
región unknown
718 Num
exportadores NC
714 Num
711 Num
710 Num
BARCELONISTAS_SALVARON_DIFICIL_ESCOLLO NP
ausente Adj
tratar V
Benetton_Treviso NP
francés unknown
imputadas Adj
ilegales Adj
dictó unknown
-- Punt
-- Punt
-- Punt
reducir V
además_de unknown
a_nivel Adv
afirmó unknown
recabados V
meses NC
mundial Adj
peores Adj
suscrito V
pueblos NC
tenía unknown
BEL NC
balneario Adj
cuentas NC
cuentas NC
cuentas NC
señalaron unknown
Pablo_Pacheco NP
Grecia NP
reviste V
abogado V
abogado V
comprado V
importación unknown
sentencia NC
sentencia NC
Latinoamérica unknown
Chiapas NP
Francia NP
Francia NP
Francia NP
Francia NP
Gaspar_Wittgren NP
escándalo unknown
para_que Conj
para_que Conj
para_que Conj
Butros_Gali NP
entrega V
sus Det
sus Det
sus Det
sus Det
sus Det
Caribe Adj
capital NC
; Punt
EP_Estambul-Panathinaikos_Cibona_Zagreb-Joventut_Benfica_Lisboa-Clear_Cantú_Pau_Orthez-Buckler_Bolonia unknown
títulos unknown
Grupo_A NP
Grupo_A NP
reuniones NC
77-68 Num
Brasilia NP
Chipre NP
Asociación_de_Países_Productores_de_Café unknown
acuerdo NC
acuerdo NC
acuerdo NC
GRE NP
GRE NP
GRE NP
sucedía unknown
mes NC
mes NC
Thomas_K._Equels NP
dedicada Adj
norteamericanas Adj
viaje NC
viaje NC
Adolfo_Colombé unknown
congelar V
38 Num
Clark NP
A_través_de unknown
30 Num
precio NC
Policía_Federal unknown
barreras NC
44 Num
44 Num
oficial Adj
acción unknown
645 Num
incremento NC
clima NC
ING NP
julio NC
importancia NC
apropió unknown
ONU_para_Chipre NP
Además unknown
Stela_Díaz_Varín unknown
unos Pron
unos Pron
semana NC
semana NC
2,5 Num
otros Det
presidenta NC
Ecuador NC
presidente NC
presidente NC
presidente NC
presidente NC
presidente NC
presidente NC
presidente NC
Diez Det
internacional Adj
internacional Adj
internacional Adj
Europa NP
Europa NP
Bayer_Leverkusen NP
Bayer_Leverkusen NP
Instituto_Cubano_del_Libro NP
espectadores NC
activades NC
conocer V
europeas NC
europeas NC
francesa Adj
francesa Adj
hacían unknown
informarán unknown
Iacopini NP
6 Num
6 Num
6 Num
6 Num
6 Num
galardón unknown
José_Salgar unknown
Unión_Europea unknown
zona NC
Pau_Orthez NP
Pau_Orthez NP
programación unknown
Premio_Nacional_de_Literatura NP
asistirá unknown
mayoría unknown
sublevado V
novena Adj
novena Adj
especialista NC
servirá unknown
destacable Adj
retención unknown
Cervantes NC
Vianini NP
94 Num
tribunal NC
tribunal NC
1993 Num
1992 Num
1992 Num
40 Num
40 Num
40 Num
autónomo unknown
servido V
ALE NC
mi Det
mi Det
temas NC
editoriales NC
Buckler_Bolonia NP
Buckler_Bolonia NP
del Prep
del Prep
del Prep
del Prep
del Prep
del Prep
del Prep
del Prep
del Prep
del Prep
del Prep
del Prep
del Prep
del Prep
del Prep
del Prep
del Prep
del Prep
del Prep
del Prep
del Prep
del Prep
del Prep
del Prep
permita V
Colombia NP
política unknown
problemas NC
tampoco Adv
vigor NC
creación unknown
558 Num
La NP
La NP
La NP
La NP
prisión unknown
financieras Adj
Comunidad_Económica_del_Caribe unknown
propicio Adj
mercado NC
Collor NP
Collor NP
Collor NP
Collor NP
Collor NP
proceso NC
proceso NC
proceso NC
proceso NC
proceso NC
comercialización unknown
lograr V
Malinas NP
fuentes NC
fuentes NC
impacto NC
recién unknown
representaría unknown
Dirección_de_Recuperación_Patrimonial_de_la_Contraloría_General_de_la_Nación unknown
Manuel_Antonio_Noriega NP
ene NC
Yo NP
asistirán unknown
1 Num
presunta Adj
Alemania NP
acordadas Adj
años unknown
sin Prep
Bayer_Leverkusen-Barcelona_Benetton_Treviso-Racing_Malinas_Limoges-Guilford_Kings_Olympiakos-Real_Madrid NP
iberoamericana Adj
y Conj
y Conj
y Conj
y Conj
y Conj
y Conj
y Conj
y Conj
y Conj
y Conj
y Conj
y Conj
y Conj
y Conj
y Conj
y Conj
y Conj
y Conj
y Conj
y Conj
y Conj
y Conj
y Conj
y Conj
y Conj
y Conj
y Conj
y Conj
y Conj
y Conj
y Conj
y Conj
y Conj
y Conj
y Conj
y Conj
y Conj
y Conj
y Conj
y Conj
y Conj
y Conj
y Conj
y Conj
y Conj
y Conj
y Conj
y Conj
y Conj
y Conj
y Conj
y Conj
4.850 Num
culpables Adj
Gran_Bretaña unknown
rechaza V
Destacó unknown
UE NP
UE NP
UE NP
Pittis NP
director NC
sometido V
hombre NC
brasileño unknown
especializada Adj
las Det
las Det
las Det
las Det
las Det
las Det
las Det
las Det
las Det
las Det
las Det
las Det
las Det
las Det
las Det
las Det
a Prep
a Prep
a Prep
a Prep
a Prep
a Prep
a Prep
a Prep
a Prep
a Prep
a Prep
a Prep
a Prep
a Prep
a Prep
a Prep
a Prep
a Prep
a Prep
a Prep
a Prep
a Prep
a Prep
a Prep
a Prep
a Prep
a Prep
a Prep
a Prep
a Prep
a Prep
a Prep
a Prep
a Prep
trata V
muertos Adj
canciller NC
canciller NC
su Det
su Det
su Det
su Det
su Det
su Det
su Det
su Det
su Det
su Det
su Det
hasta Prep
hasta Prep
primera Adj
primera Adj
primera Adj
entró unknown
logros NC
Incidencias NC
686 Num
avances NC
680 Num
intercomunitarias Adj
682 Num
También unknown
sucesor NC
Próxima unknown
connivencia NC
dimitió unknown
implantada V
producen V
Bernd_Niehaus NP
España unknown
mejores Adj
miembros NC
Eraclio_Zepeda NP
1_de_octubre Data
ronda NC
22 Num
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
la Det
sospechosas Adj
lo Pron
lo Pron
lo Pron
caribeña unknown
fue V
fue V
fue V
fue V
fue V
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
, Punt
As you can see, every line corresponds to: word+"\t"+tag
Here is my code:
with open("output_test1.txt", "r") as a, open("gold_standard_1.txt", "r") as b:
dataA=a.readlines()
dataB=b.readlines()
aciertos = 0;
for lineaA in dataA:
lineaA.decode('latin_1').encode('utf-8')
sintagmaA = lineaA.split('\t')
for lineaB in dataB:
lineaB.decode('latin_1').encode('utf-8')
sintagmaB = lineaB.split('\t')
print sintagmaB[0]
print sintagmaA[0]
if(sintagmaA[0] == sintagmaB[0] and sintagmaA[1]== sintagmaB[1]):
aciertos+=1;
break
And if I try to print aciertos, at the end, the value is always 0...but there
are matches!!! How can I compare the documents in the right form?
Answer: Your current technique is quite inefficient as you iterate over the second
file _for each line_ in the first.
Try the code below.
set_a, set_b = set(), set()
with open('a', 'r') as a, open('b', 'r') as b:
for line in a:
set_a.add(line)
for l in b:
set_b.add(line)
print set_a & set_b
What this does is builds two sets, each with lines from file `a` abd `b`. Then
it does an intersection `set_a & set_b` to get the lines that are common to
both files.
Replace `a` and `b` with your file names and do any additional encode / decode
on the `line` in each for loop before adding it to the set. If not, the code
will do an exact match of the lines (including leading / trailing
whitespaces).
|
Python 3.4.3 subprocess.Popen get output of command without piping?
Question: I am trying to assign the output of a command to a variable without the
command thinking that it is being piped. The reason for this is that the
command in question gives unformatted text as output if it is being piped, but
it gives color formatted text if it is being run from the terminal. I need to
get this color formatted text.
So far I've tried a few things. I've tried Popen like so:
output = subprocess.Popen(command, stdout=subprocess.PIPE)
output = output.communicate()[0]
output = output.decode()
print(output)
This will let me print the output, but it gives me the unformatted output that
I get when the command is piped. That makes sense, as I'm piping it here in
the Python code. But I am curious if there is a way to assign the output of
this command, directly to a variable, without the command running the piped
version of itself.
I have also tried the following version that relies on check_output instead:
output = subprocess.check_output(command)
output = output.decode()
print(output)
And again I get the same unformatted output that the command returns when the
command is piped.
Is there a way to get the formatted output, the output the command would
normally give from the terminal, when it is not being piped?
Answer: Using [pexpect](https://pexpect.readthedocs.org/en/latest/install.html):
2.py:
import sys
if sys.stdout.isatty():
print('hello')
else:
print('goodbye')
subprocess:
import subprocess
p = subprocess.Popen(
['python3.4', '2.py'],
stdout=subprocess.PIPE
)
print(p.stdout.read())
--output:--
goodbye
pexpect:
import pexpect
child = pexpect.spawn('python3.4 2.py')
child.expect(pexpect.EOF)
print(child.before) #Print all the output before the expectation.
--output:--
hello
Here it is with `grep --colour=auto`:
import subprocess
p = subprocess.Popen(
['grep', '--colour=auto', 'hello', 'data.txt'],
stdout=subprocess.PIPE
)
print(p.stdout.read())
import pexpect
child = pexpect.spawn('grep --colour=auto hello data.txt')
child.expect(pexpect.EOF)
print(child.before)
--output:--
b'hello world\n'
b'\x1b[01;31mhello\x1b[00m world\r\n'
|
Using python openpyxl, how to skip first several lines?
Question: I am using openpyxl, I tried to read from the fifth line for some files. The
files' first four lines are the header. then the main content has a different
format than the header. And I tried the method:
import openpyxl
file_name="xxx.xlsx"
wb = openpyxl.load_workbook(filename=file_name, use_iterators = True)
first_sheet = workbook.get_sheet_names()[0]
ws = workbook.get_sheet_by_name(first_sheet)
for index, row in enumerate(ws.iter_rows()):
if start < index < stop:
for c in row:
print c.value
It will always have the error:
IndexError: list index out of range
If I delete the first four lines, the data can be read into python easily. But
I have hundreds of such files, each file has a header for four lines. It will
take way much time to delete all the headers from the files. How to skip first
several lines when reading using openpyxl correctly?
Answer: You can pass a range into `ws.iter_rows('A4:Z256')` but you're probably better
off using `ws.get_squared_range(1, 5,)`
|
Caesar Cipher program was working but now isn't(help please) - Python 3
Question: I'm writing a Caesar Cipher code for a part of a controlled assessment. I
built a fully functioning program and I thought I had it sussed but after
changing a few things around I went to check back and everything has gone
wrong!
The code's quite untidy but I'm getting a bit sick of coding this now and have
taken to the internet to get someone else's view.
Code:
answer ="C"
while answer == "C":
lettersList=['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','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']
def menu():
userChoice=input("Would you like to encrypt or decrypt a message? E or D.\n").lower()
while userChoice != "e" and userChoice != "d":
print("Invalid.")
userChoice=input("Would you like to encrypt or decrypt a message? E or D.\n").lower()
print("\n")
return userChoice
def getPlaintext():
plaintext= input("Please enter the message you would like encrypted/decrypted\n").lower()
while plaintext.isalpha() == False:
print("Invalid")
plaintext=input("Please enter the message you would like encrypted/decrypted\n").lower()
print("\n")
return plaintext
def getKey():
key=int(input("Please enter a key. 1-26\n"))
while key > 26 or key < 1:
print("Invalid.")
key=int(input("Please enter a key. 1-26\n"))
print("\n")
return key
def encryptText(plaintext,key):
characterNumber = 0
newMessage = ""
for characters in plaintext:
character = plaintext[characterNumber]
characterPosition = lettersList.index(character)
newPosition=character+key
newLetter = lettersList[newPosition]
newMessage = (newMessage+newLetter)
characterNumber= characterNumber+1
print(newMessage)
def decryptText(plaintext,key):
characterNumber = 0
newMessage = ""
for characters in plaintext:
character = plaintext[characterNumber]
characterPosition = lettersList.index(character)
print(characterPosition)
newPosition=characterPosition-key
newLetter = lettersList[newPosition]
newMessage = (newMessage+newLetter)
characterNumber= characterNumber+1
newMessage = (newMessage.lower())
print(newMessage)
userChoice=menu()
plaintext=getPlaintext()
key=getKey()
if userChoice == "e":
encryptText(plaintext,key)
elif userChoice == "d":
decryptText(plaintext,key)
print(newMessage)
Answer: In decypryptText, newPosition can be negative. You should wrap around the
whole alphabet in this case. The best way to do that is to use the % operator:
newPosition = (characterPosition - key) % len(lettersList)
By the way, using this in encryptText too lets you make lettersList only one
copy of the alphabet, instead of the two copies you use.
There are other things that can be polished in this code, but they are not as
important as this one.
Edit: if you want it capitalized for decryptText, you can make decryptText
just return newMessage.upper(). In the same way, you can make encryptText
return newMessage.lower().
|
Python Pandas - Main DataFrame, want to drop all columns in smaller DataFrame
Question: I have a DataFrame ('main') that has about 300 columns. I created a smaller
DataFrame ('public') and have been working on this.
I now want to delete the columns contained within 'public' from the larger
DataFrame ('main').
I've tried the following instructions:
<http://pandas.pydata.org/pandas-
docs/dev/generated/pandas.DataFrame.drop.html>
[Python Pandas - Deleting multiple series from a data frame in one
command](http://stackoverflow.com/questions/14363640/python-pandas-deleting-
multiple-series-from-a-data-frame-in-one-command)
without any success, along with various other statements that have been
unsuccessful.
The columns that make up 'public' are not consecutive - i.e. they are taken
from various points in the larger DataFrame 'main'. All of the columns have
the same Index. [Not sure if this is important, but 'public' was created using
the 'join' function].
Yes, I'm being lazy - I don't want to have to type out the names of every
column! I'm hoping there's a way to use the DataFrame 'public' in a statement
that will allow deletion of these columns en masse. If anyone has any
suggestions and/or guidance I'd be most grateful.
(Have Python 2.7 and am using Pandas, numpy, math, pylab etc.)
Thanks in advance.
Answer: Ignore my question - Murphy's Law prevails and I've just solved it.
I was using the statement from the stackoverflow question mentioned below:
df.drop(df.columns[1:], axis=1)
and this was not working. I have instead used
df = df.drop(df2, axis=1)
and this worked (df = main, df2 = public). Simple really once you don't
overthink it.
|
Headers with Python List
Question: Python newbie. I have csv data the looks like the following:
Record Name Cur e12mo e24mo e48mo state
3928 Joes 2000 200 400 0 CA,GA
1 Toms 19 1 2 0 AR,KS
1747 Mine 60 5 10 0 AR,CT
5023 Yours 5 12 24 0 FL
7041 Theirs 10 2 4 0 FL
Am entering code from tutorial as follows:
import numpy as np
import csv as csv
readdata = csv.reader(open('c:\MyData\BYLCsv.csv'))
for row in readdata:
print(row)
data = []
for row in readdata:
data.append(row)
for row in data:
print(row)
Header = data[0]
data.pop(0)
Code bombs on the "Header = data[0]" statement. Everything runs up to there.
Answer: In your first loop, you read the whole file, the file pointer is not reset
afterwards:
import numpy as np
import csv as csv
with open('c:\MyData\BYLCsv.csv') as data:
readdata = csv.reader(data)
header = next(readdata)
data = list(readdata)
print(header)
for row in data:
print(row)
|
US Census API - Get The Population of Every City in a State Using Python
Question: I'm having an issue getting the population of every city in a specific state.
I do get the population of cities but if I sum the population in every city I
don't get the same number as the population of the state.
I got my [API Key](http://api.census.gov/data/key_signup.html) used the
[P0010001 variable](http://api.census.gov/data/2010/sf1/variables.html) for
total population used the FIPS 25 for the state of Massachusetts and requested
the population by the [geography level
"place"](http://api.census.gov/data/2010/sf1/geography.html) which I
understand it to mean city.
Here is the Python 3 code I used:
import urllib.request
import ast
class Census:
def __init__(self, key):
self.key = key
def get(self, fields, geo, year=2010, dataset='sf1'):
fields = [','.join(fields)]
base_url = 'http://api.census.gov/data/%s/%s?key=%s&get=' % (str(year), dataset, self.key)
query = fields
for item in geo:
query.append(item)
add_url = '&'.join(query)
url = base_url + add_url
print(url)
req = urllib.request.Request(url)
response = urllib.request.urlopen(req)
return response.read()
c = Census('<mykey>')
state = c.get(['P0010001'], ['for=state:25'])
# url: http://api.census.gov/data/2010/sf1?key=<mykey>&get=P0010001&for=state:25
county = c.get(['P0010001'], ['in=state:25', 'for=county:*'])
# url: http://api.census.gov/data/2010/sf1?key=<mykey>&get=P0010001&in=state:25&for=county:*
city = c.get(['P0010001'], ['in=state:25', 'for=place:*'])
# url: http://api.census.gov/data/2010/sf1?key=<mykey>&get=P0010001&in=state:25&for=place:*
# Cast result to list type
state_result = ast.literal_eval(state.decode('utf8'))
county_result = ast.literal_eval(county.decode('utf8'))
city_result = ast.literal_eval(city.decode('utf8'))
def count_pop_county():
count = 0
for item in county_result[1:]:
count += int(item[0])
return count
def count_pop_city():
count = 0
for item in city_result[1:]:
count += int(item[0])
return count
**And here are the results:**
print(state)
# b'[["P0010001","state"],\n["6547629","25"]]'
print('Total state population:', state_result[1][0])
# Total state population: 6547629
print('Population in all counties', count_pop_county())
# Population in all counties 6547629
print('Population in all cities', count_pop_city())
# Population in all cities 4615402
I'm reasonable sure that 'place' is the city e.g.
# Get population of Boston (FIPS is 07000)
boston = c.get(['P0010001'], ['in=state:25', 'for=place:07000'])
print(boston)
# b'[["P0010001","state","place"],\n["617594","25","07000"]]'
What am I doing wrong or misunderstanding? **Why is the sum of populations by
place not equal to the population of the state?**
[List of example API calls](http://api.census.gov/data/2010/sf1/geo.html)
Answer: _if I sum the population in every city I don't get the same number as the
population of the state._
That's because not everybody lives **in a city** \-- there are rural
"unincorporated areas" in many counties that are not part of any city, and,
people do live there.
So, this is not a programming problem!-)
|
Unable to start AMS Acomba Connector on Windows
Question: I am trying to get a python service to run under Windows 7 however I am unable
to start it.
I have started by installing the service using
c:\amsconnector>amsconnector.py --username domain\admin --password ************ install
Installing service AMS Acomba Connector
Service installed
After that, I run
c:\amsconnector>amsconnector.py start
Starting service AMS Acomba Connector
When I check the running services list, I notice that the service is not
running and when checking the event log, I am presented with this stacktrace
Python could not import the service's module
Traceback (most recent call last):
File "C:\amsconnector\amsconnector.py", line 343, in <module>
win32serviceutil.HandleCommandLine(AMSConnectorService)
File "C:\Python27\lib\site-packages\win32\lib\win32serviceutil.py", line 521, in HandleCommandLine
usage()
File "C:\Python27\lib\site-packages\win32\lib\win32serviceutil.py", line 505, in usage
sys.exit(1)
SystemExit: 1
%2: %3
The line 343 of amsconnector.py looks like this
if True or __name__ == '__main__':
win32serviceutil.HandleCommandLine(AMSConnectorService)
After checking out the source code of win32serviceutil.py, it appears that the
service is just printing out the win32service usage dialog instead of actually
running the python class. I am completely confused!
Answer: Thanks roeland!
I was able to fix the issue by simply removing the "True or" part of the last
line leaving it like this:
if True or __name__ == '__main__':
win32serviceutil.HandleCommandLine(AMSConnectorService)
|
How to convert this json string to dict?
Question: After executing the following code:
import json
a = '{"excludeTypes":"*.exe;~\\$*.*"}'
json.loads(a)
I get:
> Traceback (most recent call last): File "", line 1, in File
> "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/json/**init**.py",
> line 338, in loads return _default_decoder.decode(s) File
> "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/json/decoder.py",
> line 365, in decode obj, end = self.raw_decode(s, idx=_w(s, 0).end()) File
> "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/json/decoder.py",
> line 381, in raw_decode obj, end = self.scan_once(s, idx) ValueError:
> Expecting property name: line 1 column 2 (char 1)
So how can I convert 'a' to dict. Please note that the string is already in
'a' and I cannot add 'r' in front of it. Ideally, the string should have been
`{"excludeTypes":"*.exe;~\\\\$*.*"}`
Also, the following code doesn't work:
import json
a = '{"excludeTypes":"*.exe;~\\$*.*"}'
b = repr(a)
json.loads(b)
Answer:
import ast
d = ast.literal_eval(a)
|
Why am I getting "UnicodeEncodeError: 'charmap' codec can't encode character" error message
Question: I encountered a problem with Python script I wrote while running in a Windows
CMD window, and boiled the essence of the problem down to the following
[SSCCE](http://sscce.org/):
**The Python script (x.py)**
import sys
in_file = open (sys.argv[1], 'rt')
for line in in_file:
line = line.rstrip ('\n')
print ('line="%s"' % (line))
in_file.close ()
**The input data file (x.txt)**
Line 1
Line 2 “text”
Line 3
**The command line invocation**
python x.py x.txt
**The error output**
C:\junk>python x.py x.txt
line="Line 1"
Traceback (most recent call last):
File "x.py", line 7, in <module>
print ('line="%s"' % (line))
File "C:\Program Files (x86)\Python34\lib\encodings\cp862.py", line 19, in encode
return codecs.charmap_encode(input,self.errors,encoding_map)[0]
UnicodeEncodeError: 'charmap' codec can't encode character '\u201c' in position 13: character maps to <undefined>
C:\junk>
It seems to be failing on the second input record ("Line 2"). What am I doing
wrong?
Answer: The answer turned out to be a Windows codepage issue.
The second input line uses the ANSI typographical characters 0x93 (147) and
0x94 (148), corresponding to the left and right quotation marks, respectively.
Although the input file was meant to be an ASCII file (i.e., characters < 128
decimal), word processors, in contrast to text editors, will often insert
these specialized characters.
Python read it well enough, but threw an exception when trying to print it to
the console window. As the error output shows, the error message emanates from
lib\encodings\cp862.py, which corresponds to [code page
862](http://en.wikipedia.org/wiki/Code_page_862), MS_DOS's code page for
Hebrew. Windows attempts to convert the ANSI character 0x93 (147) to the
Unicode U+201C ("LEFT DOUBLE QUOTATION MARK"), which Python's default encoding
cannot support.
Executing the [CHCP (Change Codepage)
command](https://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-
us/chcp.mspx?mfr=true) gives:
C:\junk>chcp
Active code page: 862
C:\junk>
Changing the CMD window's codepage to CP 1252 ("Latin-1") solves the problem:
C:\junk>chcp 1252
Active code page: 1252
C:\junk>python x.py x.txt
line="Line 1"
line="Line 2 “text”"
line="Line 3"
C:\junk>
|
Psycopg ppygis select query
Question: I'm trying to setup a basic working postgis setup with python ppygis package.
>>> import psycopg2
>>> import ppygis
>>> connection = psycopg2.connect(database='spre', user='postgres')
>>> cursor = connection.cursor()
>>> cursor.execute('CREATE TABLE test (geometry GEOMETRY)')
>>> cursor.execute('INSERT INTO test VALUES(%s)', (ppygis.Point(1.0, 2.0),))
>>> cursor.execute('SELECT * from test')
>>> point = cursor.fetchone()[0]
>>> print point
0101000000000000000000F03F0000000000000040
>>>
I should have got a python object with separate X and Y coordinate. Something
like
>>> Point(X: 1.0, Y: 2.0)
What am I doing wrong?
Answer: You are doing nothing wrong. Following [the same steps as the PPyGIS basic
example](http://www.fabianowski.eu/projects/ppygis/usage.html#basic-usage), I
get the same [hex-encoded EWKB](https://en.wikipedia.org/wiki/Well-
known_binary) as shown in the question (010100...), which is normally
expected. Perhaps this worked with an older version of PPyGIS / Psycopg? It
doesn't today.
The package does not appear to properly register itself as an adapter for
PostGIS types, so my advice is to not use the package. Besides, you don't need
additional packages to use PostGIS from Psycopg2.
* * *
Here is the normal approach to read/write points, without any extra packages:
# Assuming PostGIS 2.x, use a typmod
cursor.execute('CREATE TEMP TABLE test (geom geometry(PointZ,4326));')
# Longyearbyen, 78.22°N 15.65°E, altitude 10 m
cursor.execute('''\
INSERT INTO test (geom)
VALUES(ST_SetSRID(ST_MakePoint(%s, %s, %s), 4326));
''', (15.65, 78.22, 10.0))
cursor.execute('''\
SELECT ST_Y(geom) AS latitude, ST_X(geom) AS longitude, ST_Z(geom) AS altitude
FROM test;
''')
print(cursor.fetchone()) # (78.22, 15.65, 10.0)
cursor.execute('SELECT ST_AsText(geom) FROM test;')
print(cursor.fetchone()[0]) # POINT Z (15.65 78.22 10)
cursor.execute('SELECT ST_AsLatLonText(geom) FROM test;')
print(cursor.fetchone()[0]) # 78°13'12.000"N 15°39'0.000"E
If you want a geometry object on the client-side to do more work with the
actual geometry, consider using Shapely, which can be interfaced using WKB
data:
from shapely.wkb import loads
cursor.execute('SELECT geom FROM test;')
pt = loads(cursor.fetchone()[0], hex=True)
print(pt) # POINT Z (15.65 78.22 10)
|
Django finds all static files except one - 404
Question: I had my static files working correctly until I tried to add this library
<https://github.com/ierror/django-js-reverse>
I followed the instructions from the page, but Django still can't find the new
resource.
from settings.py
STATIC_ROOT = 'staticfiles'
STATIC_URL = '/static/'
STATICFILES_DIRS = (
os.path.join(BASE_DIR, 'static/'),
)
INSTALLED_APPS = (
'django.contrib.admin',
'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.messages',
'django.contrib.staticfiles',
'django_js_reverse',
...,
)
in my template
<script src="{% static 'django_js_reverse/js/reverse.js' %}"></script>
my directory structure looks like this
staticfiles/
admin/
dist/
django_js_reverse/
js/
reverse.js
After running
python manage.py collectstatic
python manage.py runserver
I also tried to run the following according to the library instructions, but
no luck
./manage.py collectstatic_js_reverse
Here's the output from runserver when I try to load the page.
[08/Mar/2015 19:12:33] "GET /static/custom.css HTTP/1.1" 304 0
[08/Mar/2015 19:12:33] "GET /static/dist/css/bootstrap.min.css HTTP/1.1" 304 0
[08/Mar/2015 19:12:33] "GET /static/django_js_reverse/js/reverse.js HTTP/1.1" 404 1697
[08/Mar/2015 19:12:33] "GET /static/dist/js/bootstrap.min.js HTTP/1.1" 304 0
[08/Mar/2015 19:12:33] "GET /static/csrf.js HTTP/1.1" 304 0
[08/Mar/2015 19:12:33] "GET /static/custom.js HTTP/1.1" 304 0
I can't figure out where the issue is. The static files settings are obviously
set up correctly because all the other files are being loaded fine. I must be
missing something obvious. Any help would be appreciated\
UPDATE
I tried moving the reverse.js file to dist/ but it still returns a 404.
The permissions on all the files are the same
ls -la staticfiles/dist/js
-rw-r--r-- 1 adam staff 67155 Mar 8 15:06 bootstrap.js
-rw-r--r-- 1 adam staff 35601 Mar 8 15:06 bootstrap.min.js
-rw-r--r-- 1 adam staff 484 Mar 8 15:06 npm.js
-rw-r--r-- 1 adam staff 3258 Mar 10 10:31 reverse.js
Answer: Got same problem and tried everything. Url to js file seems legit but it isn't
(with Django 1.9 at least).
I've changed it from
<script src="{% static 'django_js_reverse/js/reverse.js' %}"></script>
to
<script src="{% url 'js_reverse' %}"></script>
And you need this url pattern in urls.py for this solution
# import view
from django_js_reverse.views import urls_js
# and add this in url patterns
url(r'^jsreverse/$', 'django_js_reverse.views.urls_js', name='js_reverse'),
And now it's working without any problem . Hope this will help somebody.
|
Equivalent Python code for the following Java http get requests
Question: I am trying to convert the following Java code to Python. Not sure what I am
doing wrong, but I end up with an internal server error 500 with python.
Is the "body" in `httplib.httpConnection` method equivalent to Java
`httpentity`? Any other thoughts on what could be wrong? The input information
I collect is correct for sure.
Any help will be really appreciated. I have tried several things, but end up
with the same internal server error.
Java Code:
HttpEntity reqEntitiy = new StringEntity("loginTicket="+ticket);
HttpRequestBase request = reMethod.getRequest(uri, reqEntitiy);
request.addHeader("ticket", ticket);
HttpResponse response = httpclient.execute(request);
HttpEntity responseEntity = response.getEntity();
StatusLine responseStatus = response.getStatusLine();
Python code:
url = serverURL + "resources/slmservices/templates/"+templateId+"/options"
#Create the request
ticket = ticket.replace("'",'"')
headers = {"ticket":ticket}
print "ticket",ticket
reqEntity = "loginTicket="+ticket
body = "loginTicket="+ticket
url2 = urlparse.urlparse(serverURL)
h1 = httplib.HTTPConnection(url2.hostname,8580)
print "h1",h1
url3 = urlparse.urlparse(url)
print "url path",url3.path
ubody = {"loginTicket":ticket}
data = urllib.urlencode(ubody)
conn = h1.request("GET",url3.path,data,headers)
#conn = h1.request("GET",url3.path)
response = h1.getresponse()
lines = response.read()
print "response.status",response.status
print "response.reason",response.reason
Answer: You don't need to go this low level. Using `urllib2` instead:
import urllib2
from urllib import urlencode
url = "{}resources/slmservices/templates/{}/options".format(
serverURL, templateId)
headers = {"ticket": ticket}
params = {"loginTicket": ticket}
url = '{}?{}'.format(url, urlencode(params))
request = urllib2.Request(url, headers=headers)
response = urllib2.urlopen(request)
print 'Status', response.getcode()
print 'Response data', response.read()
Note that the parameters are added to the _URL_ to form URL query parameters.
You can do this simpler still by installing the [`requests`
library](http://docs.python-requests.org/en/latest/):
import requests
url = "{}resources/slmservices/templates/{}/options".format(
serverURL, templateId)
headers = {"ticket": ticket}
params = {"loginTicket": ticket}
response = requests.get(url, params=params, headers=headers)
print 'Status', response.status
print 'Response data', response.content # or response.text for Unicode
Here `requests` takes care of URL-encoding the URL query string parameters and
adding it to the URL for you, just like Java does.
|
Using scrapy to save files on a web page by extension type
Question: I am very new to Python and I am trying to use scrapy to download and save the
pdf files in this website:
<http://www.legco.gov.hk/general/chinese/counmtg/yr04-08/mtg_0708.htm#hansard>
The following is my code:
from scrapy.contrib.spiders import CrawlSpider, Rule
from scrapy.contrib.linkextractors.sgml import SgmlLinkExtractor
from scrapy.spider import BaseSpider
from scrapy.selector import HtmlXPathSelector
class legco(BaseSpider):
name = "legco"
allowed_domains = ["http://www.legco.gov.hk/"]
start_urls = ["http://www.legco.gov.hk/general/chinese/counmtg/yr04-08/mtg_0708.htm#hansard"]
rules =(
Rule(SgmlLinkExtractor(allow=r"\.pdf"), callback="save_pdf")
)
def parse_listing(self, response):
hxs = HtmlXPathSelector(response)
pdf_urls=hxs.select("a/@href").extract()
for url in pdf_urls:
yield Request(url, callback=self.save_pdf)
def save_pdf(self, response):
path = self.get_path(response.url)
with open(path, "wb") as f:
f.write(response.body)
Basically I tried to restrict the search to just links with ".pdf" and then
select by "a/@hfref".
From the output, I see this error:
> 2015-03-09 11:00:22-0700 [legco] ERROR: Spider error processing
> http://www.legco.gov.hk/general/chinese/counmtg/yr04-08/mtg_0708.htm#hansard>
Can anyone advise how can I fix my code? Thanks a lot!
Answer: First of all, _you need to use a`CrawlSpider`_ if you want the `rules` to
work. Also, the `rules` should be defined as an iterable, usually it is a
tuple (there was a missing comma).
Anyway, instead of taking this approach, I would use a normal `BaseSpider`,
loop over the links and check the `href` to end with `.pdf`, then, in the
callback, save a pdf to a file:
import urlparse
from scrapy.http import Request
from scrapy.spider import BaseSpider
class legco(BaseSpider):
name = "legco"
allowed_domains = ["www.legco.gov.hk"]
start_urls = ["http://www.legco.gov.hk/general/chinese/counmtg/yr04-08/mtg_0708.htm#hansard"]
def parse(self, response):
base_url = 'http://www.legco.gov.hk/general/chinese/counmtg/yr04-08/'
for a in response.xpath('//a[@href]/@href'):
link = a.extract()
if link.endswith('.pdf'):
link = urlparse.urljoin(base_url, link)
yield Request(link, callback=self.save_pdf)
def save_pdf(self, response):
path = response.url.split('/')[-1]
with open(path, 'wb') as f:
f.write(response.body)
(worked for me)
|
Creating a 2d colour gradient plot with 3 1D arrays
Question: So i have 3 1D arrays, x_vals, y_vals and z_vals.
I would like to plot x_vals against y_vals, with z_vals defining the colour at
the point.
from everything i have looked up it seems i need to use numpy.meshgrid,
however when i try this python just times out.
Any thoughts? Thank you!
Answer: You are looking for the `LineCollection` command. Try this
import numpy as np
import matplotlib.pyplot as plt
from matplotlib.collections import LineCollection
fig,ax = plt.subplots(1)
# some data to plot
x = np.linspace(0,1,200)
y = np.sin(10*x)
z = x**2
# creating the segments
points = np.array([x, y]).T.reshape(-1, 1, 2)
segments = np.concatenate([points[:-1], points[1:]], axis=1)
# creating LineCollection object
lc = LineCollection(segments, cmap=plt.get_cmap('jet'),norm=plt.Normalize(0, 1))
lc.set_array(z)
lc.set_linewidth(2)
# add LineCollection to plot
ax.add_collection(lc)
# set plotting range
ax.set_xlim((0,1))
ax.set_ylim((-1,1))
plt.show()
|
Implementing Matlab's weights and bias on Neurolab (Neural Network)
Question: I exported weights and bias from Matlab into python to use with neurolab. My
network has 8 inputs, 3 arrays of input weights, 4 arrays of layered weights
and 4 output neurons. This is my first time of doing this, I'll really need
help to get it done. Below is my implementation and the error I got.
import numpy as np
import neurolab as nl
net = nl.net.newff([[0, 1]], [3, 4])
input_w=[[-24.1874,24.1622,0.0755,-0.2521,4.4625,-10.7961,6.2183,0.2680],...]
input_w = np.array(input_w)
input_w = np.reshape(input_w, (8,3))
layer_w=[[-3.7940,-0.0336,-14.9024],......]
layer_w = [np.array(x) for x in (layer_w)]
layer_w = np.reshape(layer_w, (3,4))
input_bias =[0.4747,-1.2475,-1.2470]
bias_2=np.array([-10.9982,1.9692,5.0705,-0.1236])
bias_2 = np.reshape(bias_2, (4))
net.layers[0].np['w'][:] = input_w.
net.layers[1].np['w'][:] = layer_w.
net.layers[1].np['b'][:] = np.array([input_bias])
net.layers[0].np['b'][:] = bias_2
print net.sim([[0.015,0.022,0.0,0.0,0.432,0.647,0.831]])
Traceback (most recent call last):
File "C:\Python27\neural13.py", line 206, in <module>
net.layers[0].np['w'][:] = input_w
ValueError: could not broadcast input array from shape (8,3) into shape (3,1)
Thanks for your suggestions, and please feel free to ask if you need more
info.
Answer: There are several problems here.
The first problem is that you want 8 input neurons. For that, you need the
first list in newff to have a length of 8 (one min value and one max value for
each of 8 inputs). So you are ending up with only one input, not 8 (hence a
3x1 array instead of a 3x8 array). That can be fixed by changing:
net = nl.net.newff([[0, 1]], [3, 4])
to:
net = nl.net.newff([[0, 1]]*8, [3, 4])
which is a shorter way to write:
net = nl.net.newff([[0, 1], [0, 1], [0, 1], [0, 1], [0, 1], [0, 1], [0, 1], [0, 1]], [3, 4])
The next problem is that python uses a different dimension ordering (by
default) than matlab. So a 2D array with shape (8,3) would have a shape of
(3,8) in numpy. So all of your reshaping is unnecessary.
The third problem is that you have the dimensions for input_bias and bias_2
mixed up. I don't know enough about neurlab to say whether you want to change
`[3, 4]` at the beginning to `[4, 3]`, or whether you want to switch the
biases. I will assume the latter.
The final problem is that you need 8 elements in the input to net.sim, but you
only have 7.
Here is a fixed version of your code, assuming you have the biases mixed up
and with some dummy values to fill in what you left out:
import numpy as np
import neurolab as nl
net = nl.net.newff([[0, 1]]*8, [3, 4])
input_w = np.array([[-24.1874,24.1622,0.0755,-0.2521,4.4625,-10.7961,6.2183,0.2680],
[-24.1874,24.1622,0.0755,-0.2521,4.4625,-10.7961,6.2183,0.2680],
[-24.1874,24.1622,0.0755,-0.2521,4.4625,-10.7961,6.2183,0.2680]])
layer_w = np.array([[-3.7940,-0.0336,-14.9024],
[-3.7940,-0.0336,-14.9024],
[-3.7940,-0.0336,-14.9024],
[-3.7940,-0.0336,-14.9024]])
input_bias = np.array([0.4747,-1.2475,-1.2470])
bias_2 = np.array([-10.9982,1.9692,5.0705,-0.1236])
net.layers[0].np['w'][:] = input_w
net.layers[1].np['w'][:] = layer_w
net.layers[0].np['b'][:] = input_bias
net.layers[1].np['b'][:] = bias_2
print net.sim([[0.015,0.022,0.0,0.0,0.432,0.647,0.831]])
|
Try block not catching - Am I making inadvertent internet access?
Question: I accidentally disconnected my internet connection and received this error
below. However, why did this **line** trigger the error?
self.content += tuple(subreddit_posts)
Or perhaps I should ask, why did the following line **not** lead to a
`sys.exit`? It seems it should catch all errors:
try:
subreddit_posts = self.r.get_content(url, limit=10)
except:
print '*** Could not connect to Reddit.'
sys.exit()
Does this mean I am inadvertently hitting reddit's network twice?
FYI, praw is a reddit API client. And `get_content()` fetches a subreddit's
posts/submissons as a generator object.
The error message:
Traceback (most recent call last):
File "beam.py", line 49, in <module>
main()
File "beam.py", line 44, in main
scan.scanNSFW()
File "beam.py", line 37, in scanNSFW
map(self.getSub, self.nsfw)
File "beam.py", line 26, in getSub
self.content += tuple(subreddit_posts)
File "/Library/Python/2.7/site-packages/praw/__init__.py", line 504, in get_co
page_data = self.request_json(url, params=params)
File "/Library/Python/2.7/site-packages/praw/decorators.py", line 163, in wrap
return_value = function(reddit_session, *args, **kwargs)
File "/Library/Python/2.7/site-packages/praw/__init__.py", line 557, in reques
retry_on_error=retry_on_error)
File "/Library/Python/2.7/site-packages/praw/__init__.py", line 399, in _reque
_raise_response_exceptions(response)
File "/Library/Python/2.7/site-packages/praw/internal.py", line 178, in _raise
response.raise_for_status()
File "/Library/Python/2.7/site-packages/requests/models.py", line 831, in rais
raise HTTPError(http_error_msg, response=self)
requests.exceptions.HTTPError: 503 Server Error: Service Unavailable
The script (it's short):
import sys, os, pprint, praw
class Scanner(object):
''' A scanner object. '''
def __init__(self):
self.user_agent = 'debian.22990.myapp'
self.r = praw.Reddit(user_agent=self.user_agent)
self.nsfw = ('funny', 'nsfw')
self.nsfw_posters = set()
self.content = ()
def getSub(self, subreddit):
''' Accepts a subreddit. Connects to subreddit and retrieves content.
Unpacks generator object containing content into tuple. '''
url = 'http://www.reddit.com/r/{sub}/'.format(sub=subreddit)
print 'Scanning:', subreddit
try:
subreddit_posts = self.r.get_content(url, limit=10)
except:
print '*** Could not connect to Reddit.'
sys.exit()
print 'Constructing list.',
self.content += tuple(subreddit_posts)
print 'Done.'
def addNSFWPoster(self, post):
print 'Parsing author and adding to posters.'
self.nsfw_posters.add(str(post.author))
def scanNSFW(self):
''' Scans all NSFW subreddits. Makes list of posters.'''
# Get content from all nsfw subreddits
print 'Executing map function.'
map(self.getSub, self.nsfw)
# Scan content and get authors
print 'Executing list comprehension.'
[self.addNSFWPoster(post) for post in self.content]
def main():
scan = Scanner()
scan.scanNSFW()
for i in scan.nsfw_posters:
print i
print len(scan.content)
main()
Answer: It looks like `praw` is going to lazily get objects, so when you actually
_use_ `subreddit_posts` is when the request gets made, which explains why it's
blowing up on that line.
See: <https://praw.readthedocs.org/en/v2.1.20/pages/lazy-loading.html>
|
Get Data from JSON Python?
Question: I'm working on doing a live currency converter in Python. I've successfully
fetched all the data needed from the URL into Python. However I'm now trying
to call a specific string in the url. Here's my current code:
import urllib.request
import json
##Define JSON API Url
with urllib.request.urlopen("http://openexchangerates.org/api/latest.json?app_id=XXX") as url:
response = url.read()
##Print Fetched data
print (response)
As you can see I've printed all the data it's fetched, but it's now printing
specific strings from it.
My question is, how do i parse specific strings from the url ? I've heard of
json.load ,is that something i should use ?
Answer: You'll need to load the data as JSON; the [`json`
module](https://docs.python.org/3/library/json.html) can do this for you, but
you need to decode the data to text first.
import urllib.request
import json
with urllib.request.urlopen("http://openexchangerates.org/api/latest.json?app_id=XXX") as url:
response = url.read()
charset = url.info(). get_content_charset('utf-8') # UTF-8 is the JSON default
data = json.loads(response.decode(charset))
From there on out `data` is a Python object.
Judging by the
[documenation](https://openexchangerates.org/documentation#preview-api-
response) you should be able to access rates as:
print('Euro rate', data['rates']['EUR'])
for example.
|
Detect the dates from text in text file. And then list them out using python
Question: I have a text file that contains dates in the text. these dates are of format
("march 2016" or "march 2, 2016"). I wish to list them out. Can anybody help
me with this?
this is my attempt
import re
regex = '\s(\w+)\s(\d+\,)\s(\d+)' # this will match the form "str int, int" with open('./BACKGROUND OF THE SOLICITATION3.txt', 'r') as f:
text = f.read()
all_dates = [' '.join(date) for date in re.findall(regex, text)]
print all_dates
Answer:
s = " I want to detect both March 20, 2013 and February 2013 3 and list them"
import re
print(re.findall(r"([A-Z][a-z\s\d]+, \d+|[A-Z][a-z\s]+\d+)",s))
['March 20,2013', 'February 2013']
|
python NameError: name 'memberno' is not defined
Question: my code is giving me the error of
Destination[index]=inode*dof-dof
IndexError: list assignment index out of range
I have searched for this error but i cant figure out the problem in this
code.Please help me...
import numpy as np
class memberdata(object):
def__init__(self,memberno=None,backnode=None,forenode=None,materialno=None):
self.memberno=memberno
self.backnode=backnode
self.forenode=forenode
self.materialno=materialno
member=[]
member.append(memberdata('10','2','3','1'))
print "enter dof"
dof=raw_input()
dof=int(dof)
def get_destination(memberno):
inode = member[memberno-1].backnode
inode=int(inode)
jnode = member[memberno-1].forenode
jnode=int(jnode)
Destination=[]
index=0
Destination[index]=inode*dof-dof
for i in range(dof):
index=index+1
Destination[index]=Destination[index-1]+1
index=index+1
Destination[index]=jnode*dof-dof
for i in range(dof):
index=index+1
Destination[index]=Destination[index-1]+1
if __name__ == "__main__":
get_destination(memberno)
Answer:
Destination=[]
index=0
Destination[index]=inode*dof-dof
Here, you create an empty list with `[]` and then try to assign index 0, where
`Destination[0]` doesn't yet exist. The list holds 0 values, hence any index
you try to assign will be out of range.
If you simply want to add some value to the list, use
Destination.append(inode*dof-dof)
|
Python: Download CSV file, check return code?
Question: I am downloading multiple CSV files from a website using Python. I would like
to be able to check the response code on each request.
I know how to download the file using `wget`, but not how to check the
response code:
os.system('wget http://example.com/test.csv')
I've seen a lot of people suggesting using requests, but I'm not sure that's
quite right for my use case of saving CSV files.
r = request.get('http://example.com/test.csv')
r.status_code # 200
# Pipe response into a CSV file... hm, seems messy?
What's the neatest way to do this?
Answer: You can use the `stream` argument - along with `iter_content()` it's possible
to stream the response contents right into a file ([docs](http://docs.python-
requests.org/en/latest/user/advanced/#body-content-workflow)):
import requests
r = None
try:
r = requests.get('http://example.com/test.csv', stream=True)
with open('test.csv', 'w') as f:
for data in r.iter_content():
f.write(data)
finally:
if r is not None:
r.close()
|
Intellij/Pycharm can't debug Python modules
Question: I use **PyCharm** /**IntelliJ** community editions from a wile to write and
debug Python scripts, but now I'm trying to debug a **Python module** , and
PyCharm does a wrong command line instruction parsing, causing an execution
error, or maybe I'm making a bad configuration.
This is my run/debug configuration:
And this is executed when I run the module (no problems here):
/usr/bin/python3.4 -m histraw
But when I debug, this is the output in the IntelliJ console:
/usr/bin/python3.4 -m /opt/apps/pycharm/helpers/pydev/pydevd.py --multiproc --client 127.0.0.1 --port 57851 --file histraw
/usr/bin/python3.4: Error while finding spec for '/opt/apps/pycharm/helpers/pydev/pydevd.py' (<class 'ImportError'>: No module named '/opt/apps/pycharm/helpers/pydev/pydevd')
Process finished with exit code 1
As you can see, the parameters are wrong parsed, and after `-m` option a
IntelliJ debug script is passed before the module name.
I also tried just put `-m histraw` in the _Script_ field, but doesn't work,
that field is only to put Python script paths, not modules.
Any ideas?
Answer: There is another way to make it work.You can write a python script to run your
module.Then just configure PyCharm to run **this script**.
import sys
import os
import runpy
path = os.path.dirname(sys.modules[__name__].__file__)
path = os.path.join(path, '..')
sys.path.insert(0, path)
runpy.run_module('<your module name>', run_name="__main__",alter_sys=True)
Then the debugger works.
|
python picamera OSError: dlopen(libmmal.so, 6): image not found
Question: I am trying to use picamera to do a video streaming on my Mac(python 2.7). I
have installed picamera by this command:
**(venv)55-213:video_streaming mreko$ pip install picamera
Requirement already satisfied (use --upgrade to upgrade): picamera in
./venv/lib/python2.7/site-packages**
Then I wrote a py script trying to test the picamera:
**import time
import picamera
with picamera.PiCamera() as camera:
camera.resolution = (1024, 768)
camera.start_preview()
# Camera warm-up time
time.sleep(2)
camera.capture('foo.jpg')**
However,when I compile this py script,it throws an error:
**(venv)55-213:video_streaming mreko$ python test.py
Traceback (most recent call last): File "test.py", line 2, in import picamera
File "/Users/mreko/python_workstation/video_streaming/venv/lib/python2.7/site-
packages/picamera/__init__.py", line 258, in from picamera.exc import ( File
"/Users/mreko/python_workstation/video_streaming/venv/lib/python2.7/site-
packages/picamera/exc.py", line 41, in import picamera.mmal as mmal File
"/Users/mreko/python_workstation/video_streaming/venv/lib/python2.7/site-
packages/picamera/mmal.py", line 47, in _lib = ct.CDLL('libmmal.so') File
"/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/ctypes/__init__.py",
line 365, in __init__ self._handle = _dlopen(self._name, mode) OSError:
dlopen(libmmal.so, 6): image not found**
I know the extention of lib on mac is 'dylib'.I change 'libmmal.so' into
'libmmal.dylib'.However,still it can't work.
Then I search the /usr/lib/,I found there is no dylib name 'libmmal'.
So I don't know how to solve this problem.Maybe the picamera can't support
Mac? Or is there any way that I can intall libmmal.dylib file to support the
picamera?
It really makes me upset!! Thanks a lot!
Answer: The files that `picamera` is referencing are part of the
[raspberry](https://github.com/raspberrypi/firmware/tree/master/hardfp/opt/vc/lib)
[firmware](https://github.com/raspberrypi/userland) and you would need to
recompile them for your mac.
As others asked in the comments, are you sure you have connected the thin
flexband of the camera to your apple laptop? If so, how? If not, are you
running a raspberry pi and connecting to it via your mac?
|
SBCL Run Shell Command
Question: I've seen [Executing a shell command from Common
Lisp](http://stackoverflow.com/q/6065446/1281433) and its answers, but I'm
still not sure whether SBCL provides a way execute shell commands from code.
The [SBCL Manual](http://www.sbcl.org/manual/#sb_002dposix) does support
POSIX, but I was hoping for something a bit more higher level. Specifically, I
want to call a Python script and capture the return value. Is there any way to
do this?
Answer: Given the file `test.py`:
import sys
sys.exit(42)
You can run it with `sb-ext:run-program` and examine the exit code as follows:
CL-USER> (sb-ext:run-program "python" '("test.py") :search t :wait t)
#<SB-IMPL::PROCESS :EXITED 42>
CL-USER> (sb-ext:process-exit-code *)
42
|
Maya, Python, How do i get the name of an object based on vertex selection?
Question: I got the code working like this until i realized that the vertex index
changes for geometry with over 100 vertices...
I assumed i could just split the string and everything would be dandy
import maya.cmds as mc
selPoints = mc.ls(sl = True) # list of names of selected vertices
objName = (str(selPoints[0]))[:-9]
print selPoints
print objName
Heres what it returned:
[u'pCylinder25.vtx[4]', u'pCylinder25.vtx[24]']
pCylinder
I'm trying to hack off the portion with '.vtx[integer]'
I may be going about this completely wrong, and there may be a dead simple way
to do this.
Thanks
Answer: Wouldn't it be awesome if it were easy to get the object from Maya? From
experience, I know it can be frustrating since MEL/maya.cmds doesn't use an
object-oriented approach.
Anyhow, you should refer to the
[documentation](https://docs.python.org/3.1/library/stdtypes.html#string-
methods) often for more info on the variety of `string` methods you can use.
Really comes in handy _all the time_!
To answer your question, you can use `.split` or `.find`, whichever you
prefer.
print selPoints[0].split('.vtx')[0]
print selPoints[0][0:selPoints[0].find('.vtx')]
The `split` method returns a list of strings created by the delimiter string
`'.vtx'`. Then, taking the first element from that list will always be the
object name.
The `find` method returns the index of the substring `'.vtx'`, so the second
example simply uses slicing syntax to return the correct string.
|
Compiling Python script to exe
Question: I recently created a script using Python 2.7 and pygame. I have tried using
`py2exe`, but when I run the file it created, it gives me this error:
G:\Downloads2\GAME\dist\ANNECUTE.exe\zipextimporter.py:82: RuntimeWarning: import display: No module named _view
(ImportError: No module named _view)
G:\Downloads2\GAME\dist\ANNECUTE.exe\zipextimporter.py:82: RuntimeWarning: import draw: No module named _view
(ImportError: No module named _view)
G:\Downloads2\GAME\dist\ANNECUTE.exe\zipextimporter.py:82: RuntimeWarning: import image: No module named _view
(ImportError: No module named _view)
G:\Downloads2\GAME\dist\ANNECUTE.exe\zipextimporter.py:82: RuntimeWarning: import pixelcopy: No module named _view
(ImportError: No module named _view)
G:\Downloads2\GAME\dist\ANNECUTE.exe\zipextimporter.py:82: RuntimeWarning: import transform: No module named _view
(ImportError: No module named _view)
Traceback (most recent call last):
File "ANNECUTE.py", line 45, in <module>
File "pygame\__init__.pyc", line 70, in __getattr__
NotImplementedError: display module not available
(ImportError: No module named _view)
I used this in the `setup.py` file:
from distutils.core import setup
import py2exe, sys, os
sys.argv.append('py2exe')
setup(
options = {'py2exe': {'bundle_files': 1}},
windows = [{'script': "ANNECUTE.py"}],
zipfile = None,
)
Answer: Try adding
import pygame._view
To `zipextimporter.py`. This will import _view and should eliminate your
problem.
|
How to normalise unique dates for graphing
Question: I've currently got a data-set from an application, but the problem is the data
is listed whenever it changes, not on a regular interval. For example I could
have 20 entries in one day and then nothing for two days, then one, then one
next month.
I want to graph the data I have, but with a consistent time scale - currently
it just graphs every entry with every date one after the other.
I have thought about the problem and an idea that came to mind would be
determining the start and end date of the data, dividing it by the graphing
resolution desired, (eg 100 entries), then for each entry working out the
closest result in the data-set BEFORE the resolution sample. ie one of the
samples for graphing is 10th of january, it finds the first sample before the
10th of january and uses it. Then with 100 samples you can graph with a
consistent time scale.
Any ideas on how to actually achieve this would be wonderful! I'm looking to
normalize in python and then render in a browser with google chart api.
Here is an example of the data:
10/03/2015 10:55 7385498415
10/03/2015 9:15 7379639094
10/03/2015 8:55 7376777516
10/03/2015 8:35 7368304217
10/03/2015 8:12 7358015859
8/03/2015 9:22 7358015859
8/03/2015 4:27 7354221274
8/03/2015 4:07 7346810719
7/03/2015 4:25 7339695326
7/03/2015 4:25 7339698276
6/03/2015 13:08 7339701226
6/03/2015 13:04 7317905872
6/03/2015 12:44 7309771372
6/03/2015 12:24 7300851599
6/03/2015 12:04 7292557469
6/03/2015 11:39 7283439433
6/03/2015 11:00 7278056128
6/03/2015 10:41 7267320628
6/03/2015 10:35 7265158228
6/03/2015 10:21 7265158228
6/03/2015 10:01 7255260402
6/03/2015 7:06 7246047762
5/03/2015 15:39 7245760885
5/03/2015 13:41 7170760885
4/03/2015 21:21 5595760885
4/03/2015 18:59 5590496476
4/03/2015 18:59 5585251201
Answer: There’s no need to “normalise” the data, as the Google Charts API has support
for dates directly. Not only is adjusting the data more difficult, but it will
also give a skewed impression.
We can start with the [Dates and
Times](https://developers.google.com/chart/interactive/docs/datesandtimes)
section of their documentation:
> To create a new `Date` object, you call the `Date()` constructor with the
> new keyword, with arguments to specify components of the date. These
> arguments take the form of several numbers corresponding to the different
> properties of your date.
>
>
> new Date(Year, Month, Day, Hours, Minutes, Seconds, Milliseconds)
>
A row in a Google Chart is an `[x, y]` list. The first entry will be one of
these Date() constructors, and the second will be the value. So we need to
take the data you’ve provided, parse the dates and turn them into Date()
constructors. (Note that we can omit the second and millisecond arguments.)
Here’s a simple script that does this, and then wraps each time in a row that
we can supply to a Google Chart:
from datetime import datetime
# This string is a copy of the example data set. The newlines have been
# replaced with '\n' escape codes to save vertical space on Stack Overflow.
DATASET = """10/03/2015 10:55 7385498415\n10/03/2015 9:15 7379639094\n10/03/2015 8:55 7376777516\n10/03/2015 8:35 7368304217\n10/03/2015 8:12 7358015859\n8/03/2015 9:22 7358015859\n8/03/2015 4:27 7354221274\n8/03/2015 4:07 7346810719\n7/03/2015 4:25 7339695326\n7/03/2015 4:25 7339698276\n6/03/2015 13:08 7339701226\n6/03/2015 13:04 7317905872\n6/03/2015 12:44 7309771372\n6/03/2015 12:24 7300851599\n6/03/2015 12:04 7292557469\n6/03/2015 11:39 7283439433\n6/03/2015 11:00 7278056128\n6/03/2015 10:41 7267320628\n6/03/2015 10:35 7265158228\n6/03/2015 10:21 7265158228\n6/03/2015 10:01 7255260402\n6/03/2015 7:06 7246047762\n5/03/2015 15:39 7245760885\n5/03/2015 13:41 7170760885\n4/03/2015 21:21 5595760885\n4/03/2015 18:59 5590496476\n4/03/2015 18:59 5585251201"""
# For each line in the dataset, print the row which will be added to the
# Google Chart.
for line in DATASET.splitlines():
date, value = line.split(" ")
# First we parse the date string using strptime(), and write it back out
# as a Date() constructor to use in JavaScript
date_obj = datetime.strptime(date, "%d/%m/%Y %H:%M")
js_date = date_obj.strftime("new Date(%Y, %m, %d, %H, %M, %s, %f)")
js_value = value.strip()
print "[%s, %s]," % (js_date, js_value)
Here’s a few rows of the output:
[new Date(2015, 03, 10, 10, 55, 1425984900, 000000), 7385498415],
[new Date(2015, 03, 10, 09, 15, 1425978900, 000000), 7379639094],
[new Date(2015, 03, 10, 08, 55, 1425977700, 000000), 7376777516],
[new Date(2015, 03, 10, 08, 35, 1425976500, 000000), 7368304217],
Then I took the [scatter plot
example](https://developers.google.com/chart/interactive/docs/gallery/scatterchart)
from Google’s Chart gallery, dropped in the date values I got from the script
above, and changed a few of the options. This is what it looks like:
and here’s the HTML:
<head>
<!--Load the AJAX API-->
<script type="text/javascript" src="https://www.google.com/jsapi"></script>
<script>
google.load("visualization", "1", {packages:["corechart"]});
google.setOnLoadCallback(drawChart);
function drawChart() {
var data = google.visualization.arrayToDataTable([
['Date', 'Value'],
[new Date(2015, 03, 10, 10, 55), 7385498415],
[new Date(2015, 03, 10, 09, 15), 7379639094],
[new Date(2015, 03, 10, 08, 55), 7376777516],
[new Date(2015, 03, 10, 08, 35), 7368304217],
[new Date(2015, 03, 10, 08, 12), 7358015859],
[new Date(2015, 03, 08, 09, 22), 7358015859],
[new Date(2015, 03, 08, 04, 27), 7354221274],
[new Date(2015, 03, 08, 04, 07), 7346810719],
[new Date(2015, 03, 07, 04, 25), 7339695326],
[new Date(2015, 03, 07, 04, 25), 7339698276],
[new Date(2015, 03, 06, 13, 08), 7339701226],
[new Date(2015, 03, 06, 13, 04), 7317905872],
[new Date(2015, 03, 06, 12, 44), 7309771372],
[new Date(2015, 03, 06, 12, 24), 7300851599],
[new Date(2015, 03, 06, 12, 04), 7292557469],
[new Date(2015, 03, 06, 11, 39), 7283439433],
[new Date(2015, 03, 06, 11, 00), 7278056128],
[new Date(2015, 03, 06, 10, 41), 7267320628],
[new Date(2015, 03, 06, 10, 35), 7265158228],
[new Date(2015, 03, 06, 10, 21), 7265158228],
[new Date(2015, 03, 06, 10, 01), 7255260402],
[new Date(2015, 03, 06, 07, 06), 7246047762],
[new Date(2015, 03, 05, 15, 39), 7245760885],
[new Date(2015, 03, 05, 13, 41), 7170760885],
[new Date(2015, 03, 04, 21, 21), 5595760885],
[new Date(2015, 03, 04, 18, 59), 5590496476],
[new Date(2015, 03, 04, 18, 59), 5585251201]
]);
var options = {
hAxis: {title: 'Date'},
vAxis: {title: 'Variable'},
legend: 'none',
height: 500,
width: 1100
};
var chart = new google.visualization.ScatterChart(document.getElementById('chart_div'));
chart.draw(data, options);
}
</script>
</head>
<body>
<div id="chart_div"></div>
</body>
|
python with app engine error import ndb
Question: I have a problem with app engine, I use it with django. I read a lot of thinks
about the problem, but I never find a solution. I use Pycharm for the
development, I just use app engine in the models.py
For import ndb I make this :
from google.appengine.ext import ndb
There is my problem: If I use "dev_appserver.py ." I don't have any problems
and the application work fine.
But when I use "python manage.py test mobile_backend/" I have an error.
> from google.appengine.ext import ndb
> ImportError: No module named appengine.ext
After some hours searching, the solution I have verified few things:
-I put "'google.appengine.ext.ndb.django_middleware.NdbDjangoMiddleware',
" in the top of my MIDDLEWARE_CLASSES settings
-I have the google-cloud-sdk.
-I have in my .profile "export PATH=$PATH:/home/david/google-cloud-sdk/platform"
-I attempt to change the PYTHONPATH to integrated the PATH of google-cloud-sdk, but without success.
Pycharm show me a problemwith the import, he know google, but don't know the
end of the import.(appengine.ext)
I have search and I have the ndb module with this path :
/home/david/google-cloud-sdk/platform/google_appengine/google/appengine/ext/ndb
Somebody can help me?
Answer: The problem is you are trying to use App Engine infrastructure but have not
properly set up the App Engine environment. This is documented in the App
Engine Local Unit Testing page in the [Setting up a testing
framework](https://cloud.google.com/appengine/docs/python/tools/localunittesting#Python_Setting_up_a_testing_framework)
section:
sdk_path = '/home/david/google-cloud-sdk/platform/google_appengine'
sys.path.insert(0, sdk_path)
import dev_appserver
dev_appserver.fix_sys_path()
|
Unable to process python subprocess stderr on windows
Question: I am trying to simple file copy operation using `dd` under Windows. The code
is simple. Just open the command using subprocess and read `stderr`. Then
process the `stderr` to show the progress of the operation. Here is the
sample/simple code which I an trying to accomplish:-
import time
import signal
import subprocess
import os
def dd_win():
windd = "dd.exe"
in_file = os.path.join("E:", "test-in.iso")
out_file = os.path.join("E:", "test-out.iso")
parameter1 = "if=" + in_file
parameter2 = "of=" + out_file
parameter3 = "bs=1M"
parameter4 = "--progress"
command = [windd, parameter1, parameter2, parameter4]
print command
dd_process = subprocess.Popen(command, stderr=subprocess.PIPE, stdout=subprocess.PIPE, shell=True, bufsize=0)
while dd_process.poll() is None:
time.sleep(.1)
line = dd_process.stderr.readline()
if not line:
break
print ">>>>>", line.strip()
if dd_process.poll() is not None:
print "Process finished."
dd_win()
Here is wht I got as an output. I could see the `stderr` but unable to process
the transfer bytes to convert in to mega bytes:-
C:\Users\user\Documents>python test.py
['dd.exe', 'if=E:test-in.iso', 'of=E:test-out.iso', '--progress']
>>>>> rawwrite dd for windows version 0.6beta3.
>>>>> Written by John Newbigin <[email protected]>
>>>>> This program is covered by terms of the GPL Version 2.
>>>>>
175,882,240 # <--- Problem output line. Unable to assign to other variable for progress calculation
Process finished.
I actually do not know where the numbers are coming from. Is it from `stderr`
or buffer? If it is from `stderr` then ">>>>>" should have be printed before
the numbers. I work on Windows 7 and using windows version of dd.
Any help is appreciated.
Answer: As discussed in chat, the numbers are coming from stderr. By printing the
ascii-indexes of each character in line, we discovered that the final line
returned by readline() is `\t75,881,728 \r175,882,240 \r\n`. It looks like the
`\r` embedded in the middle of this string (which DD outputs) is confusing
your code.
|
python - igraph plot not available (cairo already installed)
Question: I've installed py2cairo using brew, but keep getting errors when trying to
plot with igraph. I get the following error:
>>> import igraph as ig
>>> from igraph import *
>>> UG = ig.Graph()
>>> UG.add_vertex('a')
>>> UG.add_vertex('b')
>>> UG.add_vertex('c')
>>> UG.add_vertex('d')
>>> UG.add_edge('a','d')
>>> UG.add_edge('a','c')
>>> UG.add_edge('b','c')
>>> UG.add_edge('b','a')
>>> layout = UG.layout_kamada_kawai()
>>> plot(UG,layout = layout)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File ".../anaconda/lib/python2.7/site-packages/igraph/drawing/__init__.py", line 427, in plot
result = Plot(target, bbox, background="white")
File ".../anaconda/lib/python2.7/site-packages/igraph/drawing/__init__.py", line 122, in __init__
self._surface_was_created = not isinstance(target, cairo.Surface)
File ".../anaconda/lib/python2.7/site-packages/igraph/drawing/utils.py", line 396, in __getattr__
raise TypeError("plotting not available")
TypeError: plotting not available
Answer: `brew` probably installs `py2cairo` for its own Python, while you are running
igraph under Anaconda Python. A module installed for one Python distribution
on your machine will not appear magically under the other Python distribution,
so you'll either have to get `py2cairo` for Anaconda Python or compile the
Python interface of igraph for Homebrew's Python.
|
Unit Testing JWT token exipiration: Django REST
Question: How do I test the case of attempting to refresh an expired token? Or the case
of trying to exceed `JWT_REFRESH_EXPIRATION_DELTA`?
I'm looking for the most pythonic/djangotacular way to unit test a token
refresh endpoint. AFAICT, my endpoint is working fine-it's refreshing the
token, and when I test it via python REPL, it does what I expect. But since
this is a documented bug I'm fixing, I'd like to end up with the fix under my
test harness. Testing the positive case is easy, but I'm unsure of how to
proceed from here. I don't want to do some delay loop or something like that,
since that would undermine the whole unit test ideology of running quickly and
in isolation...
my tests are currently using the `response = self.client.post(...)` style.
Answer: I can think of two ways to do what you want, and both involve using
[mocks](https://docs.python.org/3/library/unittest.mock.html). You must learn
to use mocks if you want to do serious isolated unit testing. ;)
First, mock the [`validate`](https://github.com/GetBlimp/django-rest-
framework-jwt/blob/master/rest_framework_jwt/serializers.py#L141) method of
the `RefreshJSONWebTokenSerializer` to raise `serializers.ValidationError`:
from rest_framework import serializers
@mock.patch('rest_framework_jwt.RefreshJSONWebTokenSerializer.validate')
def test_token_expiry_refresh(self, validate_mock):
validate_mock.side_effect = serializers.ValidationError('Refresh has expired.')
response = self.client.post('/refresh-token-url/')
self.assertEquals(response.status, 400) # I believe it's this code what ValidationError should return
A second option is a bit more involved and would imply playing with the
current datetime:
import datetime
# http://stackoverflow.com/a/5437199/356729
class FakeDateTime(datetime):
"A manipulable datetime replacement"
def __new__(cls, *args, **kwargs):
return datetime.__new__(datetime, *args, **kwargs)
@patch('rest_framework_jwt.RefreshJSONWebTokenSerializer.datetime', FakeDateTime)
def test_token_expiry_refresh(self):
FakeDateTime.utcnow = classmethod(lambda cls: datetime.utcnow() + timedelta(0, 10))
response = self.client.post('/refresh-token-url/')
self.assertEquals(response.status, 400)
I prefer the first option since it's easier.
|
Open SSH connection on exit Python
Question: I am writing a little script which picks the best machine out of a few dozen
to connect to. It gets a users name and password, and then picks the best
machine and gets a hostname. Right now all the script does is print the
hostname. What I want is for the script to find a good machine, and open an
ssh connection to it with the users provided credentials.
So my question is how do I get the script to open the connection when it
exits, so that when the user runs the script, it ends with an open ssh
connection.
I am using sshpass.
Answer: You can use the os.exec* function to replace the Python process with the
callee:
import os
os.execl("/usr/bin/ssh", "user@host", ...)
<https://docs.python.org/2/library/os.html#os.execl>
|
Python continue for loop after exception
Question: I'm trying to create a new version of a file that excludes NULL bytes. I'm
using the code below to attempt this however it's still breaking on the NULL
byte. How should I structure the `for` statement and `try-catch` block to keep
going after the exception?
import csv
input_file = "/data/train.txt"
outFileName = "/data/train_no_null.txt"
############################
i_f = open( input_file, 'r' )
reader = csv.reader( i_f , delimiter = '|' )
outFile = open(outFileName, 'wb')
mywriter = csv.writer(outFile, delimiter = '|')
i_f.seek( 0 )
i = 1
for line in reader:
try:
i += 1
mywriter.writerow(line)
except csv.Error:
print('csv choked on line %s' % (i + 1))
pass
EDIT:
Here's the error message:
Traceback (most recent call last):
File "20150310_rewrite_csv_wo_NULL.py", line 26, in <module>
for line in reader:
_csv.Error: line contains NULL byte
UPDATE:
I'm using this code:
i_f = open( input_file, 'r' )
reader = csv.reader( i_f , delimiter = '|' )
# reader.next()
outFile = open(outFileName, 'wb')
mywriter = csv.writer(outFile, delimiter = '|')
i_f.seek( 0 )
i = 1
for idx, line in enumerate(reader):
try:
mywriter.writerow(line)
except:
print('csv choked on line %s' % idx)
and now get this error:
Traceback (most recent call last):
File "20150310_rewrite_csv_wo_NULL.py", line 26, in <module>
for idx, line in enumerate(reader):
_csv.Error: line contains NULL byte
Answer: You can catch all errors with the following code...
for idx, line in enumerate(reader):
try:
mywriter.writerow(line)
except:
print('csv choked on line %s' % idx)
|
how to make a function work in python
Question: I wrote the following code in python and it works fine until I try to make it
a function, can anyone help?
import random
def club():
members=int(input("members"))
print (random.randint(1, members))
Answer: You have to use 4 spaces ( or tab) per indentation level. And call the
function of course.
import random
def club():
members=int(input("members"))
print (random.randint(1, members))
club()
|
Keeping Score in python code
Question: What do I have to do in order to have a score board for my code because I need
a score board. I tried a while statement but got lost there. Can you help me?
So lost.
import random
def main_menu():
option = input("Play the game (P) , View the game credits (V), or Quit (Q)")
if (option == "Play the game") or (option == "P"):
riddles = [
{"riddle": "What walks on four legs in the morning, two legs in the afternoon, and three in the evening?",
"answer": ["Monkey", "Humans", "Nothing Silly"],
"correct": "2"},
{"riddle": "What has roots as nobady sees?",
"answer": ["River", "Famliy Tree", "Mountain"],
"correct": "3"},
{"riddle": " I am the ruin of men, and yet they lust for me. \
I have no power, no strength, and yet I am the might of kings and armies. \
I am hard as dragons scales, yet I flow like water. \
Men dream of me, and yet once found I am cast aside. \
I am a dancing rainbow, ever chased, never caught.",
"answer": ["Gold", "Sex", "Mountain"],
"correct": "1"}]
print("Welcome to the Hell of Riddles!!!!")
print("Hope you can think")
random.shuffle(riddles)
for riddle in riddles:
print (riddle["riddle"])
for i, choice in enumerate(riddle["answer"]):
print(str(i + 1) + ". " + choice)
answer = input("Choose the number of the answer:")
if answer == riddle["correct"]:
print("Congratz! You can think!!!")
else:
print("Not correct... Pathetic and disappointing.")
elif (option == "View the game credits") or (option == "V"):
print("This game is brought to you by: Hailey Reisner and Ashleigh Woodard")
elif (option == "Quit") or (option == "Q"):
print("QUITER")
print(main_menu())
Answer: create a counter and add to it for correct answers. You can also create a
counter for wrong answer
Of course you want to declare these variables first.
so the code to increment your counter would be like : rightAnswer += 1
if answer == riddle["correct"]:
print("Congratz! You can think!!!")
rightAnswer+=1
else:
print("Not correct... Pathetic and disappointing.")
wrongAnswer+=1
print('Right: %d\tWrong: %d) % (rightAnswer, wrongAnswer)
|
asking for alternate method apart from eval in python
Question: **Problem i am solving:** i am giving liberty to user to make conditions and
actions for making rules while inserting data into a database and evaluate
these conditions and action, i could not think anything else from using eval ,
an example of datastructure i created for such purpose is
action_var = ""
a_hash = {"condition":a_condition,
"action":a_hash}
a_condition ={"param":"abc",
"operator":">",
"value":"cde"}
a_action = {"param":action_var,
"operation":"=",
"value":"action
So my plan is to take condition id from user and action id from user and then
use eval to evaluate the expression .
**Help** : Am i going in right direction, is there alternate method to do this
?
**P.S:** I can't use triggers on database, I am kind of using orm wrapper for
lmdb. So i use write command at base level.
Edit: i want to have multiple conditions, with and/or mixed, with brackets.
Thanks
Answer: You don't need to use `eval`. Map those operators to functions and then apply
the functions to the arguments. Consider:
>>> import operator
>>> operators = {}
>>> operators['>'] = operator.gt
>>> operators['>'](*[1, 2])
False
>>> 1 > 2
False
|
Websocket connection closed with an error "Received unexpected continuation frame."
Question: I were just trying to use WebSockets. i wrote server code in python. The
server is running fine but when tried to connect to the socket using browser,
I'm getting the error
> "WebSocket connection to 'ws://localhost:9876/' failed: Received unexpected
> continuation frame"
When referring on internet, I understood it is something related to framing of
data that sent from the server. I've tried to follow
[these](http://tools.ietf.org/html/rfc6455#section-5.6) (rfc6455) standards
when sending a data, even I can't achieve a websocket connection. Almost
similar question is asked
[here](http://stackoverflow.com/questions/10490820/websockets-unresolvable-
received-unexpected-continuation-frame-error), but it is an old post also the
solution is not clear.
This is my pretty simple server code..
import socket
def handle(s):
print repr(s.recv(4096))
s = socket.socket()
s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR,1)
s.bind(('',9876))
s.listen(2)
handshakes='\
HTTP/1.1 101 Web Socket Protocol Handshake\r\n\
Upgrade: WebSocket\r\n\
Connection: Upgrade\r\n\
Sec-WebSocket-Origin: null\r\n\
Sec-WebSocket-Location: ws://localhost:9876/\r\n\
'
def handshake(hs):
hslist = hs.split('\r\n')
body = hs.split('\r\n\r\n')[1]
key = ''
cc = '258EAFA5-E914-47DA-95CA-C5AB0DC85B11'
for h in hslist:
if h.startswith('Sec-WebSocket-Key:'):
key = h[19:]
else:
continue
import hashlib
import base64
s = hashlib.sha1()
s.update(key+cc)()
h = s.digest()
return base64.b64encode(h)
def sender(data, conn):
first_byte = chr(0x00)
payload = data.encode('utf-8')
pl = first_byte + payload + chr(0xFF)
conn.send(pl)
while True:
c,a = s.accept()
msg = c.recv(4096)
if(msg):
print msg
print 'sending handshake ...'
handshakes += 'Sec-WebSocket-Accept: '+str(handshake(msg))+'\r\n\r\n'
print handshakes
c.send(handshakes)
sender("Hello", c)
break;
And the html, index.html
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>Web Socket Example</title>
<meta charset="UTF-8">
<script>
window.onload = function() {
var s = new WebSocket("ws://localhost:9876/");
s.onopen = function(e) { alert("opened"); }
s.onclose = function(e) { alert("closed"); }
s.onmessage = function(e) { alert("got: " + e.data); }
};
</script>
</head>
<body>
<div id="holder" style="width:600px; height:300px"></div>
</body>
</html>
I'm running this code like this..
./server.py & python -m SimpleHTTPServer 8888
after running the server, when I hit localhost:8888 using browser, it alerts
"opened" (means handshaking is done) at the same time alerts "closed"
(connection closed) with the above error on console.
Not very clear how to debug this issue.
I'm using browser Chrome (version: 41), Python 2.7, Websocket 13.
Answer: It works when I changed the sender function like this..
...
def sender(data, conn):
length = len(data)
if length <= 125:
ret = bytearray([129, length])
for byte in text.encode("utf-8"):
ret.append(byte)
conn.send(ret)
...
|
Django Sending Email : SMTPServerDisconnected: Connection unexpectedly closed
Question: hello i want to sending email activation use django registration redux.
this is my setting.py
EMAIL_BACKEND = 'django.core.mail.backends.smtp.EmailBackend'
ACCOUNT_ACTIVATION_DAYS = 3
EMAIL_HOST = 'smtp.gmail.com'
EMAIL_HOST_USER = '[email protected]'
EMAIL_HOST_PASSWORD = 'blahpassword'
EMAIL_PORT = 465
EMAIL_USE_SSL = True
LOGIN_REDIRECT_URL = '/'
when i try with
> python manage.py shell
>
> from django.core.mail import send_mail
>
> send_mail('Test', 'This is a test', '[email protected]',
> ['[email protected]'])
i am getting error like this:
Traceback (most recent call last):
File "<console>", line 1, in <module>
File "/home/apsijogja/djangogirls/myvenv/local/lib/python2.7/site-packages/django/core/mail/__init__.py", line 62, in send_mail
return mail.send()
File "/home/apsijogja/djangogirls/myvenv/local/lib/python2.7/site-packages/django/core/mail/message.py", line 286, in send
return self.get_connection(fail_silently).send_messages([self])
File "/home/apsijogja/djangogirls/myvenv/local/lib/python2.7/site-packages/django/core/mail/backends/smtp.py", line 92, in send_messages
new_conn_created = self.open()
File "/home/apsijogja/djangogirls/myvenv/local/lib/python2.7/site-packages/django/core/mail/backends/smtp.py", line 50, in open
self.connection = connection_class(self.host, self.port, **connection_params)
File "/usr/lib/python2.7/smtplib.py", line 249, in __init__
(code, msg) = self.connect(host, port)
File "/usr/lib/python2.7/smtplib.py", line 310, in connect
(code, msg) = self.getreply()
File "/usr/lib/python2.7/smtplib.py", line 361, in getreply
raise SMTPServerDisconnected("Connection unexpectedly closed")
SMTPServerDisconnected: Connection unexpectedly closed
can you help me solve this problem?
Answer: Please look into this Link: <https://code.djangoproject.com/ticket/9575> and
try sending via shell, it should work
|
How to calculate number of downtimes and Total downtime and average downtime in the below xml file using python
Question: How to calculate downtime and average downtime and total down time?
Answer: The overallAvailability is an attribute of the tag ServiceAvailabiltyReport,
so your code needs to look like this.
import glob
import xml.etree.ElementTree as ET
sum = 0; count = 0; avgTime = 0
for fName in glob.glob("*.xml"):
tree = ET.parse(fName)
root = tree.getroot()
for tag in root.iter('ServiceAvailabilityReport'):
sum += float(tag.attrib["overallAvailability"])
count += 1
avgTime = sum / count
print avgTime
Also, just a a side note, the xml file you posted had some issues including
missing closing tags etc. I'm not sure if this is true for all your files, or
if it is an artefact of the copy paste.
|
Django: communicate with TCP server (with twisted?)
Question: I have a django application, that needs to talk to a remote TCP server. This
server will send packages and depending on what the package is, I need add
entries to the database and inform other parts of the application. I also need
to actively send requests to the TCP server, for instance when the user
navigates to a certain page, I want to subscribe to a certain stream on the
TCP server. So communication in both directions need to work.
So far, I use the following solution:
I wrote a custom Django command, that I can start with
python manage.py listen
This command will start a twisted socket server with `reactor.connectTCP(IP,
PORT, factory)` and since it is a django command, I will have access to the
database and all the other parts of my application.
But since I also want to be able to send something to the TCP server,
triggered by a certain django view, I have an additional socket server, that
starts within my twisted application by `reactor.listenTCP(PORT,
server_factory)`.
To this server, I will then connect directly in my django application, within
a new thread:
class MSocket:
def __init__(self):
self.stopped = False
self.socket = None
self.queue = []
self.process = start_new_thread(self.__connect__, ())
atexit.register(self.terminate)
def terminate(self):
self.stopped = True
try:
self.socket.close()
except:
pass
def __connect__(self):
if self.stopped:
return
attempts = 0
self.socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
while True and not self.stopped:
try:
print "Connecting to Socket Server..."
self.socket.connect(("127.0.0.1", settings.SOCKET_PORT))
print "Connection Successful!"
for msg in self.queue:
self.socket.send(msg)
self.queue = []
break
except:
pause = min(int(round(1.2**attempts)), 30)
print "Connection Failed! Try again in " + str(pause) + " seconds."
sleep(pause)
attempts += 1
self.__loop__()
def __loop__(self):
if self.stopped:
return
while True and not self.stopped:
try:
data = self.socket.recv(1024)
except:
try:
self.socket.close()
except:
pass
break
if not data:
break
self.__connect__()
def send(self, msg):
try:
self.socket.send(msg)
return True
except:
self.queue.append(msg)
return False
m_socket = MSocket()
`m_socket` will then be imported by the main `urls.py` so that it starts with
django.
So my setup looks kind this:
Sending to TCP Server:
Django (connect:8001) -------> (listen:8001) Twisted (connect:4444) ------> (listen:4444) TCP-Server
Receiving from TCP Server
TCP-Server (listen:4444) ------> (connect:4444) Twisted ---(direct access)---> Django
It all seems to work that way, but I fear that this is not a really good
solution, since I have to open this extra TCP connection. So my question would
be now, if the setup can be optimized (and I'm sure it can) and how it can be
done.
Answer: This is not going to work unless you monkey patch Django (as mentioned by
@pss) I had a similar situation so this is what I did.
1. Run a separate twisted deamon.
2. To communicate from Django to Twisted, use Unix sockets. The local twisted server can listen on Unix sockets (AF_UNIX) and Django can simply connect to that socket. This will avoid going through the TCP stack
3. To communicate from Twisted to Django, you have multiple options, a) call Django url with the data b) launch a script (Django management command) c) Use celery to launch the the above Django command d) Use a queue (zeromq or rabbit) and have your Django management command listen in on the queue (preferred)
With the last option, you get much better throughput, durability and it scales
well.
|
Color a pixel in python opencv
Question: I need to color a pixel in an image. I use opencv and python.
I tried `img[x,y]=[255 255 255]` to color a `pixel(x,y)` but it wont work :(
Is there is any mistake in this?
Can you suggest any method?
Thanks in advance.
Answer: This works for me, just change it to load your own image:
import cv2
img = cv2.imread("C:\calibrate\chess\color001.jpg", cv2.CV_LOAD_IMAGE_COLOR);
## Make pixels row and column 300-400 black
img[300:400,300:400] = (0,0,0)
cv2.imshow('title',img)
cv2.waitKey(0)
cv2.destroyAllWindows()
|
Verifying IP address using regex in Python
Question: I am trying to validate an IP address. Following is the code. Can anyone
please tell me what is wrong in the code?
import re
ip = '355.4'
m = re.match('^((?:1?\d{0,2}|2[0-4]\d{1}|25[0-5]).){3}(?:1?\d{0,2}|2[0-4]\d{1}|25[0-5])$', ip)
if m:
print "correct"
print m.groups()
else:
print "wrong"
According to the IP given, it should print `wrong` as output but it prints
`correct ('4',)` as the output.
Answer: If you are allowed to `not to use regex`, you can use python's socket package
. `inet_aton("string")` converts the `string` to `ip` address,if this is not
valid ip then it will throw exception.
Simple example I have tried:
import socket
def check_valid(address):
try:
socket.inet_aton(address)
return address.count('.') == 3
except socket.error:
return False
if __name__ == "__main__":
print check_valid("192.168.1.255")
It will check all valid ip address like `192.168.1.257` is invalid while
`192.168.1.255` is valid.
|
Pipe result from subprocess to unix sort
Question: I am calling a perl script on an external txt files from python, and printing
the output to an outfile. But instead I want to pipe the output to unix's
sort. Right now I am not piping, but are writing the output from the perl
program first, then doing by combining my code under, and [this stackoverflow
answer](http://stackoverflow.com/a/14409939/2169327).
import subprocess
import sys
import os
for file in os.listdir("."):
with open(file + ".out", 'w') as outfile:
p = subprocess.Popen(["perl", "pydyn.pl", file], stdout=outfile)
p.wait()
Answer: To emulate the shell pipeline:
#!/usr/bin/env python
import pipes
import subprocess
pipeline = "perl pydyn.pl {f} | sort >{f}.out".format(f=pipes.quote(filename))
subprocess.check_call(pipeline, shell=True)
without invoking the shell in Python:
#!/usr/bin/env python
from subprocess import Popen, PIPE
perl = Popen(['perl', 'pydyn.pl', filename], stdout=PIPE)
with perl.stdout, open(filename+'.out', 'wb', 0) as outfile:
sort = Popen(['sort'], stdin=perl.stdout, stdout=outfile)
perl.wait() # wait for perl to finish
rc = sort.wait() # wait for `sort`, get exit status
|
Complicated sorting in Python
Question: I need to sort a list of strings.
However, I do not want to sort it using the first character, so I cannot use
`.sort()`
I have a list:
records = ["Bibble - 1300 / 2000",
"Jim Foo - 900 / 2000",
"Bibble - 1600 / 2000",
"Bibble - 1000 / 2000"]
I want to sort by their score out of 2000. I want an output that looks
something like this:
>>> Jim Foo - 900 / 2000
Bibble - 1000 / 2000
Bibble - 1300 / 2000
Bibble - 1600 / 2000
In the example above, I sorted it by smallest to largest. I also want to know
how I would sort this list biggest score to smallest score.
I've tried `.sort()`, but It's nothing like what I want. `.sort()` sorts it
with the first character which I do not want:
>>> records.sort()
>>> records
['Bibble - 1000 / 2000', 'Bibble - 1300 / 2000', 'Bibble - 1600 / 2000', 'Jim Foo - 900 / 2000']
>>>
Is there anyway of doing this, possibly in regular expression?
Is it also possible, so if i were to add more scores into the list I would
still be able to sort it this way?
Answer: You can use `sorted` function with a proper `key` and use `re.split` :
>>> import re
>>> sorted(records,key=lambda x:int(re.split(r'[-/]',x)[1].strip()))
['John Smith - 900 / 2000',
'Bob Foo - 1000 / 2000',
'Bob Foo - 1300 / 2000',
'Bob Foo - 1600 / 2000']
The `sorted` function sort your list based on its key function, and your key
split your elements with `re.split` with function as following :
re.split(r'[-/]',x)
the pattern `[-/]` split your string based on `-` or `/`.
for example :
>>> re.split(r'[-/]',"Bob Foo - 1600 / 2000")
['Bob Foo ', ' 1600 ', ' 2000']
and then you need to `strip()` to remove the leading and trailing spaces. then
convert to int and sort your list based on that value!
|
Ipython notebook 3 disables seaborn settings
Question: I just upgraded to IPython Notebook version 3.0 and it's disabling the
formatting for seaborn. Here's some sample code that replicates the problem
import numpy as np
import matplotlib as mpl
import matplotlib.pyplot as plt
import seaborn as sns
%matplotlib inline
data = np.random.randn(100)
fig,ax = plt.subplots(figsize = (11,8.5))
ax.plot(data)
This code works just fine in IPython Notebook V2.4.1 (see
<http://nbviewer.ipython.org/gist/anonymous/71733c24a68ee464ca40>), but in
IPython Notebook v3.0, the axes become invisible (see
<http://nbviewer.ipython.org/gist/anonymous/7525146b07709206908c>).
Strangely, in V3, when I switch the order of the seaborn import and the
matplotlib inline magic, the plot renders normally the first time I run, then
if I re-run, the axes and gridlines disappear. So it seems to have something
to do with the inline magic disabling seaborn properties.
Any workarounds, other than not re-executing my imports after the first time?
Answer: In iPython Notebook 3.0, add:
seaborn.set_style('darkgrid')
to restore Seaborn default color schemes.
|
Convert CSV to well-structured JSON in Python
Question: I have a CSV file that is structured as below :
`Store, Region, District, MallName, Location`
1234,90,910,MallA,GMT
4567,87,902,MallB,EST
2468,90,811,MallC,PST
1357,87,902,MallD,CST
What I was able to accomplish with my iterative brow-beating was getting a
format like so:
{
"90": {
"910": {
"1234": {
"name": "MallA",
"location": "GMT"
}
},
"811": {
"2468": {
"name": "MallB",
"location": "PST"
}
}
},
"87": {
"902": {
"4567": {
"name": "MallB",
"location": "EST"
},
"1357": {
"name": "MallD",
"location": "CST"
}
}
}
}
The code below is stripped down to match the sample data set I provided but
you get the idea as to what is happening. Again, it's very iterative and non-
pythonic which I'm trying to also move towards. (If anyone feels the defined
procedures would be worthwhile to post I can).
#************
# Main()
#************
dictHierarchy = {}
with open(getFilePath(), 'r') as f:
content = [line.strip('\n') for line in f.readlines()]
for data in content:
data = data.split(",")
myRegion = data[1]
myDistrict = data[2]
myName = data[3]
myLocation = data[4]
myStore = data[0]
if myRegion in dictHierarchy:
#check for District
if myDistrict in dictHierarchy[myRegion]:
#checkforStore
dictHierarchy[myRegion][myDistrict].update({myStore:addStoreDetails(data)})
else:
#add district
dictHierarchy[myRegion].update({myDistrict:addStore(data)})
else:
#add region
dictHierarchy.update({myRegion:addDistrict(data)})
with open('hierarchy.json', 'w') as outfile:
json.dump(dictHierarchy, outfile)
Obsessive compulsive me looked at the JSON output above and thought that to
someone blindly opening the file it looks like a hodge-podge. What I was
hoping to do for plain-text readability is group the data and throw it into
JSON format as so:
{"Regions":[
{"Region":"90", "Districts":[
{"District":"910", "Stores":[
{"Store":"1234", "name":"MallA", "location":"GMT"}]},
{"District":"811", "Stores":[
{"Store":"2468", "name":"MallC", "location":"PST"}]}]},
{"Region":"87", "Districts":[
{"District":"902", "Stores":[
{"Store":"4567", "name":"MallB", "location":"EST"},
{"Store":"1357", "name":"MallD", "location":"CST"}]}]}]}
Long story short I wasted quite some time today trying to sort out how to
actually populate the data structure in Python and essentially ended up no
where. Is there a clean, pythonic way to achieve this? Is it even worth the
effort?
Answer: I've added headers to your input like:
Store,Region,District,name,location
1234,90,910,MallA,GMT
4567,87,902,MallB,EST
2468,90,811,MallC,PST
1357,87,902,MallD,CST
then used python [csv reader](https://docs.python.org/2/library/csv.html) and
[group by](https://docs.python.org/2/library/itertools.html#itertools.groupby)
like this:
import csv
from itertools import groupby, ifilter
from operator import itemgetter
data = []
with open('in.csv') as csvfile:
reader = csv.DictReader(csvfile)
regions = []
regions_dict = sorted(list(reader), key=itemgetter('Region'))
for region_id, region_group in groupby(regions_dict, itemgetter('Region')):
districts = []
regions.append({'Region': region_id, 'Districts': districts})
districts_dict = sorted(region_group, key=itemgetter('District'))
for district_id, district_group in groupby(districts_dict, itemgetter('District')):
districts.append({'District': district_id, 'Stores': list(district_group)})
print regions
|
check entry inputs in tkinter using a function
Question: I trying to create physics calculator using python tkinter but I find it quite
difficult. I have done this calculator in Command line interface but I a bit
different with tkinter. basically, I have 5 entry boxes and above each one of
them a button. the user will insert values in three of them and should press
the button on top of each unknown value to make the calculation and get the
result. my main issue is how can I create a function that evaluates the inputs
in my entry boxes and make the calculation then print the results inside the
entry box. I made some coding but unfortunately the operation is not working
due to few mistakes.
here is my coding part:
from Tkinter import *
import math
class calculator():
def is_positive_number(number): # validation function
if number <= 0:
return False
else :
return True
def value_of_time(prompt):
while True: # loop command for time
try:
valid = False
while not valid:
value = float((prompt))
if is_positive_number(value):
valid = True
return value
else :
valid = False
print ('I donot know what is happening')
except ValueError:
print("Oops, unfortunately this is a wrong input, please try again.")
#better try again... Return to the start of the loop
continue
else:
#value was successfully parsed!
#we're ready to exit the loop.
break
def input_of_box(prompt):
while True: # loop for initial velocity
try:
value = float(input(prompt))
return value
except ValueError:
print("Oops, we are you not typing a number, please try again.")
#better try again... Return to the start of the loop
continue
else:
#value was successfully parsed!
#we're ready to exit the loop.
break
# def minput(numberofinput):
if numberofinput == 1:
t = value_of_time("Enter the time that takes an object to accelerate in seconds:")
return
elif numberofinput == 2:
u = input_of_box("Enter the initial velocity in m/s:")
return
elif numberofinput == 2:
v = input_of_box("Enter the final velocity in m/s:")
return
def my_calculation(mvariables): # this function is to operate the calculation
if mvariables == 1:
a = (v-u) /(t)
mentery1 = a
return
elif mvariables == 2:
v = u + a*t
mentery2 = v
return
elif mvariables == 3:
u = a*t - v
mentery3 = t
elif mvariables == 4:
t = (v - u)/a
mentery3 = t
return
elif mvariables == 5:
s = (v**2-u**2)/2*a
mentery4 = s
else:
print ('there is an error')
cal = Tk()
cal.configure(background='sky blue')
a = StringVar()
u = StringVar()
v = StringVar()
t = StringVar()
s = StringVar()
cal.geometry('650x420+350+225')
cal.title('Main Menu')
# here we start greating buttons and entry boxes
m_label = Label(text='Calculator',fg = 'Navy', font=("Helvetica", 20,"bold italic"), bg='sky blue')
m_label.pack()
button1 = Button(cal,text='A',fg='white',bg='dark green',bd =3, width=4, command= lambda : my_calculation(1))
button1.place(x=92,y=210)
mentery1 = Entry(cal, textvariable = a ,width=10,bd =3)
mentery1.place(x=82,y=240)
button2 = Button(cal,text='U',fg='white',bg='dark green',bd =3, width=4, command= lambda : my_calculation(3))
button2.place(x=192,y=210)
mentery2 = Entry(cal, textvariable = u ,width=10,bd =3)
mentery2.place(x=182,y=240)
button3 = Button(cal,text='V',fg='white',bg='dark green',bd =3, width=4, command= lambda : my_calculation(2))
button3.place(x=292,y=210)
mentery3 = Entry(cal, textvariable = v ,width=10,bd =3)
mentery3.place(x=282,y=240)
button4 = Button(cal,text='T',fg='white',bg='dark green',bd =3, width=4,command= lambda : my_calculation(4))
button4.place(x=392,y=210)
mentery4 = Entry(cal, textvariable = t ,width=10,bd =3)
mentery4.place(x=382,y=240)
button5 = Button(cal,text='S',fg='white',bg='dark green',bd =3, width=4,command= lambda : my_calculation(5))
button5.place(x=492,y=210)
mentery5 = Entry(cal, textvariable = s , width=10,bd =3)
mentery5.place(x=482,y=240)
# end of button commands
app = calculator()
app.mainloop()
Answer: For validating the input, do the following:
def returnValidatedInput(entry):
value = entry.get() # Get the text in the 'entry' widget
evaluation = eval(value) # Evaluate 'value'
return evaluation
And for inserting the answers into the entries (it's not called _printing the
answers into the entries_):
def insertAnswer(entry, answer):
entry.delete(0, 'end') # Be sure the entry is empty, if it is not, clear it
entry.insert(END, str(answer)) # Insert the answer into the 'entry' widget.
|
How to override the .get() method in requests?
Question: I would like the `.get()` method in `requests` to do extra operations beside
the `GET` itself:
* print out "hello world" (in reality this will be logging)
* wait 5 seconds before issuing the actual `GET` (in reality this will be a more complex wait-and-retry operation)
Right now my simplistic solution is to use a function which actually calls
`requests.get()`:
def multiple_requests(self, url, retries=5, wait=5):
"""
retries several times an URL
:param
url: the url to check
retries: how meny times to retry
wait: number of seconds to wait between retries
:return: the requests response, or None if failed
"""
for _ in range(retries):
try:
r = requests.get(url)
except Exception as e:
self.log.error("cannot connect to {url}: {e}, retrying in {wait} seconds".format(url=url, e=e, wait=wait))
else:
if r.ok:
return r
else:
self.log.error(
"error connecting to {url}, code {e}, retrying in {wait} seconds".format(
url=url, e=r.status_code, wait=wait
)
)
finally:
time.sleep(wait)
# give up after several tries
self.log.error("cannot connect to {url} despite retries, giving up".format(url=url))
return None
but I have a strong feeling that it would be possible to override the actual
`.get()` method in requests.
I use object programming in a very basic way and that would be an opportunity
to actually learn the override part. There are
[various](http://blog.devzero.com/2013/01/28/how-to-override-a-class-method-
in-python/) [tutorials](http://lgiordani.com/blog/2014/05/19/method-
overriding-in-python/) on how to override and call the parent class methods
(which is exactly what I want to do: be able to finally use the original
`.get()` method)
I therefore tried a basic override:
import requests
class MyRequest(requests.Request):
def get(self, url, **kwargs):
print("hello world")
# calling the parent .get() method to actually GET something
super(MyRequest, self).get(url, **kwargs)
r = MyRequest.get('http://google.com')
This code fails with
Traceback (most recent call last):
File "C:/Users/yop/dev/infoscreen/testingrequestsclass.py", line 8, in <module>
r = MyRequest.get('http://google.com')
TypeError: get() missing 1 required positional argument: 'url'
To be honest, I am stuck here. The tutorials all start with a definition of
the parent class, while what I have is hidden (there is
[documentation](http://docs.python-requests.org/en/latest/api/))
Answer: [`requests.get` is just a
function](https://github.com/kennethreitz/requests/blob/master/requests/api.py#L57-L65),
you can override it. It is _not_ a method on the `requests.Requests` model:
import requests.api
def my_get(url, **kwargs):
print('Hello World!')
kwargs.setdefault('allow_redirects', True)
return requests.api.request('get', url, **kwargs)
requests.api.get = my_get
This then uses a _new session object_ to handle the request.
Instead of replacing `requests.get()`, I'd provide a subclass of the
`requests.Session()` object instead, overriding the [`Session.request()`
method](https://github.com/kennethreitz/requests/blob/master/requests/sessions.py#L382-L463),
then use an instance of that session object:
from requests import Session
class MySession(Session):
def request(self, method, url, **kwargs):
print('Hello World!')
return super().request(method, url, **kwargs)
then use that like this:
with MySession() as session:
response = session.get(url)
The advantage here is that you then can also make use of the full feature set
that session objects offer, plus your additional code will also work for POST
and PUT and DELETE and HEAD, etc. requests.
|
Django: AttributeError: type object 'MyAppConfig' has no attribute 'rpartition'
Question: I am trying to add `view_amodel` permission to my models. I decided to add the
permission after migration. So I made following approach.
At an_app/**init**.py
from an_app.apps import MyAppConfig
default_app_config = MyAppConfig
At an_app/apps.py
from django.apps import AppConfig
from django.db.models.signals import post_migrate
from django.contrib.contenttypes.models import ContentType
from django.contrib.auth.models import Permission
def add_view_permissions(sender, **kwargs):
"""
This syncdb hooks takes care of adding a view permission too all our
content types.
"""
# for each of our content types
for content_type in ContentType.objects.all():
# build our permission slug
codename = "view_%s" % content_type.model
# if it doesn't exist..
if not Permission.objects.filter(content_type=content_type, codename=codename):
# add it
Permission.objects.create(content_type=content_type,
codename=codename,
name="Can view %s" % content_type.name)
print "Added view permission for %s" % content_type.name
class MyAppConfig(AppConfig):
def ready(self):
post_migrate.connect(add_view_permissions, sender=self)
When I do `python manage.py migrate`, I get following error,
`AttributeError: type object 'MyAppConfig' has no attribute 'rpartition' `
How to solve it.
Answer: The reference to the AppConfig in the app's `__init__.py` is supposed to be a
string, not the class itself.
default_app_config = 'an_app.apps.MyAppConfig'
and remove the import.
See [the
documentation](https://docs.djangoproject.com/en/1.7/ref/applications/#for-
application-authors).
|
Python how to do multiprocessing inside of a class?
Question: I have a code structure that looks like this:
Class A:
def __init__(self):
processes = []
for i in range(1000):
p = Process(target=self.RunProcess, args=i)
processes.append[p]
# Start all processes
[x.start() for x in processes]
def RunProcess(self, i):
do something with i...
Main script:
myA = A()
I can't seem to get this to run. I get a runtime error "**An attempt has been
made to start a new process before the current process has finished its
bootstrapping phase.** "
How do I get multiple processing working for this? If I use Threading, it
works fine but it is as slow as sequential... And I'm also afraid that
multiple processing will also be slow because it takes longer for the the
process to be created?
Any good tips? Many thanks in advance.
Answer: There are a couple of syntax issues that I can see in your code:
* `args` in `Process` expects a tuple, you pass an integer, please change line 5 to:
`p = Process(target=self.RunProcess, args=(i,))`
* `list.append` is a method and arguments passed to it should be enclosed in `()`, not `[]`, please change line 6 to:
`processes.append(p)`
As @qarma points out, its not good practice to start the processes in the
class constructor. I would structure the code as follows (adapting your
example):
import multiprocessing as mp
from time import sleep
class A(object):
def __init__(self, *args, **kwargs):
# do other stuff
pass
def do_something(self, i):
sleep(0.2)
print('%s * %s = %s' % (i, i, i*i))
def run(self):
processes = []
for i in range(1000):
p = mp.Process(target=self.do_something, args=(i,))
processes.append(p)
[x.start() for x in processes]
if __name__ == '__main__':
a = A()
a.run()
|
Issue in reading JSON file in python
Question:
>>> import json
>>> d2 = json.loads(open("t.json").read())
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/lib64/python2.6/json/__init__.py", line 307, in loads
return _default_decoder.decode(s)
File "/usr/lib64/python2.6/json/decoder.py", line 319, in decode
obj, end = self.raw_decode(s, idx=_w(s, 0).end())
File "/usr/lib64/python2.6/json/decoder.py", line 336, in raw_decode
obj, end = self._scanner.iterscan(s, **kw).next()
File "/usr/lib64/python2.6/json/scanner.py", line 55, in iterscan
rval, next_pos = action(m, context)
File "/usr/lib64/python2.6/json/decoder.py", line 185, in JSONObject
raise ValueError(errmsg("Expecting object", s, end))
ValueError: Expecting object: line 1 column 11 (char 11)
[ RHEL - ~/testing ]$ cat t.json
{"us": u"OFF", "val": u"5"}
Here is what I have in my JSON file and when I try to read it using `open` and
`json.load` and json.loads it fails.
After using json.load
>>> import json
>>> d2 = json.load(open("t.json"))
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/lib64/python2.6/json/__init__.py", line 267, in load
parse_constant=parse_constant, **kw)
File "/usr/lib64/python2.6/json/__init__.py", line 307, in loads
return _default_decoder.decode(s)
File "/usr/lib64/python2.6/json/decoder.py", line 319, in decode
obj, end = self.raw_decode(s, idx=_w(s, 0).end())
File "/usr/lib64/python2.6/json/decoder.py", line 336, in raw_decode
obj, end = self._scanner.iterscan(s, **kw).next()
File "/usr/lib64/python2.6/json/scanner.py", line 55, in iterscan
rval, next_pos = action(m, context)
File "/usr/lib64/python2.6/json/decoder.py", line 185, in JSONObject
raise ValueError(errmsg("Expecting object", s, end))
ValueError: Expecting object: line 1 column 11 (char 11)
>>>
Answer: You are using the wrong function. Use `json.load()` (no `s`!) to load data
from an open file object:
d2 = json.load(open("t.json"))
The `json.loads()` function expects you to pass in a _string_ , not a file
object. You'd have to read your file in that case, returning the read data:
d2 = json.loads(open("t.json").read())
Next, you have invalid JSON in that file:
{"us": u"OFF", "val": u"5"}
# ^ ^
JSON is not Python; those `u` prefixes are not supported nor needed. You'll
need to remove those from the file before it'll load.
If you have an API producing that format, it is not giving you JSON. It could
be that it is producing a (strange form of) Python syntax instead; Python
itself would produce `{'us': u'OFF', 'val': u'5'}` (single quotes). You can
have Python interpret that as Python literals with
[`ast.literal_eval()`](https://docs.python.org/2/library/ast.html#ast.literal_eval):
import ast
with open('t.json') as fileobj:
d2 = ast.literal_eval(fileobj.read())
but it could be that the format is broken in other ways we cannot determine
from a single isolated sample. It could be using `true` and `false` for
boolean values, like in JSON, for example.
Better to have the _API_ fixed rather that try and work around this broken-
ness.
|
SQLite select query returns string with a preceeding u in python
Question:
import sqlite3
#connect to the sqlite database
conn = sqlite3.connect('database.db')
#create a cursor
c = conn.cursor()
#select query to return a single row
c.execute('SELECT NAME FROM T1')
#row contains the returned result
row = c.fetchone()
#print the result
print(row)
It prints something like --> `(u'John',)`, but I only want `John`
Answer: You are printing the whole row, which is _always_ going to be a tuple.
If you wanted to print just the first column, use subscription:
print(row[0])
|
In the context of a buildbot master.cfg file, how do I instantiate a class based on a string using native modules
Question: In stock python, I can do the following to instantiate a class based on a
string containing its name:
#!/usr/bin/env python2.7
import sys
class Foo(object): pass
cls = getattr(sys.modules[__name__], 'Foo')
instance = cls()
print repr(instance)
Which outputs the following:
ahammond@af6119›~⁑ ./test.py
<__main__.Foo object at 0x1095b0a10>
I'd like to do something similar inside a buildbot master.cfg file, however
the following (simplified)
class BaseBuild(object): pass
class BuildStashToSrpmsToRpmsToDepot(BaseBuild):
def init(name, build_type):
self.name = name
def setup():
pass # actually does stuff here, but...
for build_name, build_options in config['builds'].iteritems():
cls = getattr(sys.modules[__name__], build_options['build_type'])
build = cls(name=build_name, **build_options)
build.setup()
Produces
2015-03-11 18:39:24-0700 [-] error while parsing config file:
Traceback (most recent call last):
File "/opt/buildbot_virtualenv/lib/python2.7/site-packages/twisted/internet/defer.py", line 577, in _runCallbacks
current.result = callback(current.result, *args, **kw)
File "/opt/buildbot_virtualenv/lib/python2.7/site- packages/twisted/internet/defer.py", line 1155, in gotResult
_inlineCallbacks(r, g, deferred)
File "/opt/buildbot_virtualenv/lib/python2.7/site-packages/twisted/internet/defer.py", line 1099, in _inlineCallbacks
result = g.send(result)
File "/opt/buildbot_git/master/buildbot/master.py", line 189, in startService
self.configFileName)
--- <exception caught here> ---
File "/opt/buildbot_git/master/buildbot/config.py", line 156, in loadConfig
exec f in localDict
File "/home/buildbot/master.cfg", line 208, in <module>
cls = getattr(sys.modules[__name__], build_options['build_type'])
exceptions.AttributeError: 'module' object has no attribute 'BuildStashToSrpmsToRpmsToDepot'
2015-03-11 18:39:24-0700 [-] Configuration Errors:
2015-03-11 18:39:24-0700 [-] error while parsing config file: 'module' object has no attribute 'BuildStashToSrpmsToRpmsToDepot' (traceback in logfile)
Phrased another way, I guess what I'm really asking is what is the temporary
module used while loading a new `master.cfg` and how can I reference it?
I'm currently using a dictionary mapping of { 'class name': class_object } but
I'd prefer something a little more native.
Answer: Your problem here is: When running buildbot, your dunder name (__ name __
without the spaces...) when buildbot exec your config is buildbot.config, this
is why 'module object has no attribute...'.
I think you could do what you want making the values of your build_options
dictionary to be the class itself, not a string with the class name. Like
this:
class BaseBuild(object): pass
class BuildStashToSrpmsToRpmsToDepot(BaseBuild):
def init(name, build_type):
self.name = name
def setup():
pass # actually does stuff here, but...
# here the dict goes with key/class not key/class name
build_options = {'build_type': BuildStashToSrpmsToRpmsToDepot}
for build_name, build_options in config['builds'].iteritems():
cls = build_options['build_type']
build = cls(name=build_name, **build_options)
build.setup()
Just in case, this is how buildbot exec master.cfg (module buildbot.config):
# ...
# execute the config file
localDict = {
'basedir': os.path.expanduser(basedir),
'__file__': os.path.abspath(filename),
}
# from here on out we can batch errors together for the user's
# convenience
global _errors
_errors = errors = ConfigErrors()
old_sys_path = sys.path[:]
sys.path.append(basedir)
try:
try:
exec f in localDict
except ConfigErrors, e:
for err in e.errors:
error(err)
raise errors
except:
log.err(failure.Failure(), 'error while parsing config file:')
error("error while parsing config file: %s (traceback in logfile)" % (sys.exc_info()[1],),)
raise errors
finally:
f.close()
sys.path[:] = old_sys_path
_errors = None
# ...
|
How to implement matlab's ismember(A, b) with A being a numpy ndarray and b being a list
Question: What is the most efficient way to implement matlab's [ismember(A,
b)](http://www.mathworks.com/help/matlab/ref/ismember.html) in python where in
A is any numpy ndarray and b is a list of values. It should return a mask as a
boolean ndarray of the same shape as A where in an element is True if the
corresponding value in A is in the list of values in b.
I want to replace all elements of A with value in list B with something.
I expected `A[A in B] = 0` to work but it throws the following error:
> ValueError: The truth value of an array with more than one element is
> ambiguous. Use a.any() or a.all()
If an implementation of an equivalent of `ismember` is there then the
following would do what I need:
A[ismember(A, b)] = 0
Note: I don't want solutions involving looping through all elements of A in
python.
Based on the answer of [ajcr](http://stackoverflow.com/users/3923281/ajcr),
one solution is:
import numpy as np
def ismember(A, b):
return np.in1d(A, b).reshape(A.shape)
But this is quite slow and runs out of memory. For my case, A is an image as
big as 512 x 512 x 1200. b has about 1000 elements.
Answer: You may be looking for
[`np.in1d`](http://docs.scipy.org/doc/numpy/reference/generated/numpy.in1d.html):
>>> A = np.arange(9)
>>> B = [4, 6, 7]
>>> np.in1d(A, B)
array([False, False, False, False, True, False, True, True, False])
Note that for multidimensional arrays `A`, the input is flattened so you'll
need to reshape the boolean array:
>>> A = np.arange(9).reshape(3, 3)
>>> np.in1d(A, B).reshape(A.shape)
array([[False, False, False],
[False, True, False],
[ True, True, False]], dtype=bool)
|
Extracting data from webpage using lxml XPath in Python
Question: I am having some unknown trouble when using xpath to retrieve text from an
HTML page from lxml library.
The page url is www.mangapanda.com/one-piece/1/1
I want to extract the selected chapter name text from the drop down select
tag. Now I just want the first option so the XPath to find that is pretty
easy. That is :-
.//*[@id='chapterMenu']/option[1]/text()
I verified the above using Firepath and it gives correct data. but when I am
trying to use lxml for the purpose I get not data at all.
from lxml import html
import requests
r = requests.get("http://www.mangapanda.com/one-piece/1/1")
page = html.fromstring(r.text)
name = page.xpath(".//*[@id='chapterMenu']/option[1]/text()")
But in name nothing is stored. I even tried other XPath's like :-
//div/select[@id='chapterMenu']/option[1]/text()
//select[@id='chapterMenu']/option[1]/text()
The above were also verified using FirePath. I am unable to figure out what
could be the problem. I would request some assistance regarding this problem.
But it is not that all aren't working. An xpath that working with lxml xpath
here is :-
.//img[@id='img']/@src
Thank you.
Answer: I've had a look at the html source of that page and the content of the element
with the id `chapterMenu` is empty. I think your problem is that it is filled
using javascript and javascript will not be automatically evaluated just by
reading the html with `lxml.html`
You might want to have a look at this: [Evaluate javascript on a local html
file (without browser)](http://stackoverflow.com/q/16375251/2677943)
Maybe you're able to trick it though... In the end, also javascript needs to
fetch the information using a get request. In this case it requests:
[http://www.mangapanda.com/actions/selector/?id=103&which=191919](http://www.mangapanda.com/actions/selector/?id=103&which=191919)
Which is json and can be easily turned into a python dict/array using the json
library. But you have to find out how to get the `id` and the `which`
parameter if you want to automate this.
The id is part of the html, look for `document['mangaid']` within one of the
script tags and `which` ~~can maybe stay 191919~~ has to be 0... ~~although I
couldn't find it in any source~~ I found it, when it is 0 you will be
redirected to the proper url.
So there you go ;)
|
Pandas HDF5 store unicode error on select query
Question: I have unicode data as read from this file:
Mdt,Doccompra,OrgC,Cen,NumP,Criadopor,Dtcriacao,Fornecedor,P,Fun
400,8751215432,2581,,1,MIGRAÇÃO,01.10.2004,75852214,,TD
400,5464282154,9874,,1,MIGRAÇÃO,01.10.2004,78995411,,FO
I have two problems:
1) When I try to query this unicode data I get the `UnicodeDecodeError`:
Traceback (most recent call last):
File "<ipython-input-1-4423dceb2b1d>", line 1, in <module>
runfile('C:/Users/u5en/Documents/SAP/Programação/Problema HDF.py', wdir='C:/Users/u5en/Documents/SAP/Programação')
File "C:\Users\u5en\AppData\Local\Continuum\Anaconda3\lib\site-packages\spyderlib\widgets\externalshell\sitecustomize.py", line 580, in runfile
execfile(filename, namespace)
File "C:\Users\u5en\AppData\Local\Continuum\Anaconda3\lib\site-packages\spyderlib\widgets\externalshell\sitecustomize.py", line 48, in execfile
exec(compile(open(filename, 'rb').read(), filename, 'exec'), namespace)
File "C:/Users/u5en/Documents/SAP/Programação/Problema HDF.py", line 15, in <module>
store.select("EKKA", "columns=['Mdt', 'Fornecedor']")
File "C:\Users\u5en\AppData\Local\Continuum\Anaconda3\lib\site-packages\pandas\io\pytables.py", line 665, in select
return it.get_result()
File "C:\Users\u5en\AppData\Local\Continuum\Anaconda3\lib\site-packages\pandas\io\pytables.py", line 1359, in get_result
results = self.func(self.start, self.stop, where)
File "C:\Users\u5en\AppData\Local\Continuum\Anaconda3\lib\site-packages\pandas\io\pytables.py", line 658, in func
columns=columns, **kwargs)
File "C:\Users\u5en\AppData\Local\Continuum\Anaconda3\lib\site-packages\pandas\io\pytables.py", line 3968, in read
if not self.read_axes(where=where, **kwargs):
File "C:\Users\u5en\AppData\Local\Continuum\Anaconda3\lib\site-packages\pandas\io\pytables.py", line 3201, in read_axes
a.convert(values, nan_rep=self.nan_rep, encoding=self.encoding)
File "C:\Users\u5en\AppData\Local\Continuum\Anaconda3\lib\site-packages\pandas\io\pytables.py", line 2058, in convert
self.data, nan_rep=nan_rep, encoding=encoding)
File "C:\Users\u5en\AppData\Local\Continuum\Anaconda3\lib\site-packages\pandas\io\pytables.py", line 4359, in _unconvert_string_array
data = f(data)
File "C:\Users\u5en\AppData\Local\Continuum\Anaconda3\lib\site-packages\numpy\lib\function_base.py", line 1700, in __call__
return self._vectorize_call(func=func, args=vargs)
File "C:\Users\u5en\AppData\Local\Continuum\Anaconda3\lib\site-packages\numpy\lib\function_base.py", line 1769, in _vectorize_call
outputs = ufunc(*inputs)
File "C:\Users\u5en\AppData\Local\Continuum\Anaconda3\lib\site-packages\pandas\io\pytables.py", line 4358, in <lambda>
f = np.vectorize(lambda x: x.decode(encoding), otypes=[np.object])
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xc3 in position 7: unexpected end of data
How can I _store_ and _query_ my unicode data in hdf5?
2) I have many tables with column names I do not know beforehand and which are
not propper pytable names (NaturalNameWarning). I would like the user to be
able to query on this columns, so I wonder how could I query these when their
name prevents me. I see this used to have [no easy
fix](http://%20http://stackoverflow.com/questions/19277059/pandas-hdf5-select-
with-where-on-non-natural-named-columns), so if that is still the case I will
just remove the offending characters from the heading.
import csv
import pandas as pd
dados = pd.read_csv("EKKA - Cópia.csv")
print(dados)
store= pd.HDFStore('teste.h5' , encoding="utf-8")
store.append("EKKA", dados, format="table", data_columns=True)
store.select("EKKA", "columns=['Mdt', 'Fornecedor']")
store.close()
Would I be _better off_ doing this in _sqlite_?
Environment: Windows 7 64bit Pandas 15.2 NumPy 1.9.2
Answer: So under Python 2.7 on Windows 7, pandas 0.15.2, everything worked as
expected, no encoding necessary. However on Python 3.4, the following worked
for me. Apparently some characters are not representable in 'utf-8'; 'latin1'
encoding usually solves these issues. Note that I had to read the csv in the
first place with this encoding.
>>> df = pd.read_csv('../../test.csv',encoding='latin1')
>>> df
Mdt Doccompra OrgC Cen NumP Criadopor Dtcriacao Fornecedor P Fun
0 400 8751215432 2581 NaN 1 MIGRAÇ\xc3O 01.10.2004 75852214 NaN TD
1 400 5464282154 9874 NaN 1 MIGRAÇ\xc3O 01.10.2004 78995411 NaN FO
Further, the encoding must be specified not when opening the store, but on the
`append/put` calls
>>> df.to_hdf('test.h5','df',format='table',mode='w',data_columns=True,encoding='latin1')
>>> pd.read_hdf('test.h5','df')
Mdt Doccompra OrgC Cen NumP Criadopor Dtcriacao Fornecedor P Fun
0 400 8751215432 2581 NaN 1 MIGRAÇ\xc3O 01.10.2004 75852214 NaN TD
1 400 5464282154 9874 NaN 1 MIGRAÇ\xc3O 01.10.2004 78995411 NaN FO
Once it is written encoded, it is not necessary to specify the encoding when
reading.
|
Python: assert call to a list that contains a variable
Question: This question follows python 2.7.3 syntax. In unittest framework, suppose I
have the following set up:
import mock;
my_mock = mock.Mock();
my_patch = mock.patch("my_method", my_mock);
Now suppose my_method takes on a list argument as input.
How Can I use my_mock.assert_any_call to make sure that a call is made to
my_method such that the input list contains a particular value?
Answer: You can do that by use both
[`mock_calls`](https://docs.python.org/3/library/unittest.mock.html#unittest.mock.Mock.mock_calls)
and call unpacking as documented
[here](https://docs.python.org/3/library/unittest.mock.html#call). Now a for
cycle can be enough to do the work:
>>> import mock
>>> m = mock.Mock()
>>> m([1,2])
<Mock name='mock()' id='140596484020816'>
>>> m([5,6])
<Mock name='mock()' id='140596484020816'>
>>> m([8,9])
<Mock name='mock()' id='140596484020816'>
>>> for name,args,kwrgs in m.mock_calls:
... if 5 in args[0]:
... print("found")
...
found
|
Selenium Connection Error
Question: Has anyone run across this error before? I just started getting this error on
monday. Why is it having issues with connecting?
Selenium will open the browser but will not plug in the url.
C:\Python34\python.exe "C:\Program Files (x86)\JetBrains\PyCharm Community Edition 4.0.5\helpers\pydev\pydevd.py" --multiproc --client 127.0.0.1 --port 49660 --file //HAL1/FTP-Directories/Comal-County/comal.py
pydev debugger: process 5564 is connecting
Connected to pydev debugger (build 139.1547)
Traceback (most recent call last):
File "C:\Program Files (x86)\JetBrains\PyCharm Community Edition 4.0.5\helpers\pydev\pydevd.py", line 2217, in <module>
globals = debugger.run(setup['file'], None, None)
File "C:\Program Files (x86)\JetBrains\PyCharm Community Edition 4.0.5\helpers\pydev\pydevd.py", line 1643, in run
pydev_imports.execfile(file, globals, locals) # execute the script
File "C:\Program Files (x86)\JetBrains\PyCharm Community Edition4.0.5\helpers\pydev\_pydev_imps\_pydev_execfile.py", line 18, in execfile
exec(compile(contents+"\n", file, 'exec'), glob, loc)
File "//HAL1/FTP-Directories/Comal-County/comal.py", line 7, in <module>
driver = webdriver.Firefox();
File "C:\Python34\lib\site-packages\selenium\webdriver\firefox\webdriver.py", line 59, in __init__
self.binary, timeout),
File "C:\Python34\lib\site-packages\selenium\webdriver\firefox\extension_connection.py", line 47, in __init__
self.binary.launch_browser(self.profile)
File "C:\Python34\lib\site-packages\selenium\webdriver\firefox\firefox_binary.py", line 66, in launch_browser
self._wait_until_connectable()
File "C:\Python34\lib\site-packages\selenium\webdriver\firefox\firefox_binary.py", line 105, in _wait_until_connectable
raise WebDriverException("Can't load the profile. Profile "
selenium.common.exceptions.WebDriverException: Message: Can't load the profile. Profile Dir: %s If you specified a log_file in the FirefoxBinary constructor, check it for details.
Code:
from selenium import webdriver
driver = webdriver.Firefox();
driver.get("http://www.google.com")
Answer: This is a **compatibility issue** between `selenium` and `Firefox`.
Upgrade your `Firefox` to the latest version (36 at the moment).
And upgrade `selenium` to the latest version (2.45 at the moment):
pip install --upgrade selenium
|
How to create a combobox that includes checkbox for each item?
Question: Fairly new to tkinter and python I was wondering how to achieve a button that
would act like this :
* Click on button drops down a list (so that's a combobox)
* Each line of the list has a checkbox.
* Finally if a checkbox is clicked run a function, or (even better) once combobox is no more dropped run a function with items checked as args.
**UPDATE**
The button/menuButton will have to act like a filter. When menu is dropped
down user can uncheck multiple options (without the menu to disappear each
time an item is clicked) he don't want. Therefore it's really important to be
able to see checkboxes so as the user know which options are currently active.
I finally used the idea of Bryan by creating a top level frame. Here is what I
have :
Answer: I don't think the `OptionMenu` is intended to hold anything but strings. It
sounds like you want the functionality of a
[Listbox](http://effbot.org/tkinterbook/listbox.htm), which has options to
allow for multiple selections, get all selected items, and so on.
This gives you an `OptionMenu` with _checkboxes_ in the contained Menu. Check
whichever items you like, then right-click in the tkinter window to print the
values of the checkboxes to the console.
from tkinter import *
master = Tk()
var = StringVar(master)
var.set("Check")
w = OptionMenu(master, variable = var, value="options:")
w.pack()
first = BooleanVar()
second = BooleanVar()
third = BooleanVar()
w['menu'].add_checkbutton(label="First", onvalue=True,
offvalue=False, variable=first)
w['menu'].add_checkbutton(label="Second", onvalue=True,
offvalue=False, variable=second)
w['menu'].add_checkbutton(label="Third", onvalue=1,
offvalue=False, variable=third)
master.bind('<Button-3>', lambda x: print("First:", first.get(), " Second:",
second.get(), " - Third:", third.get()))
mainloop()
See also [this](http://stackoverflow.com/questions/3929355/making-menu-
options-with-checkbutton-in-tkinter-python).
|
Using predict() on statsmodels.formula data with different column names using Python and Pandas
Question: I've got some regressions results from running `statsmodels.formula.api.ols`.
Here's a toy example:
import pandas as pd
import numpy as np
import statsmodels.formula.api as smf
example_df = pd.DataFrame(np.random.randn(10, 3))
example_df.columns = ["a", "b", "c"]
fit = smf.ols('a ~ b', example_df).fit()
I'd like to apply the model to column `c`, but a naive attempt to do so
doesn't work:
fit.predict(example_df["c"])
Here's the exception I get:
PatsyError: Error evaluating factor: NameError: name 'b' is not defined
a ~ b
^
I can do something gross and create a new, temporary `DataFrame` in which I
rename the column of interest:
example_df2 = pd.DataFrame(example_df["c"])
example_df2.columns = ["b"]
fit.predict(example_df2)
Is there a cleaner way to do this? (short of switching to `statsmodels.api`
instead of `statsmodels.formula.api`)
Answer: You can use a dictionary:
>>> fit.predict({"b": example_df["c"]})
array([ 0.84770672, -0.35968269, 1.19592387, -0.77487812, -0.98805215,
0.90584753, -0.15258093, 1.53721494, -0.26973941, 1.23996892])
or create a numpy array for the prediction, although that is much more
complicated if there are categorical explanatory variables:
>>> fit.predict(sm.add_constant(example_df["c"].values), transform=False)
array([ 0.84770672, -0.35968269, 1.19592387, -0.77487812, -0.98805215,
0.90584753, -0.15258093, 1.53721494, -0.26973941, 1.23996892])
|
Running remote command with fabric doesn't separate stdout and stderr streams
Question: I have a python file like so in my home directory
import sys
sys.stdout.write('THIS IS STDOUT\n')
sys.stdout.flush()
sys.stderr.write('THIS IS STDERR\n')
sys.stderr.flush()
When I run this python file, I get output to stdout/stderr as expected.
Now, I have the following fabfile:
from fabric.api import run, task
@task
def my_task(cmd):
run(cmd)
When I run the task, both lines get reported as coming from stdout:
$ fab --host localhost my_task:'python foo.py'
[localhost] Executing task 'my_task'
[localhost] run: python foo.py
[localhost] out: THIS IS STDOUT
[localhost] out: THIS IS STDERR
[localhost] out:
Done.
Disconnecting from localhost... done.
Why does fabric pipe stderr into stdout? Looking
[here](https://github.com/fabric/fabric/blob/master/fabric/io.py#L44) stderr
lines should get `err:` prepended to them, not `out`. Moreover, adding some
debugging statements in there I can see that there is an object set up to
watch `stderr`; however it's just not getting any data. Is there a way to
change this so that the error lines get `err:` in front of them?
Answer: Just disable `combine_stderr`:
run(cmd, combine_stderr=False)
|
Is there a way to test correlation between Data X and Binary output Y?
Question: I'm trying to find a Python method/library for testing correlation between the
independent variables X and the binary output Y..
So for example, lets say I have the following data and output:
**X** **Y**
0.65 1
0.11 0
0.13 0
0.35 1
0.21 0
...
Lets say the output Y is 1 if (X > 0.3) and 0 otherwise. If I don't know this
correlation (the threshold value 0.3), is there a statistical method/test to
find out the degree of correlation between X and Y?
So for example, some method that returns
x = [0.65, 0.11, 0.13, 0.31, 0.21]
y = [1, 0, 0, 1, 0]
print some_test(x, y)
==> returns "degree of correlation = 1.0"
Thanks
Answer: You are looking for a [point biserial
correlation](http://en.wikipedia.org/wiki/Point-
biserial_correlation_coefficient), which is used when one of your variables is
dichotomous.
from scipy import stats
stats.pointbiserialr(x,y)
If you simply want to know whether X is _different_ depending on the value of
Y, you should instead use a t-test.
|
interpreting bytes as ushorts in Python
Question: I need to interpret 16 bytes received over a TCP socket as 8 ushorts.
This line correctly receives the data (the 16-bit values of 8 a-d converters),
and I can access each byte as an index into a byte array:
vals = bytearray(s.recv(16))
And I could create 8 variables and decode each:
ad1 = (ord(vals[0]) * 256)+ord(vals[1])
But it would be more elegant if I could recast this array as 8 ushorts.
I have tried many variations of struct.unpack, with just as many syntax
errors. My background is in C, so I would ordinarily use a union or recast a
byte pointer, but...
can anyone point me in the right direction? thanks, and my apologies if this
has been asked before.
#
here is the full monty:
import socket,struct,time
import xrlib
def readADx(socket,a2dnumber):
# a2dnumber 1 - 8
if a2dnumber < 1 or a2dnumber > 8:
return 0
a2d = a2dnumber + 0x9D
tdata = struct.pack('BB',0xFE,a2d)
s.send(tdata)
val = ord(s.recv(1)) * 256
val = val + ord(s.recv(1))
return val
#
# define TCP client socket:
#
IPADDR = '192.168.99.9'
PORTNUM = 2101
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((IPADDR,PORTNUM))
tdata = struct.pack('BB',0xFE,0xA7)
s.send(tdata)
#
# the problem:
#
vals = bytearray(s.recv(16))
adv = struct.unpack('8H',vals)
#
# get the true values for A/D 7 and 8:
#
ad8 = readADx(s,8);
ad7 = readADx(s,7);
s.close()
print("%04X %04X %04X %04X %04X %04X %04X %04X"%adv[0],adv[1],adv[2],adv[3],adv[4],adv[5],adv[6],adv[7]))
print("AD8: %d"%(ad8));
print("AD7: %d"%(ad7));
print("adv[7]: %d"%(adv[7]));
print("adv[6]: %d"%(adv[6]));
running this gives this error:
struct.error: unpack requires a string argument of length 16
this is the error I would invariably get, with different argument lengths.
this code works:
adv = struct.unpack('8H',s.recv(16))
but the byte order of each reading (adv[x]) is reversed. I found
socket.ntohs() to fix this.
Still not sure why the struct.unpack would not work with the bytearray arg...
Answer: (transforming a comment to an answer)
ad1 = struct.unpack('8H', vals)
|
How can I monitor a TCP port for packets and timeout if none is received?
Question: I'm creating a test client with using python to test my server. It sends TCP
data packets to a server, which _should_ send back 1 response to the client in
the same TCP connection. If it does not send any response, or sends more than
1 response, then I have a bug in the server code.
What I want to do is to monitor the TCP port for response message(s) and print
them out. If there is no response, the script should carry on execution after
a timeout.
Here's the relevant code:
import socket
import time
import multiprocessing
def get_response(response_stream, response_buffer_size):
response_count = 1
while True:
response = response_stream.recv(response_buffer_size).decode()
print("[response]", response_count, ":", response)
response_count += 1
TCP_IP = '192.168.1.101'
TCP_PORT = 12345
BUFFER_SIZE = 1024
MESSAGE = b"Bazinga!"
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((TCP_IP, TCP_PORT))
s.send(MESSAGE.encode())
print("Message sent.")
p = multiprocessing.Process(target = get_response(s,BUFFER_SIZE))
p.start()
p.join(3)
if p.is_alive():
print("Killing thread ...")
p.terminate()
p.join()
s.close()
print("Socket closed.")
So it turns out that `p.join(3)` is never reached because the code is stuck
inside `get_response` at this line : `response =
response_stream.recv(response_buffer_size).decode()`.
The script will always wait there to decode the next packet, hence the script
never terminates properly. What am I doing wrong ?
Answer: First, this line:
p = multiprocessing.Process(target = get_response(s,BUFFER_SIZE))
Is actually calling `get_response` _on the main thread_. Since, you're not
passing a function name like you should, but calling the function and passing
the `target` argument, the result of that call.
Instead you want
p = multiprocessing.Process(target=get_response, args=(s,BUFFER_SIZE))
**But this won't work!** You can't easily pass a socket to a different
process. There are ways around it with pipes, but the implementation is only
there for Unix or Python3 on Windows.
So consider the different approach I list below.
Third, you might want to add something that breaks out of the infinite loop
inside your child process function. I added a line to check if `recv` returned
an empty string, you could modify it to your liking.
Consider:
import socket
import time
import multiprocessing
def worker(tcp_ip, tcp_port, response_buffer_size):
MESSAGE = b"Bazinga!"
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((tcp_ip, tcp_port))
s.send(MESSAGE.encode())
print("Message sent.")
response_count = 1
while True:
response = s.recv(response_buffer_size).decode()
if len(response) == 0: break
print("[response]", response_count, ":", response)
response_count += 1
# If we got here, the connection was closed
s.close()
print("Socket closed.")
if __name__ == "__main__":
TCP_IP = '192.168.1.10'
TCP_PORT = 12345
BUFFER_SIZE = 1024
p = multiprocessing.Process(target=worker, args=(TCP_IP, TCP_PORT, BUFFER_SIZE))
p.start()
p.join(3)
if p.is_alive():
print("Killing thread ...")
p.terminate()
p.join()
print("Thread terminated.")
print("Goodbye.")
Here, we put _all_ socket activity in the worker thread. It owns and opens the
socket, sends the "Bazinga" and handles responses.
|
Error writing text into a .txt file in python
Question: I am making a program that will 1\. Create a text file 2\. Allow a password to
be stored 3\. Allow a password to be changed 4\. Add an additional password
5\. Delete a specific password The problem is in `def delete():`. I put in
three passwords on three seperate lines: first, second, third. When I choose
to delete password "second", it reprints the list from before, and then prints
the new list at the end of the last password.
Here is my code:
import time
def create():
file = open("password.txt", "w")
passwordOfChoice = input("The password you want to store is: ")
file.write(passwordOfChoice)
print ("Your password is: ", passwordOfChoice)
file.close()
time.sleep(2)
def view():
file = open("password.txt","r")
print ("Your password is: ",
"\n", file.read())
file.close()
time.sleep(2)
def change():
file = open("password.txt", "w")
newPassword = input("Please enter the updated password: ")
file.write(newPassword)
print ("Your new password is: ", newPassword)
file.close()
time.sleep(2)
def add():
file = open("password.txt", "a")
extraPassword = input("The password you want to add to storage is: ")
file.write("\n")
file.write(extraPassword)
print ("The password you just stored is: ", extraPassword)
file.close()
time.sleep(2)
def delete():
phrase = input("Enter a password you wish to remove: ")
f = open("password.txt", "r+")
lines = f.readlines()
for line in lines:
if line != phrase+"\n":
f.write(line)
f.close()
print("Are you trying to: ",
"\n1. Create a password?",
"\n2. View a password?",
"\n3. Change a previous password?",
"\n4. Add a password?",
"\n5. Delete a password?",
"\n6. Exit?\n")
function = input()
print("")
if (function == '1'):
create()
elif (function == '2'):
view()
elif (function == '3'):
change()
elif (function == '4'):
add()
elif (function == '5'):
delete()
elif (function == '6'):
print("Understood.", "\nProgram shutting down.")
time.sleep(1)
else:
print("Your answer was not valid.")
print("Program shutting down...")
time.sleep(1)
To show what I meant above, here is my output:
Your password is:
first
second
thirdfirst
third
Can someone please tell me how to fix my `def delete():` function so that it
will not rewrite the original data? Thanks a ton!
Answer: The problem lies with the 'r+' mode. When you use 'r+' you can read and write,
sure, but it's up to you to control _where_ in the file you write. What's
happening is you read the file, and the cursor is stuck at the end, so when
you write it back, Python dutifully puts your new lines on the end of the
file. See [the
docs](https://docs.python.org/3.4/tutorial/inputoutput.html#methods-of-file-
objects) about file methods; you're looking for something like **seek**.
|
how do you access rows in tables in html form usibg python mechanize
Question: im trying to access the rows in an html form, the html code in the form is as
such
</script>
<form name="calendarForm" method="post" action="/ibook/publicLogin.do" onsubmit="return validateForm(this);"><div><input type="hidden" name="org.apache.struts.taglib.html.TOKEN" value="7a6aa28270cc38601c894a05d01b7264"></div>
<input type="hidden" name="apptDetails.apptType" value="PRAP">
<table border="0" cellspacing="1" cellpadding="0" align="center">
<tr>
<td nowrap="nowrap" width="20%"><div id=id_div1 style="display:''"><FONT color=#ff0000>*</FONT><label for="apptDetails.identifier1">Sponsor's NRIC /<br /> Applicant's FIN</label></div></td>
<td nowrap="nowrap" width="5%">:</td>
<td nowrap="nowrap" width="75%"><div id=id_div3 style="display:''"><input type="text" name="apptDetails.identifier1" maxlength="9" size="15" value="" onblur="javascript:this.value=this.value.toUpperCase();" id="apptDetails.identifier1" style="text-transform: uppercase;" class="txtFill_singleLine"></div></td>
</tr>
im tring to add information to row with name `name="apptDetails.identifier1" `
how do i input values to the row? i dont seem to be able to access the html
row using conventional python mechanize form options please advise
here is my code
import cookielib
import urllib2
import mechanize
# Browser
br = mechanize.Browser()
# Enable cookie support for urllib2
cookiejar = cookielib.LWPCookieJar()
br.set_cookiejar( cookiejar )
# Broser options
br.set_handle_equiv( True )
br.set_handle_gzip( True )
br.set_handle_redirect( True )
br.set_handle_referer( True )
br.set_handle_robots( False )
# ??
br.set_handle_refresh( mechanize._http.HTTPRefreshProcessor(), max_time = 1 )
br.addheaders = [ ( 'User-agent', 'Mozilla/5.0 (Windows NT 6.1; WOW64; rv:35.0) Gecko/20100101 Firefox/35.0' ),('Host','eappointment.ica.gov.sg'),('Accept','text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8') ]
# authenticate
br.open('https://eappointment.ica.gov.sg/ibook/gethome.do')
print "forms"
br.select_form(name="calendarForm")
print "forms"
# these two come from the code you posted
# where you would normally put in your username and password
br.find_control(name="apptDetails.apptType").value = ['PRAP']
res = br.submit()
html = br.response().readlines()
file = open("html.txt", "w")
for i in range(0, len(html)):
file.write(html[i])
file.write('\n')
file.close()
br.close()
print "Success!\n"
Answer: After calling `br.submit()`, you will have navigated to the next page. There
are _two_ forms on that page, _both_ named "calendarForm":
>>> for f in br.forms():
... print f
... print
...
<calendarForm POST https://eappointment.ica.gov.sg/ibook/loginSelection.do application/x-www-form-urlencoded
<HiddenControl(org.apache.struts.taglib.html.TOKEN=2eb104ffed4bc6ea09b67e556e5dd6e2) (readonly)>
<SelectControl(apptDetails.apptType=[CS, CSCA, CSCR, CSIC, CSPC, CSXX, PR, *PRAP, PRCF, PRAR, PRIC, PRNN, PRTR, CSXX, VS, VSEI, VSLA, VSLT, VSSP, VSST, VSVP])>>
<calendarForm POST https://eappointment.ica.gov.sg/ibook/publicLogin.do application/x-www-form-urlencoded
<HiddenControl(org.apache.struts.taglib.html.TOKEN=2eb104ffed4bc6ea09b67e556e5dd6e2) (readonly)>
<HiddenControl(apptDetails.apptType=PRAP) (readonly)>
<TextControl(apptDetails.identifier1=)>
<TextControl(apptDetails.identifier2=)>
<TextControl(apptDetails.identifier3=)>
<IgnoreControl(Clear=<None>)>>
You need to select the second form (with index 1), so:
>>> br.select_form(nr=1)
>>> print br.form
<calendarForm POST https://eappointment.ica.gov.sg/ibook/publicLogin.do application/x-www-form-urlencoded
<HiddenControl(org.apache.struts.taglib.html.TOKEN=2eb104ffed4bc6ea09b67e556e5dd6e2) (readonly)>
<HiddenControl(apptDetails.apptType=PRAP) (readonly)>
<TextControl(apptDetails.identifier1=)>
<TextControl(apptDetails.identifier2=)>
<TextControl(apptDetails.identifier3=)>
<IgnoreControl(Clear=<None>)>>
Now you can fill in the form's fields:
>>> br.form['apptDetails.identifier1'] = '12345'
>>> br.form['apptDetails.identifier2'] = '99'
>>> br.form['apptDetails.identifier3'] = '911'
>>> print br.form
<calendarForm POST https://eappointment.ica.gov.sg/ibook/publicLogin.do application/x-www-form-urlencoded
<HiddenControl(org.apache.struts.taglib.html.TOKEN=2eb104ffed4bc6ea09b67e556e5dd6e2) (readonly)>
<HiddenControl(apptDetails.apptType=PRAP) (readonly)>
<TextControl(apptDetails.identifier1=12345)>
<TextControl(apptDetails.identifier2=99)>
<TextControl(apptDetails.identifier3=911)>
<IgnoreControl(Clear=<None>)>>
and, finally, submit and save the response for inspection:
>>> br.submit()
>>> open('response.html', 'w').write(br.response().read())
If you entered valid values for the 3 identifiers, you should be at the next
page, whatever that is.
|
Python2: subprocess.Popen() has another output as it runs direct on console
Question: When i am running a program in the console, i get some text output. When i am
running the same program in Popen(..), with the same parameters, stdout and
stderr are empty.
I tried everything i could imagine like shell=False and shell=True, set
stdout=subprocess.PIPE, did a os.chdir() to change into the directory of this
program, try p.wait() and p.communicate(), set the command as a list and as a
string, but nothing works.
example:
p = subprocess.Popen(command, shell=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE, stdin=subprocess.PIPE)
out, err = p.communicate()
\--> out and err are empty strings, but if i ran this command in console i get
a real output. Command is with fullpath, so its regardless where the command
will be started.
My question is, are there mechanisms for programms to detect they weren't run
in a real console? If so, how can i cheat.
Or miss i something?
(Python 2.7.8. x32 in Win7 x64)
Answer:
from subprocess import Popen, STDOUT, PIPE
p = Popen(command, shell=True, stdout=PIPE, stderr=STDOUT, stdin=PIPE)
while p.poll() is None:
print(p.stdout.read())
p.stdout.close()
p.stdin.close()
Try this and see if it makes any difference. Also make sure `command` is a
string and not a list/touple, `shell=True` for whatever reason works better or
only with strings. Also note that `shell=True` will get you hanged because
it's insecure etc.
Also skipping `.communicate()` you'll need to tap off `stdout` otherwise the
buffer will get full and you might hang both yours and the child process.
* * *
_If this doesn't work, please provide more information. Such as the command
used and the expected output (at least first few lines)_
|
Using GPXPY to parse gpx file results in not well-formed invalid token error
Question: I have a few gpx files which I want to parse and then feed into a GIS format.
I've downloaded [gpxpy](https://pypi.python.org/pypi/gpxpy/0.9.8) because I
need some of its functions rather than just wanting to extract the lat and lon
from the files. But when I make a parser
import gpxpy
p = gpxpy.parse(path_to_gpx_file)
it gives me this:
ERROR:root:not well-formed (invalid token): line 1, column 2
Traceback (most recent call last):
File "C:\Python26\ArcGIS10.0\lib\site-packages\gpxpy\parser.py", line 196, in parse
self.xml_parser = XMLParser(self.xml)
File "C:\Python26\ArcGIS10.0\lib\site-packages\gpxpy\parser.py", line 43, in __init__
self.dom = mod_minidom.parseString(xml)
File "C:\Python26\ArcGIS10.0\lib\xml\dom\minidom.py", line 1928, in parseString
return expatbuilder.parseString(string)
File "C:\Python26\ArcGIS10.0\lib\xml\dom\expatbuilder.py", line 940, in parseString
return builder.parseString(string)
File "C:\Python26\ArcGIS10.0\lib\xml\dom\expatbuilder.py", line 223, in parseString
parser.Parse(string, True)
ExpatError: not well-formed (invalid token): line 1, column 2
Traceback (most recent call last):
File "<input>", line 1, in <module>
File "C:\Python26\ArcGIS10.0\lib\site-packages\gpxpy\__init__.py", line 32, in parse
return parser.parse()
File "C:\Python26\ArcGIS10.0\lib\site-packages\gpxpy\parser.py", line 219, in parse
raise mod_gpx.GPXXMLSyntaxException('Error parsing XML: %s' % str(e), e)
GPXXMLSyntaxException: Error parsing XML: not well-formed (invalid token): line 1, column 2
After spending some time googling, this lead me to suspect that there are
errors in the xml structure. However, I can't spot them.
I've used <http://www.validome.org/xml/validate/> to validate the files but it
says they're valid.
This is what my gpx files look like. I've reduced this one to include only 3
trackpoints, but it's still giving me the same error as the full (35k
lines)file.
<?xml version="1.0" encoding="UTF-8" standalone="no" ?>
<gpx xmlns="http://www.topografix.com/GPX/1/1"
xmlns:gpxx="http://www.garmin.com/xmlschemas/GpxExtensions/v3"
xmlns:wptx1="http://www.garmin.com/xmlschemas/WaypointExtension/v1"
xmlns:gpxtpx="http://www.garmin.com/xmlschemas/TrackPointExtension/v1"
creator="Dakota 20" version="1.1"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.topografix.com/GPX/1/1 http://www.topografix.com/GPX/1/1/gpx.xsd http://www.garmin.com/xmlschemas/GpxExtensions/v3 http://www8.garmin.com/xmlschemas/GpxExtensionsv3.xsd http://www.garmin.com/xmlschemas/WaypointExtension/v1 http://www8.garmin.com/xmlschemas/WaypointExtensionv1.xsd http://www.garmin.com/xmlschemas/TrackPointExtension/v1 http://www.garmin.com/xmlschemas/TrackPointExtensionv1.xsd">
<metadata>
<link href="http://www.garmin.com">
<text>Garmin International</text>
</link>
<time>2015-03-01T16:59:53Z</time>
</metadata>
<trk>
<name>SKI1</name>
<extensions>
<gpxx:TrackExtension></gpxx:TrackExtension>
</extensions>
<trkseg>
<trkpt lat="43.3737357836" lon="130.0217922572">
<ele>166.26</ele>
<time>2015-03-01T08:34:40Z</time>
</trkpt>
<trkpt lat="43.3737673834" lon="130.0218102783">
<ele>166.22</ele>
<time>2015-03-01T08:34:42Z</time>
</trkpt>
<trkpt lat="43.3737869971" lon="130.0217925087">
<ele>166.78</ele>
<time>2015-03-01T08:35:02Z</time>
</trkpt>
</trkseg>
</trk>
</gpx>
EDIT maybe should add: using python 2.6, gpxpy 0.9.8, pycharm 3.1.1
Answer: It isn't really documented anywhere (in my opinion), so I'll post it here.
Instead of letting the parser try to open the file, generate a file object
first, and feed that to the parser, so:
import gpxpy
f = open(path_to_gpx_file, 'r')
p = gpxpy.parse(f)
I don't know why I didn't try that before...
|
Can I use SQL to split contents of a table column stored as CSV (comma seperated values) into individual rows in a new table?
Question: I see there are a couple of related questions with answers, but not exactly
what I need, so I'll ask a new question. I have this CSV file with thousands
of rows of store inventories data which I'd like to import into a MS SQL
Server database and use SQL to process them. After importing the CSV file, the
SQL table will have three columns that contain CSV data. The problem is that I
need to get this CSV data into individual rows in order to analyze it more.
I'd like to end up with two tables in the end: the original table created by
the import of the CSV file, and a table created by splitting out the CSV. Here
is a representation of what the two tables would look like:
/Table1 (the original CSV file). First row is column names:
StoreID,Date,StoreName,City,State,Category1CSV,Category2CSV,Category3CSV
1051,2/16/2014,Easton,Columbus,OH,"Flour,Yeast,Baking Powder","Milk,Water,Oil","Cinnamon,Sugar"
1425,1/14/2014,Crocker Park,Westlake,OH,"Baking Powder,Yeast,Flour","Oil,Milk,Water","Rosemay,Cinnamon,Sugar"
/Table2 (after splitting the CSV column contents). First row is column names:
StoreID,Date,StoreName,City,State,ItemName,ItemRank,ItemCategory
1051,2/16/2014,Easton,Columbus,OH,Flour,1,1
1051,2/16/2014,Easton,Columbus,OH,Yeast,2,1
1051,2/16/2014,Easton,Columbus,OH,Baking Powder,3,1
1051,2/16/2014,Easton,Columbus,OH,Milk,4,2
1051,2/16/2014,Easton,Columbus,OH,Water,5,2
1051,2/16/2014,Easton,Columbus,OH,Oil,6,2
1051,2/16/2014,Easton,Columbus,OH,Cinnamon,7,3
1051,2/16/2014,Easton,Columbus,OH,Sugar,8,3
1425,1/14/2014,Crocker Park,Westlake,OH,Baking Powder,1,1
1425,1/14/2014,Crocker Park,Westlake,OH,Yeast,2,1
1425,1/14/2014,Crocker Park,Westlake,OH,Flour,3,1
1425,1/14/2014,Crocker Park,Westlake,OH,Oil,4,2
1425,1/14/2014,Crocker Park,Westlake,OH,Milk,5,2
1425,1/14/2014,Crocker Park,Westlake,OH,Water,6,2
1425,1/14/2014,Crocker Park,Westlake,OH,Rosemary,7,3
1425,1/14/2014,Crocker Park,Westlake,OH,Cinnamon,8,3
1425,1/14/2014,Crocker Park,Westlake,OH,Sugar,9,3
The SQL column data types are:
Table 1
StoreID - int
Date - date
StoreName - nvarchar(50)
City- nvarchar(50)
State- nvarchar(50)
Category1CSV - nvarchar(MAX)
Category2CSV - nvarchar(MAX)
Category3CSV - nvarchar(MAX)
Table2
StoreID - int
Date - date
StoreName - nvarchar(50)
City- nvarchar(50)
State - nvarchar(50)
ItemName - nvarchar(50)
ItemRank - tinyint
ItemCategory -tinyint
The Table 1 columns labeled Category1CSV, Category2CSV, and Category3CSV
contents map to Table 2 columns: ItemName, ItemRank, ItemCategory, where
ItemName is the Item (example: Flour), ItemRank is the order of the item in
the CSV list, and ItemCategory is either 1,2 or 3, depending on whether the
data came from Category1CSV, Category2CSV or Category3CSV.
The most important aspect of this (other than splitting out the CSV column) is
to maintain the order of items within the CSV columns. for example, StroreID
1051 has Category1CSV contents of "Flour,Yeast,Baking Powder". Those will map
to the columns ItemName, ItemRank, and ItemCategory such that ItemName =
Flour, it's ItemRank = 1, and the ItemCategory = 1. This would be the first
row in Table 2. The second row would be ItemName = Yeast, it's ItemRank = 2,
and the ItemCategory = 1, and so on until you end up with what looks like
Table 2 above. Also, you'll notice that the ItemRank numbering starts with the
contents of the column Category1CSV, then continues to Category2CSV and
finally Category3CSV.
After that lengthy explanation, is it possible to have some SQL statement that
will create Table 2 from Table 1 for me? If so, what would that look like? I'm
planning to use MS SQL Server Express 2012.
OR... as someone suggest to me, it may be best to have some VBA in Excel or
Python script (maybe in conjunction with Notepad++?) to accomplish this, then
just import the final data? I don't care either way, I just can't keep
manually editing the CSV file, as it's very tedious and time consuming.
Thank you!
Answer: I would use a Split function in order to split the additional values.
The Split function I use uses a Numbers (a table with numbers 1 through
1,000,000) in order to facilitate the split process.
Once the Numbers table and Split functions are in place, I would use the CROSS
APPLY function to apply the Split to the CSV columns. the code to split the
CSV column would look like this (this is just a couple test rows based on your
data provided).
DECLARE @Table TABLE (val1 VARCHAR(50), val2 VARCHAR(50), val3 VARCHAR(50), csv1 VARCHAR(100), csv2 VARCHAR(100), csv3 VARCHAR(100))
INSERT INTO @Table
VALUES ('Easton', 'Columbus', 'OH', 'Flour,Yeast,Baking Powder','Milk,Water,Oil','Cinnamon,Sugar')
, ('Crocker Park', 'Westlake', 'OH', 'Baking Powder,Yeast,Flour','Oil,Milk,Water','Rosemary,Cinnamon,Sugar')
SELECT tbl.val1, val2, val3, apl.*
FROM @Table tbl
CROSS APPLY(
SELECT val
FROM dbo.Split(tbl.csv1, ',')
) apl
UNION ALL
SELECT tbl.val1, val2, val3, apl.*
FROM @Table tbl
CROSS APPLY(
SELECT val
FROM dbo.Split(tbl.csv2, ',')
) apl
UNION ALL
SELECT tbl.val1, val2, val3, apl.*
FROM @Table tbl
CROSS APPLY(
SELECT val
FROM dbo.Split(tbl.csv3, ',')
) apl
ORDER BY val1
The output of which will look like this based on the sample date.
Crocker Park Westlake OH Baking Powder
Crocker Park Westlake OH Cinnamon
Crocker Park Westlake OH Flour
Crocker Park Westlake OH Milk
Crocker Park Westlake OH Oil
Crocker Park Westlake OH Rosemary
Crocker Park Westlake OH Sugar
Crocker Park Westlake OH Water
Crocker Park Westlake OH Yeast
Easton Columbus OH Baking Powder
Easton Columbus OH Cinnamon
Easton Columbus OH Flour
Easton Columbus OH Milk
Easton Columbus OH Oil
Easton Columbus OH Sugar
Easton Columbus OH Water
Easton Columbus OH Yeast
Here is the code to create the Numbers table
DECLARE @tbl TABLE (n INT)
INSERT INTO @tbl (n)
VALUES (1),(2),(3),(4),(5),(6),(7),(8),(9),(10)
; WITH Num AS(
SELECT one.n
FROM @tbl one
CROSS JOIN @tbl two
CROSS JOIN @tbl three
CROSS JOIN @tbl four
CROSS JOIN @tbl five
CROSS JOIN @tbl six
)
SELECT ROW_NUMBER() OVER(ORDER BY n) AS n
INTO dbo.Numbers
FROM Num
ALTER TABLE dbo.Numbers
ALTER COLUMN n INT NOT NULL
ALTER TABLE dbo.Numbers
ADD PRIMARY KEY (n)
GO
Lastly, here is the code to create the Split function.
CREATE FUNCTION dbo.Split
(
@List VARCHAR(MAX),
@Delimiter VARCHAR(255)
)
RETURNS TABLE
AS
RETURN
(
SELECT val = SUBSTRING(@List, n, CHARINDEX(@Delimiter, @List + @Delimiter, n) - n)
FROM dbo.Numbers
WHERE n <= CONVERT(INT, LEN(@List))
AND SUBSTRING(@Delimiter + @List, n, LEN(@Delimiter)) = @Delimiter
);
GO
|
Python 3: Finding word which appears the most times without using import or counter or dictionary, only simple tools like .split() and .lower()
Question: I am currently learning Python and trying to solve a free tutorial question.
Here is the question.
A writer is working on their newest poem, Turing and the Machines. They have
hired you to determine the word which appears the most times. You can access
the lines of the poem by calling input() repeatedly, and the last line
contains the three characters ###. All lines consist of words separated by
single spaces; there are no digits or punctuation. Convert all the words to
lower-case, and print the word that occurs the most times (we guarantee there
will not be a tie). For example, if the input is
Here is a line like sparkling wine
Line up fast or be the last
# # #
Then the output should be
line
since it appears twice and no other word appears twice.
..........Below is the closest thing to a solution I can get.
It still lacks , among other things, the facility to allow a user to call
input() repeatedly.
And it only prints out the maximum number of the most used word , not the word
itself that the question wants.
The poem is supplied by the website shell , at
<http://cscircles.cemc.uwaterloo.ca/15b-python-pushups/>
Let's assume the user will input the poem one line at a time.
Please help. Thanks a million.
..........
def poem(P):
P_lower = P.lower()
P_split = P_lower.split()
word_list = []
wordfreq = []
for i in P_split:
word_list.append(i)
for i in P_split:
wordfreq.append(P_split.count(i))
print(max(wordfreq))
poem('Here is a line like line sparkling line wine')
Answer: This doesn't use any of the "restricted" tools but only lower(), split() and
sort() to return the word with the most occurrences.
def main():
done = False
P = ""
while not done:
new_line = input()
if new_line != "###":
P += new_line + " "
else:
done = True
poem_words = P.lower().split()
poem_words.sort()
# Initialize variables
temp = ""
max_count = 0
icount = 1
max_word = ""
# Do the loop
for i in range(len(poem_words)):
if temp == poem_words[i]:
icount += 1
else:
temp = poem_words[i]
icount = 1
if icount > max_count:
max_count = icount
max_word = temp
print(max_word)
return
if __name__ == "__main__":
main()
|
Copy with Different Memory Address - Python
Question: I made a class object I'll call Node.
I want to make a copy of an instance of this object. Let's say the original is
named "root" and the copy is to be named "start"
If I do start = root.
When I make any changes to start, it also changes root. This is because they
share a memory address.
How can I make start = root with different memory address?
I tried messing around with copy/deepcopy after some searching but it tells me
there is no such attribute.
Is there an easy way to do this?
Thanks!
Answer: I've solved this problem using deepcopy from the lib copy. In my case I had
other objects within the object I wanted to duplicate, so I had to use
deepcopy otherwise just copy would have solved the problem. Take a look at the
lib's documentation (<https://docs.python.org/2/library/copy.html>)
Remember:
import copy
start = copy.deepcopy(root)
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Python attribute button error
Question: Hey guys im just trying to create a simple button gui (absolute n00b ) but i
can seem to figure out whats wrong with my code:
``__author__ = 'Isaac'
from Tkinter import *
class Application(Frame):
""" My smart board application"""
def __init__(self, master):
Frame.__init__(self, master)
self.grid()
self.create_widgets()
def create_widgets(self):
#Button1
self.button1 = Button(self, text = "Calandar")
self.button1.grid()
#button2
self.button2 = Button(self)
self.button2.grid()
self.button.configure(text = "Weather")
root = Tk()
root.title("Smartboard")
root.geometry("500x400")
app = Application(root)
root.mainloop()
the error im getting is:
C:\Python27\python.exe "C:/Users/Isaac/Desktop/Useful python/Clanadar/GUIOOP.py"
Traceback (most recent call last):
File "C:/Users/Isaac/Desktop/Useful python/Clanadar/GUIOOP.py", line 25, in <module>
app = Application(root)
File "C:/Users/Isaac/Desktop/Useful python/Clanadar/GUIOOP.py", line 11, in __init__
self.create_widgets()
File "C:/Users/Isaac/Desktop/Useful python/Clanadar/GUIOOP.py", line 20, in create_widgets
self.button.configure(text = "Weather")
AttributeError: Application instance has no attribute 'button'
Process finished with exit code 1
thanks for your help
Answer: Under your "#button2" comment;3 lines below, you used
self.button.configure()
However there is no variable called "button". I think you meant to say:
self.button2.configure()
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Fastest way to pack and unpack binary data into list
Question: I am writing a script which will read 32 bytes of data from over thousands of
files. The 32 bytes consists of 8 pairs of 16-bit integers and I want to
unpack them to Python integers to build a list consisting of average numbers.
I would then like to print out a hex string (packed the same way it was
unpacked) of the list, along with the list object itself, to the user running
the script.
My current code looks like this, and it's slower than I'd like it to be (even
considering the heavy I/O load):
import os
import sys
import struct
import binascii
def list_str(list):
return str(list)
def list_s16be_hex(list):
i = 0
bytes = b""
while i < len(list):
bytes += struct.pack(">h", list[i])
i += 1
return binascii.hexlify(bytes).decode("ascii")
def main():
averages = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
root = os.path.dirname(__file__)
for dirpath, dirnames, filenames in os.walk(root):
for filename in filenames:
with open(os.path.join(dirpath, filename), "rb") as f:
f.seek(0x10)
tmp = f.read(32)
i = 0
while i < 32:
averages[i//2] = (averages[i//2] + struct.unpack(">h", tmp[i:i+2])[0]) // 2
i += 2
print("Updated averages (hex): " + list_s16be_hex(averages))
print("Updated averages (list): " + list_str(averages))
return 0
if __name__=="__main__":
main()
Is there a more efficient way of doing this?
Answer: You can unpack all 16 integers at once, using `struct.unpack(">16h", tmp)`,
which should be significantly faster for the computational part. Otherwise I'd
expect your program runtime to be dominated by the I/O, which you can check by
measuring it's runtime without the average computation. There is not so much
you can do about the I/O.
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