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Subprocess module in Python to cmd.exe
Question: I have some code here trying to open up the `cmd.exe` from Python and input
some lines for the command to use.
Here it is:
PDF= "myPDF"
output= "my output TIF"
def my_subprocess(command,c='C:\here'):
process = subprocess.Popen(command,stdout=subprocess.PIPE,shell=True,cwd=c)
communicate = process.communicate()[0].strip()
my_subprocess('"cmd.exe" && "C:\\here\\myinfamous.bat" && "C:\\my directory and lines telling cmd to do stuff"'+ PDF + " " + output)
When run with the rest of my script, the command prompt does not even open up
and there seems to be no output or errors at all. My thought is that it has
not even run the `cmd.exe` command so none of this code is going in to create
the final output.
Is there something I am not doing properly?
Thank you.
Answer: You need to replace `subprocess.Popen` with `subprocess.call`
Here is a working code on windows 8 that opens a text file using notepad.
First field is the command itself and second field is argument.
You can modify these and test with your files.
import subprocess
subprocess.call(['C:\\Windows\\System32\\Notepad.exe', 'C:\\openThisfile.txt'])
|
Cache Proxy Server Returning 404 with www.google.com
Question: I have a homework assignment which involves implementing a proxy cache server
in Python for web pages. Here is my implementation of it
from socket import *
import sys
def main():
#Create a server socket, bind it to a port and start listening
tcpSerSock = socket(AF_INET, SOCK_STREAM) #Initializing socket
tcpSerSock.bind(("", 8030)) #Binding socket to port
tcpSerSock.listen(5) #Listening for page requests
while True:
#Start receiving data from the client
print 'Ready to serve...'
tcpCliSock, addr = tcpSerSock.accept()
print 'Received a connection from:', addr
message = tcpCliSock.recv(1024)
print message
#Extract the filename from the given message
filename = ""
try:
filename = message.split()[1].partition("/")[2].replace("/", "")
except:
continue
fileExist = False
try: #Check whether the file exists in the cache
f = open(filename, "r")
outputdata = f.readlines()
fileExist = True
#ProxyServer finds a cache hit and generates a response message
tcpCliSock.send("HTTP/1.0 200 OK\r\n")
tcpCliSock.send("Content-Type:text/html\r\n")
for data in outputdata:
tcpCliSock.send(data)
print 'Read from cache'
except IOError: #Error handling for file not found in cache
if fileExist == False:
c = socket(AF_INET, SOCK_STREAM) #Create a socket on the proxyserver
try:
srv = getaddrinfo(filename, 80)
c.connect((filename, 80)) #https://docs.python.org/2/library/socket.html
# Create a temporary file on this socket and ask port 80 for
# the file requested by the client
fileobj = c.makefile('r', 0)
fileobj.write("GET " + "http://" + filename + " HTTP/1.0\r\n")
# Read the response into buffer
buffr = fileobj.readlines()
# Create a new file in the cache for the requested file.
# Also send the response in the buffer to client socket and the
# corresponding file in the cache
tmpFile = open(filename,"wb")
for data in buffr:
tmpFile.write(data)
tcpCliSock.send(data)
except:
print "Illegal request"
else: #File not found
print "404: File Not Found"
tcpCliSock.close() #Close the client and the server sockets
main()
I configured my browsers to use my proxy server like so
[](http://i.stack.imgur.com/o2FjV.jpg)
But my problem when I run it is that no matter what web page I try to access
it returns a 404 error with the initial connection and then a connection reset
error with subsequent connections. I have no idea why so any help would be
greatly appreciated, thanks!
Answer: There are quite a number of issues with your code.
Your URL parser is quite cumbersome. Instead of the line
filename = message.split()[1].partition("/")[2].replace("/", "")
I would use
import re
parsed_url = re.match(r'GET\s+http://(([^/]+)(.*))\sHTTP/1.*$', message)
local_path = parsed_url.group(3)
host_name = parsed_url.group(2)
filename = parsed_url.group(1)
If you catch an exception there, you should probably throw an error because it
is a request your proxy doesn't understand (e.g. a POST).
When you assemble your request to the destination server, you then use
fileobj.write("GET {object} HTTP/1.0\n".format(object=local_path))
fileobj.write("Host: {host}\n\n".format(host=host_name))
You should also include some of the header lines from the original request
because they can make a major difference to the returned content.
Furthermore, you currently cache the entire response with all header lines, so
you should not add your own when serving from cache.
What you have doesn't work, anyway, because there is no guarantee that you
will get a 200 and `text/html` content. You should check the response code and
only cache if you did indeed get a 200.
|
Python header unicode to dict
Question: I have a MySQL database with a python request header saved in one of the
columns and it looks something like this:
{
'_': '/Users/user/.virtualenvs/squadraft/bin/python',
'wsgi.multiprocess': False, 'RUN_MAIN': 'true',
'rvm_version': '1.26.11 (latest)',
'HTTP_ACCEPT_LANGUAGE': 'en-US,en;q=0.8,fr;q=0.6',
'PIP_RESPECT_VIRTUALENV': 'true',
'SERVER_SOFTWARE': 'WSGIServer/0.1 Python/2.7.5',
'rvm_path': '/Users/user/.rvm',
'TERM_PROGRAM_VERSION': '326',
'RUBY_VERSION': 'ruby-2.0.0-p643',
'REQUEST_METHOD': 'POST',
'LOGNAME': 'user',
'USER': 'user',
'HTTP_ORIGIN': 'chrome-extension://fhbjgbiflinjbdggehcddcbncdddomop',
'PATH': '/Users/user/.virtualenvs/squadraft/bin:/Users/user/.rvm/gems/ruby-2.0.0-p643/bin:/Users/user/.rvm/gems/ruby-2.0.0-p643@global/bin:/Users/user/.rvm/rubies/ruby-2.0.0-p643/bin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/usr/local/sbin:/Users/user/.rvm/bin:/Users/user/.rvm/bin',
'QUERY_STRING': '',
'HOME': '/Users/user',
'VIRTUALENVWRAPPER_SCRIPT': '/usr/local/bin/virtualenvwrapper.sh',
'HTTP_CONNECTION': 'keep-alive',
'TERM_PROGRAM': 'Apple_Terminal',
'LANG': 'en_US.UTF-8',
'TERM': 'xterm-256color',
'SHELL': '/bin/bash',
'TZ': 'UTC',
'SERVER_NAME': '1.0.0.127.in-addr.arpa',
'VERSIONER_PYTHON_VERSION': '2.7',
'SHLVL': '1',
'_system_name': 'OSX',
'wsgi.url_scheme': 'http',
'VIRTUALENVWRAPPER_VIRTUALENV_ARGS': '--no-site-packages',
'SERVER_PORT': '8000',
'CONTENT_LENGTH': '38414',
'SERVER_PROTOCOL': 'HTTP/1.1',
'_system_arch': 'x86_64',
'GEM_PATH': '/Users/user/.rvm/gems/ruby-2.0.0-p643:/Users/user/.rvm/gems/ruby-2.0.0-p643@global',
'rvm_bin_path': '/Users/user/.rvm/bin',
'WORKON_HOME': '/Users/user/.virtualenvs',
'TERM_SESSION_ID': '8CFC3FA5-6F56-49B7-AFAB-A807AFFA1D83',
'VERSIONER_PYTHON_PREFER_32_BIT': 'no',
'CONTENT_TYPE': 'application/xml',
'rvm_prefix': '/Users/user',
'HTTP_POSTMAN_TOKEN': 'c084799e-820d-7f70-4b7e-7597f1abab6f',
'Apple_PubSub_Socket_Render': '/tmp/launch-g9J1iQ/Render',
'SSH_AUTH_SOCK': '/tmp/launch-JlZPBH/Listeners',
'VIRTUAL_ENV': '/Users/user/.virtualenvs/squadraft',
'LC_CTYPE': 'UTF-8',
'IRBRC': '/Users/user/.rvm/rubies/ruby-2.0.0-p643/.irbrc',
'MY_RUBY_HOME': '/Users/user/.rvm/rubies/ruby-2.0.0-p643',
'HTTP_CACHE_CONTROL': 'no-cache',
'VIRTUALENVWRAPPER_WORKON_CD': '1',
'PS1': '(squadraft) \h:\W \u\$ ',
'SCRIPT_NAME': u'',
'wsgi.multithread': True, 'LC_ALL': 'en_US.UTF-8',
'_system_type': 'Darwin',
'TMPDIR': '/var/folders/5c/vhcdkw8n6xz2n_ywlkvt2q_r0000gn/T/',
'HTTP_ACCEPT': '*/*',
'VIRTUALENVWRAPPER_PROJECT_FILENAME': '.project',
'wsgi.version': (1, 0), 'VIRTUALENVWRAPPER_HOOK_DIR': '/Users/user/.virtualenvs',
'GATEWAY_INTERFACE': 'CGI/1.1',
'wsgi.run_once': False, 'REMOTE_HOST': '',
'OLDPWD': '/Users/user/Development/rotas',
'REMOTE_ADDR': '127.0.0.1',
'HTTP_USER_AGENT': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_9_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/48.0.2564.116 Safari/537.36',
'wsgi.input': <socket._fileobject object at 0x112519cd0>,
'wsgi.errors': <open file '<stderr>', mode 'w' at 0x10f4891e0>,
'HTTP_ACCEPT_ENCODING': 'gzip, deflate',
'__CF_USER_TEXT_ENCODING': '0x1F5:0:0',
'PWD': '/Users/user/Development/squadraft',
'PIP_VIRTUALENV_BASE': '/Users/user/.virtualenvs',
'DJANGO_SETTINGS_MODULE': 'fantasysport.settings.local',
'_system_version': '10.9',
'HTTP_HOST': '127.0.0.1:8000',
'wsgi.file_wrapper': <class wsgiref.util.FileWrapper at 0x110994258>,
'__CHECKFIX1436934': '1',
'GEM_HOME': '/Users/user/.rvm/gems/ruby-2.0.0-p643',
'PATH_INFO': u'/client/collect-data/'
}
Note accessing it through my model query I get it as Unicode. I would like to
convert this into a dictionary so that I can access the underlying properties.
Here are some of the things I have tried so far.
import json
json.loads(header_data)
# This fails with a 'ValueError: Expecting property name
# enclosed in double quotes: line 1 column 2 (char 1)'
# Also
import ast
ast.literal_eval(header_data)
# The above fails with a 'File "<unknown>", line 1' error
More information:
print(type(header_data))
<type 'unicode'>
print(header_data)
{'_': '/Users/user/.virtualenvs/squadraft/bin/python', 'wsgi.multiprocess': False, 'RUN_MAIN': 'true', 'rvm_version': '1.26.11 (latest)', 'HTTP_ACCEPT_LANGUAGE': 'en-US,en;q=0.8,fr;q=0.6', 'PIP_RESPECT_VIRTUALENV': 'true', 'SERVER_SOFTWARE': 'WSGIServer/0.1 Python/2.7.5', 'rvm_path': '/Users/user/.rvm', 'TERM_PROGRAM_VERSION': '326', 'RUBY_VERSION': 'ruby-2.0.0-p643', 'REQUEST_METHOD': 'POST', 'LOGNAME': 'user', 'USER': 'user', 'HTTP_ORIGIN': 'chrome-extension://fhbjgbiflinjbdggehcddcbncdddomop', 'PATH': '/Users/user/.virtualenvs/squadraft/bin:/Users/user/.rvm/gems/ruby-2.0.0-p643/bin:/Users/user/.rvm/gems/ruby-2.0.0-p643@global/bin:/Users/user/.rvm/rubies/ruby-2.0.0-p643/bin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/usr/local/sbin:/Users/user/.rvm/bin:/Users/user/.rvm/bin', 'QUERY_STRING': '', 'HOME': '/Users/user', 'VIRTUALENVWRAPPER_SCRIPT': '/usr/local/bin/virtualenvwrapper.sh', 'HTTP_CONNECTION': 'keep-alive', 'TERM_PROGRAM': 'Apple_Terminal', 'LANG': 'en_US.UTF-8', 'TERM': 'xterm-256color', 'SHELL': '/bin/bash', 'TZ': 'UTC', 'SERVER_NAME': '1.0.0.127.in-addr.arpa', 'VERSIONER_PYTHON_VERSION': '2.7', 'SHLVL': '1', '_system_name': 'OSX', 'wsgi.url_scheme': 'http', 'VIRTUALENVWRAPPER_VIRTUALENV_ARGS': '--no-site-packages', 'SERVER_PORT': '8000', 'CONTENT_LENGTH': '38414', 'SERVER_PROTOCOL': 'HTTP/1.1', '_system_arch': 'x86_64', 'GEM_PATH': '/Users/user/.rvm/gems/ruby-2.0.0-p643:/Users/user/.rvm/gems/ruby-2.0.0-p643@global', 'rvm_bin_path': '/Users/user/.rvm/bin', 'WORKON_HOME': '/Users/user/.virtualenvs', 'TERM_SESSION_ID': '8CFC3FA5-6F56-49B7-AFAB-A807AFFA1D83', 'VERSIONER_PYTHON_PREFER_32_BIT': 'no', 'CONTENT_TYPE': 'application/xml', 'rvm_prefix': '/Users/user', 'HTTP_POSTMAN_TOKEN': 'c084799e-820d-7f70-4b7e-7597f1abab6f', 'Apple_PubSub_Socket_Render': '/tmp/launch-g9J1iQ/Render', 'SSH_AUTH_SOCK': '/tmp/launch-JlZPBH/Listeners', 'VIRTUAL_ENV': '/Users/user/.virtualenvs/squadraft', 'LC_CTYPE': 'UTF-8', 'IRBRC': '/Users/user/.rvm/rubies/ruby-2.0.0-p643/.irbrc', 'MY_RUBY_HOME': '/Users/user/.rvm/rubies/ruby-2.0.0-p643', 'HTTP_CACHE_CONTROL': 'no-cache', 'VIRTUALENVWRAPPER_WORKON_CD': '1', 'PS1': '(squadraft) \h:\W \u\$ ', 'SCRIPT_NAME': u'', 'wsgi.multithread': True, 'LC_ALL': 'en_US.UTF-8', '_system_type': 'Darwin', 'TMPDIR': '/var/folders/5c/vhcdkw8n6xz2n_ywlkvt2q_r0000gn/T/', 'HTTP_ACCEPT': '*/*', 'VIRTUALENVWRAPPER_PROJECT_FILENAME': '.project', 'wsgi.version': (1, 0), 'VIRTUALENVWRAPPER_HOOK_DIR': '/Users/user/.virtualenvs', 'GATEWAY_INTERFACE': 'CGI/1.1', 'wsgi.run_once': False, 'REMOTE_HOST': '', 'OLDPWD': '/Users/user/Development/rotas', 'REMOTE_ADDR': '127.0.0.1', 'HTTP_USER_AGENT': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_9_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/48.0.2564.116 Safari/537.36', 'wsgi.input': <socket._fileobject object at 0x112519cd0>, 'wsgi.errors': <open file '<stderr>', mode 'w' at 0x10f4891e0>, 'HTTP_ACCEPT_ENCODING': 'gzip, deflate', '__CF_USER_TEXT_ENCODING': '0x1F5:0:0', 'PWD': '/Users/user/Development/squadraft', 'PIP_VIRTUALENV_BASE': '/Users/user/.virtualenvs', 'DJANGO_SETTINGS_MODULE': 'fantasysport.settings.local', '_system_version': '10.9', 'HTTP_HOST': '127.0.0.1:8000', 'wsgi.file_wrapper': <class wsgiref.util.FileWrapper at 0x110994258>, '__CHECKFIX1436934': '1', 'GEM_HOME': '/Users/user/.rvm/gems/ruby-2.0.0-p643', 'PATH_INFO': u'/opta/collect-data/'}
Answer: As had already been pointed out in a deleted answer, your problem are the
entries
'wsgi.input': <socket._fileobject object at 0x112519cd0>
'wsgi.errors': <open file '<stderr>', mode 'w' at 0x10f4891e0>
'wsgi.file_wrapper': <class wsgiref.util.FileWrapper at 0x110994258>
Remove these and
ast.literal_eval(header_data)
should work.
|
Background Timer in PyQt Python Applicatiion
Question: I am Building an application in python using PyQt4. I want to add a background
timer to my application so that when the timer runs out, the text editor in my
application stops receiving input and freezes up. I have tried the following
method so far:
def main():
app = QtGui.QApplication(sys.argv)
main = Main()
main.show()
start = time.time()
#this loop is for the time interval within which the text area of
#the editor will accept inputs.
while time.time() - start < 120:
pass
#this will set the text area to a read only state after and will not
#any more inputs.
main.text.setReadOnly(True)
sys.exit(app.exec_())
But whenever I run this the application stops responding. I have also tried
running the timer through a thread but in that case also the application stops
responding.
How can I implement this functionality?
P.S. - I am a Beginner in PyQt.
class Main(QtGui.QMainWindow):
def __init__(self,parent = None):
QtGui.QMainWindow.__init__(self,parent)
self.init_ui()
def init_ui(self):
self.text = QtGui.QTextEdit(self)
self.setCentralWidget(self.text)
self.statusbar = self.statusBar()
self.setGeometry(100,100,1080,720)
self.setWindowTitle("Text Editor")
This is the watered down version of the main class code. Hope this helps.
Answer: Your application is not responding because you are blocking the event handler.
It is processed by `app.exec_()`. This call is only checking for events and
handling these in a infinite loop.
Use QTimer with **signal** and **slot**.
[Signals and Slots
(wikipedia)](https://en.wikipedia.org/wiki/Signals_and_slots)
For using signals and slots in pyqt see
[this](http://pyqt.sourceforge.net/Docs/PyQt4/new_style_signals_slots.html).
The timer is initialized with a duration and a signal-slot connection. After
`app.exec_()` is called, it will wait for the `input_timer` signal `timeout`.
If this is raised, the event loop will call lambda function, that disables the
textbox, because it is connected to the signal.
def main():
app = QtGui.QApplication(sys.argv)
main = Main()
main.show()
input_timer = QTimer(self)
input_timer.timeout.connect(lambda : main.text.setReadOnly(True))
input_timer.setSingleShot(True)
input_timer.start(2000)
sys.exit(app.exec_())
This will disable the textbox after 2000 milliseconds. Adjust as you need. I
would move the timer and behaviour to `Main` class.
import sys
from PyQt4 import QtCore, QtGui
class Main(QtGui.QMainWindow):
def __init__(self,parent = None):
QtGui.QMainWindow.__init__(self,parent)
self.init_ui()
self.disable_edit_text_timer = QtCore.QTimer(self)
self.disable_edit_text_timer.timeout.connect(self.disable_edit_text)
self.disable_edit_text_timer.setSingleShot(True)
self.disable_edit_text_timer.start(2000)
def init_ui(self):
self.text = QtGui.QTextEdit(self)
self.setCentralWidget(self.text)
self.statusbar = self.statusBar()
self.setGeometry(100,100,1080,720)
self.setWindowTitle("Text Editor")
def disable_edit_text(self):
self.text.setReadOnly(True)
def main():
app = QtGui.QApplication(sys.argv)
main = Main()
main.show()
sys.exit(app.exec_())
if __name__ == "__main__":
main()
|
pyGame image scale does not work as expected
Question: I am new into Python and pyGame and i have a problem with scaling an image. I
want to zoom an image in pygame. The pygame documentation claims that
> pygame.transform.scale()
should scale to a new resolution. But in my example below it does not work -
it crops the image instead of resizing it!? What am i doing wrong?
#!/usr/bin/env python3
# coding: utf-8
import pygame
from pygame.locals import *
# Define some colors
BLACK = (0, 0, 0)
pygame.init()
# Set the width and height of the screen [width, height]
screen = pygame.display.set_mode((1920, 1080))
pic = pygame.image.load('test.jpg').convert()
pic_position_and_size = pic.get_rect()
# Loop until the user clicks the close button.
done = False
# Clear event queue
pygame.event.clear()
# -------- Main Program Loop -----------
while not done:
for event in pygame.event.get():
if event.type == QUIT:
done = True
elif event.type == KEYDOWN:
if event.key == K_ESCAPE:
done = True
# background in black
screen.fill(BLACK)
# Copy image to screen:
screen.blit(pic, pic_position_and_size)
# Update the screen with what we've drawn.
pygame.display.flip()
pygame.display.update()
pygame.time.delay(10) # stop the program for 1/100 second
# decreases size by 1 pixel in x and y axis
pic_position_and_size = pic_position_and_size.inflate(-1, -1)
# scales the image
pic = pygame.transform.scale(pic, pic_position_and_size.size)
# Close the window and quit.
pygame.quit()
Answer: `pygame.transform.scale()` does not work very well for your case. If you
shrink a `Surface` by such a small amount, the algorithm just crops the last
column and row of pixels. If you now repeat this process over and over again
with the same `Surface`, you get the strange behaviour you see.
A better approach would be to keep a copy of your original `Surface` around,
and use that for creating the scaled image. Also, using `smoothscale` instead
of `scale` may also lead to a better effect; it's up to you if you want to use
it.
Here's a "fixed" version of your code:
#!/usr/bin/env python3
# coding: utf-8
import pygame
from pygame.locals import *
# Define some colors
BLACK = (0, 0, 0)
pygame.init()
# Set the width and height of the screen [width, height]
screen = pygame.display.set_mode((1920, 1080))
org_pic = pygame.image.load('test.jpg').convert()
pic_position_and_size = org_pic.get_rect()
pic = pygame.transform.scale(org_pic, pic_position_and_size.size)
# Loop until the user clicks the close button.
done = False
# Clear event queue
pygame.event.clear()
# -------- Main Program Loop -----------
while not done:
for event in pygame.event.get():
if event.type == QUIT:
done = True
elif event.type == KEYDOWN:
if event.key == K_ESCAPE:
done = True
# background in black
screen.fill(BLACK)
# Copy image to screen:
screen.blit(pic, (0,0))
# Update the screen with what we've drawn.
pygame.display.flip()
pygame.display.update()
pygame.time.delay(10) # stop the program for 1/100 second
# decreases size by 1 pixel in x and y axis
pic_position_and_size = pic_position_and_size.inflate(-1, -1)
# scales the image
pic = pygame.transform.smoothscale(org_pic, pic_position_and_size.size)
# Close the window and quit.
pygame.quit()
|
Distributed Programming on Google Cloud Engine using Python (mpi4py)
Question: I want to do distributed programming with python using the mpi4py package. For
testing reasons, I set up a 5-node cluster via Google container engine, and
changed my code accordingly. But now, what are my next steps? How do I get my
code running and working on all 5 VMs?
I tried to just ssh-connect into one VM from my cluster and run the code, but
it was obvious that the code was not getting distributed, but instead stayed
on the same machine :( [see example below]
.
# Code:
from mpi4py import MPI
size = MPI.COMM_WORLD.Get_size()
rank = MPI.COMM_WORLD.Get_rank()
name = MPI.Get_processor_name()
print("Hello, World! I am process/rank {} of {} on {}.\n".format(rank, size,name))
.
# Output:
> **mpiexec -n 5 python 5_test.py**
>
>> Hello, World! I am process/rank 0 of 5 on gke-cluster-1-000000cd-node-mgff.
>>
>> Hello, World! I am process/rank 1 of 5 on gke-cluster-1-000000cd-node-mgff.
>>
>> Hello, World! I am process/rank 2 of 5 on gke-cluster-1-000000cd-node-mgff.
>>
>> Hello, World! I am process/rank 3 of 5 on gke-cluster-1-000000cd-node-mgff.
>>
>> Hello, World! I am process/rank 4 of 5 on gke-cluster-1-000000cd-node-mgff.
Answer: So, I figured out what I got wrong, and I think I should post the answer for
someone who might has a similar question.
Turns out, I should have read the documentation of mpi4py better :D
The command `mpirun -np 5 python 5_test.py` is for running the program an a
single, multi-core host on different processes.
However, I wanted to distribute the task across various host. Therefore I
needed the command `mpirun --hostfile <hostfile> python 5_test.py`. And
`<hostfile>` must be a file looking like this:
-- hostfile --
host1 slots=4
host2 slots=4
host3 slots=4
'--------------
.
Useful Link: <https://github.com/jbornschein/mpi4py-examples>
|
UnicodeDecodeError from sound file
Question: I'm trying to make a speech recogniser in Python using Google speech API. I've
been using and adapting the code from
[here](http://stackoverflow.com/a/19828908/4961615) (converted to Python3).
I'm using an audio file on my computer that's been converted from mp3 to flac
16000 Hz (as specified in the original code) using an online converter. When
running the code I get this error:
$ python3 speech_api.py 02-29-2016_00-12_msg1.flac
Traceback (most recent call last):
File "speech_api.py", line 12, in <module>
data = f.read()
File "/usr/lib/python3.4/codecs.py", line 319, in decode
(result, consumed) = self._buffer_decode(data, self.errors, final)
UnicodeDecodeError: 'utf-8' codec can't decode byte 0x80 in position 9: invalid start byte
This is my code. (I'm sure there are also still things that don't work in
Python3, as I've been trying to adapt it and am new to `urllib`...)
#!/usr/bin/python
import sys
from urllib.request import urlopen
import json
try:
filename = sys.argv[1]
except IndexError:
print('Usage: transcribe.py <file>')
sys.exit(1)
with open(filename) as f:
data = f.read()
req = urllib.request('https://www.google.com/intl/en/chrome/demos/speech.html', data=data, headers={'Content-type': 'audio/x-flac; rate=16000'})
try:
ret = urllib.urlopen(req)
except urllib.URLError:
print("Error Transcribing Voicemail")
sys.exit(1)
resp = ret.read()
text = json.loads(resp)['hypotheses'][0]['utterance']
print(text)
Any ideas what I could do?
Answer: You need to open the file in _binary mode_ :
open(filename, 'wb')
Note the `'b'`, or the file will be treated as text and decoded to Unicode.
|
import numpy on python 3.5 on mac osx
Question: I tried to follow your advices about typing in `macport` :
cd /opt/local/bin
sudo ./port install py35-numpy
and apparently it worked, but Python still doesn't find any module named
`'numpy'`...
Thanks for help
Answer: If you're interested in painlessly using Python with NumPy on Linux, Mac, or
Windows, I'd highly suggest using the
[miniconda](http://conda.pydata.org/miniconda.html) distribution. Once it's
installed, just open a terminal and run
$ conda install python=3.5 numpy
and you'll be ready to go. It also makes the rest of the scientific Python
ecosystem similarly easy to install.
|
django redirect no reverse match error
Question: Here is my main project timecapture/urls.py content:
from django.conf.urls import url,include
from django.contrib import admin
from django.core.urlresolvers import reverse_lazy
from . import views
urlpatterns = [
url(r'^admin/', admin.site.urls),
url(r'^$',views.index,name='index'),
url(r'^login/$',views.auth_login,name='auth_login'),
url(r'^logout/$',views.auth_logout,name='auth_logout'),
url(r'^timesheet/',include('timesheet.urls'),name='timesheet')
]
And here is an app inside main project timesheet/urls.py:
from django.conf.urls import url,include
from django.contrib import admin
from django.http import HttpResponse
from . import views
urlpatterns = [
url(r'^$',views.index),
]
I am unable to redirect to 'timesheet' url. I am using the following command:
return redirect('timesheet')
But this is working:
return redirect('/timesheet/')
Exact error is `enter code here
django.core.urlresolvers.NoReverseMatch: Reverse for 'timesheet' with arguments '()' and keyword arguments '{}' not found. 0 pattern(s) tried: []
Btw I am using latest django 1.9.2 with python 3.4
Answer: You don't have a URL named "timesheet". You've got an include with that name,
but not the views.
Remove `name='timesheet'` from the include in the main urls.py, and add it
instead to the index url in timesheet/urls.py.
|
Python Numpy Poisson Distribution
Question: So basically I am generating a gaussian, for the sake of completeness, that's
my implementation:
from numpy import *
x=linspace(0,1,1000)
y=exp(-(x-0.5)**2/(2.0*(0.1/(2*sqrt(2*log(2))))**2))
with peak at `0.5` and `fwhm=0.1`. So far so not interesting. In the next step
I calculate the poisson distribution of my set of data using `numpys
random.poisson implementation`
poi = random.poisson(lam=y)
So I'm having two major problems.
1. A specialty of poisson is that the variance equals the exp. value, comparing the output of mean() and var() does confuse me as the outputs are not equal.
2. When plotting this, the poisson dist. takes up integer values _only_ and the max. value is around 7, sometimes 6, whilst my old function y has its max. at 1. Afai understand, the poisson-function should give me sort of a 'fit' of my actual function y. How come the max. values are not equal? Sorry for my mathematical incorrectness, actually I'm doing this to emulate poisson-distributed noise but I guess you understand 'fit' in this context.
Thanks in advance.
EDIT: 3. question: What's the 'size' variable used for in this context? I've
seen different types of usage but in the end they did not give me different
results but failing when choosing it wrong...
EDIT2: OK, from the answer I got I think that I was not clear enough (although
it already helped me correct some other stupid errors I did, thanks for
that!). What I want to do is apply poisson (white) noise to the function y. As
described by MSeifert in the post below, I now use the expectation value as
lam. But this only gives me the noise. I guess I have some understanding
problems on the level of how th{is,e} noise is applied (and maybe it's more
physics related?!).
Answer: First of all, I'll write this answer assuming you `import numpy as np` because
it clearly distinguishes `numpy` functions from the builtins or those of the
`math` and `random` package of python.
I think it is not necessary to answer your specified questions because your
basic assumption is wrong:
Yes, the poisson-statistics has a mean that equals the variance but that
assumes you use a **constant** `lam`. But you don't. You input the y-values of
your gaussian, so you cannot expect them to be constant (they are by your
definition gaussian!).
Use `np.random.poisson(lam=0.5)` to get one random value from a poisson
distribution. But be careful since this the poisson distribution is not even
approximatly identical to you gaussian distribution because you are in the
"low-mean" interval where both of these are significantly different, see for
example the [Wikipedia article about Poisson
distribution](https://en.wikipedia.org/wiki/Poisson_distribution).
Also you are creating random numbers, so you shouldn't really plot them but
plot a `np.histogram` of them. Since statistical distributions are all about
probabilitiy density functions (see [Probability density
function](https://en.wikipedia.org/wiki/Probability_density_function)).
Before, I already mentioned that you create a poisson distribution with a
constant `lam` so now it is time to talk about the `size`: You create random
numbers, so to approximate the real poisson distribution you need to draw a
lot of random numbers. There the size comes in: `np.random.poisson(lam=0.5,
size=10000)` for example creates an array of 10000 elements each drawn from a
poissonian probability density function for a mean value of `0.5`.
And if you haven't read it in the Wikipedia article mentioned before the
poisson distribution gives by definition only unsigned (>= 0) integer as
result.
So I guess what you wanted to do is create a gaussian and poisson distribution
containing 1000 values:
gaussian = np.random.normal(0.5, 2*np.sqrt(2*np.log(2)), 1000)
poisson = np.random.poisson(0.5, 1000)
and then to plot it, plot the histograms:
import matplotlib.pyplot as plt
plt.hist(gaussian)
plt.hist(poisson)
plt.show()
or use the
[`np.histogram`](http://docs.scipy.org/doc/numpy-1.10.1/reference/generated/numpy.histogram.html)
instead.
To get statistics from your random samples you can still use `np.var` and
`np.mean` on the gaussian and poisson samples. And this time (at least on my
sample run) they give good results:
print(np.mean(gaussian))
0.653517935138
print(np.var(gaussian))
5.4848398775
print(np.mean(poisson))
0.477
print(np.var(poisson))
0.463471
Notice how the gaussian values are almost exactly what we defined as
parameters. On the other hand poisson mean and var are almost equal. You can
increase the precision of the mean and var by increasing the `size` above.
# Why the poisson distribution doesn't approximate your original signal
Your original signal contains only values between 0 and 1, so the poisson
distribution only allows positive integer and the standard deviation is linked
to the mean value. So far from the mean of the gaussian your signal is
approximatly 0, so the poisson distribution will almost always draw 0. Where
the gaussian has it's maximum the value is 1. The poisson distribution for 1
looks like this (left is the signal + poisson and on the right the poisson
distribution around a value of 1)
[](http://i.stack.imgur.com/hDxf4.png)
so you'll get a lot of 0 and 1 and some 2 in that region. But also there is
some probability that you draw values up to 7. This is exactly the
antisymmetry that I mentioned. If you change the amplitude of your gaussian
(multiply it by 1000 for example) the "fit" is much better since the poisson
distribution is almost symmetric there:
[](http://i.stack.imgur.com/LLSza.png)
|
WSGI import app from python package yields 500
Question: I want to deploy my python app on apache so I made a hello world app
(contained in one python file) and imported the app object from there and it
worked. This was just to test out things.
Then I move my app file there and tried the same with it. I try to import the
app object( now from a python package), nothing blows up, however when I visit
the server I get a 500 error code. Note: the application works just fine if I
run it with python. It is not broken.
File structure:
app.wsgi main(this is the python package) hello.py(this is the simple app)
In app.wsgi I have this:
import sys
sys.path.append('/var/www/html')
from hello import app as application
and that works, but when I change it to :
import sys
sys.path.append('/var/www/html')
from main import app as application
it gives me a 500.
Any ideas as to why is this happening?
Answer: apparently I had to call run in my __init__.py file.
If anyone finds this helpful keep it otherwise take it out.
|
Send email through smtp in superlance using crashmail
Question: I'm trying to set up the email sending when a process changes state in
[supervisord](http://supervisord.org/) by using
[crashmail](https://superlance.readthedocs.org/en/latest/crashmail.html).
Having no luck with the default `sendmail` program which requires quite a lot
of setup, I decided to go with a small script in Python that sends email using
SMTP.
This worked very well (I received indeed an email saying that the process
state changes) for the first state change but stop working afterward. I have
tried to change different options in `supervisord` such as `buffer_size` or
`autorestart` but it has no effect.
Here is the script I use to trigger the `supervisord` state changes:
import time
from datetime import datetime
if __name__ == '__main__':
print(">>>>> STARTING ...", flush=True)
while True:
print("sleep now:", datetime.utcnow(), flush=True)
time.sleep(30)
raise Exception("meo meo")
This is the script that sends email through Gmail. This one will send the
`stdin`.
#!/usr/bin/env python
import smtplib
def get_server():
smtpserver = smtplib.SMTP('smtp.gmail.com:587')
smtpserver.ehlo()
smtpserver.starttls()
smtpserver.login("[email protected]", "password")
return smtpserver
if __name__ == '__main__':
import sys
data = sys.stdin.read()
s = get_server()
s.sendmail('[email protected]', ['[email protected]'], data)
s.quit()
Here is my `supervisord.conf`
[eventlistener:crashmail]
command=crashmail -a -m [email protected] -s /home/ubuntu/mysendmail.py
events=PROCESS_STATE
buffer_size=102400
autorestart=true
Does anyone have any idea why? Thanks!
Answer: I moved the `eventlistener` section to a separate file in
`/etc/supervisor/conf.d` (instead of putting at the end of `supervisord.conf`)
and now everything is working as expected ...
|
Django Shell image upload _io.BufferedReader no attribute size
Question: My problem is that when I try to save image to my model using Django shell I
get this error that I can't find solution anywere.
models.py
class AdImage(models.Model):
ad = models.ForeignKey(Ad)
full_photo = models.ImageField(upload_to='uploads/', blank=True)
I import models create AdImage instance add 'ad' and try to
imagead.full_photo.save("NowHiring.jpg",open("C:\\NowHiring.jpg", "rb"))
but i get an error
Traceback (most recent call last):
File "<console>", line 1, in <module>
File "C:\Users\hp\Envs\platform\lib\site-packages\django\db\models\fields\file
s.py", line 106, in save
self._size = content.size
AttributeError: '_io.BufferedReader' object has no attribute 'size'
Using: **Python 3.5, Django 1.9**
What could I do ?
Answer: The `FieldFile.save` method needs to be called with an instance of
`django.core.files.File`, rather than a built-in python file handle. Change
the save invocation to:
from django.core.files import File
imagead.full_photo.save("NowHiring.jpg", File(open("C:\\NowHiring.jpg", "rb")))
Django docs reference for
[`FieldFile.save`](https://docs.djangoproject.com/en/1.9/ref/models/fields/#django.db.models.fields.files.FieldFile.save).
|
Python Parsing XML with a complex hierarchy - Nuke9.0v8
Question: I am working with NukeX9.0v8, Adobe Premiere Pro CC 2015 and nukes internal
python interrupter.
# Result: 2.7.3 (default, Jul 24 2013, 15:50:23)
[GCC 4.2.1 (Apple Inc. build 5666) (dot 3)]
I am a vfx artist and I'm trying to wrap my brain around the best method to
parse xml files in order to: create a folder structure, batch create .nk comp
files and plug in the data within specific parts as I make my .nk comps. I
have a bit of a grasp of how to do each of these things in isolation, but
plugging it all together, and trying to find tutorials on such complex parse
as ground me to a halt.
I know the scope of this is big but any small pieces of advice are
appreciated.
Right now I have a nuke comp that has a node tree that takes in camera inputs
and stitches them into a latlong image for 360 video, I am going to wrap that
up into a gizmo for each different kind of rig configuration. This just
simplifies the .nk files that are created and I can expose the parts of that
gizmo I can feed data into.
Every day we receive a ton of footage from a shoot and we have to make a new
.nk comp for each shot and set it to render right away. What I want to do is
have the guys on set create a premiere project and organize the files based on
this folder structure. That premiere project will be exported as an .xml file.
The design of the structure in premiere.
* Day_01 (the day of the shoot)
* -^-R001 (Roll number for the shots. R referring to camera type)
* \--^-R001_C001 (The name of the shot)
* \---^-Acamera clip (path to file name, video in point as frame#)
* \---^-Bcamera clip (path to file name, video in point as frame#)
* \---^-Ccamera clip (path to file name, video in point as frame#)
Right now in my script panel inside Nuke I can enter the information of where
is the xml for the day what day to look for. Then it is suppose to look into
each folder name for the roll, and using the first letter (R for RED camera)
and looks inside for the clip folder. It then uses the pathurl directory for
the camera files on the drive and also can take it data like the in and out
points if present in the xml. I also have points to enter for the template
version if I update a stitch process. That will tell the nuke comp which gizmo
to use.
Here is my panel in Nuke.
def sesquixmlparse():
'''
This imports the xml file from premiere. It looks for the bin that it is working for today and starts looking in what is inside the bins
It then sees the bins inside and uses them to create nuke scripts with these as inputs
It asks what template version to use for the rig. things change or maybe even get better
'''
# Lets build the Nuke Panel that tells us our inputs
p = nuke.Panel("Sesqui XML Parse for Dailies")
xml_file = 'Daily XML'
daynumber = 'Day_##'
nk_output_dir = 'Directory to build VFX folder structure'
dnx_render_dir = 'Directory for write nodes'
r_template_vr = 'VER1'
g_template_vr = 'VER1'
c_template_vr = 'VER1'
p.addFilenameSearch("Daily XML", xml_file)
p.addSingleLineInput("Bin to process", daynumber)
p.addFilenameSearch("Directory to build VFX folder structure", nk_output_dir)
p.addFilenameSearch("Directory to render from write nodes", dnx_render_dir)
p.addSingleLineInput("3 Red stmap version", r_template_vr)
p.addSingleLineInput("6 Gopro stmap verison", g_template_vr)
p.addSingleLineInput("5 Canon stmap verison", c_template_vr)
p.setWidth(600)
print "Panel created"
if not p.show():
return
# Assign var from nuke panel user-entered data
xml_file = p.value("Daily XML")
daynumber = p.value("Bin to process")
nk_output_dir = p.value("Directory to build VFX folder structure")
dnx_render_dir = p.value("Directory to render from write nodes")
r_template_vr = p.value("3 Red stmap version")
g_template_vr = p.value("6 Gopro stmap verison")
c_template_vr = p.value("5 Canon stmap verison")
print "var's assigned from panel"
# Create paths for render directory if it does not exist
if not os.path.isdir(dnx_render_dir):
os.mkdir(dnx_render_dir)
print dnx_render_dir + " directory created"
if not os.path.isdir(nk_output_dir):
os.mkdir(nk_output_dir)
print nk_output_dir + " directory created"
I am at a loss on how to best read the xml file. All the tutorials I have seen
on both `DOM` and `elementtree` are very basic and deal with direct code to
read known XML tags and break data down to a simple `str` output.
I need to enter variables, which then constrain the parsing to a specific part
of the tree, and go into an unknown hierarchy setup and seeing what is inside,
and then make decisions on what to do with what it finds.
Here is a sample of my test XML file. The eventual plan is to have other
different roll types that reference different camera types but for now I'm
just working with 3 camera red rigs.
# It's a very big file so here is a pastebin: <http://pastebin.com/vLaRA0X8>
Basically I am wanting to constrain the script to looking within my variable
`<bin><name>'daynumber'</name>~~~~</bin>.` In this case looking in the
`Day_00` bin. If there is anything else in the root hierarchy I want to ignore
it as sequences, unused clips and other data can get very very huge. I then
want to create the directory of `daynumber` in the `nk_output_dir` &
`dnx_render_dir` so that everything for this shoot day is contained in that
folder.
A annoying part of the XML file is the name of a bin is a child to the `<bin>`
itself, so once a bin name is found, any `<children>` of that bin would be the
same level of the tree as the `<name>`. I can't find sample code of locating a
tag and then looking working with the tags that are in the same branch instead
of it's children.
Now that it has found the bin for the day I want it to start to look for all
the bins in `<children></children>`. Example being
`<bin><name>R001</name>~~~</bin>` and create directories inside the Day_00
folder I made in `nk_output_dir` & `dnx_render_dir` for each bin it finds in
this part of the structure. Every time the camera reloads that will roll up to
R002, R003, etc etc. Also different camera types like Gopros will create G001,
G002, G003.
Then I want to look for in the `<children>` of the above bins and find all the
bins inside like `<bin><name>R001_C001</name>~~~</bin>` and create folders in
the `nk_output_dir\`daynumber`\~whatever bin this is contained~\~name of this
bin~\`. Which is user created of the roll number and clip number. (R001_C001,
R001_C002, etc etc) This will be the new clip name, the name of the .nk comp
that will be generated and the file name of the render on the write node.
The goal here is to recreate the bin folder structure in the directory I've
choosen for `nk_output_dir`.
The `dnx_render_dir` that is for being plugged into the write nodes of my nuke
scripts later to where the files should be rendered to. It's separate because
I'd have a different RAID drive that it will go to that will change as they
fill up. The renders just need to be put in a directory for the
`daynumber\~rollnumber~` but doesn't need to be constrained into a folder for
the clipname.
Here is where I am really lost. Now, because I have to account for user error,
I can't be entirely sure how deep in the tree I need to be going. I know I
want the `<pathurl>~</pathurl>` which I can plug into the .nk (nuke) scripts I
make. With red camera files they can either be the directly here .R3D or the
folder structure which can been 2-3 bins deep. I know that I can't 100% rely
on the guys on set to be consistent on how they make this bin.
All I can trust them to do is make sure they are in correct alphabetic order.
If you look at the xml so the order of them is important. I also know if I am
looking at a R### roll bin that I need 3 `<pathurl></pathurl>` and if im
looking inside G### I need 6 and for C### only 5.
The order of them is important as they can rename the name tag inside `~~~~ to
rename cameras that were the wrong setting without renaming source files.
(which breaks important metadata that is needed in other programs)
While in this part of the tree I'd also like to grab the `<clip
id=~><in>###</in>` to grab the in marker frame offset. If the cameras have
gone out of sync and their start points can be set. But of course this tag is
not child to the `<pathurl></pathurl>` and is actually 3 parents up! Also this
tag won't be on every clip so I can't look for it first!
<clip id="masterclip-40" explodedTracks="true" frameBlend="FALSE">
<uuid>85f87acc-308f-401e-bf82-55e8ea41e55a</uuid>
<masterclipid>masterclip-40</masterclipid>
<ismasterclip>TRUE</ismasterclip>
<duration>5355</duration>
<rate>
<timebase>30</timebase>
<ntsc>TRUE</ntsc>
</rate>
<in>876</in>
<name>B002_C002_0216AM_002.R3D</name>
<media>
<video>
<track>
<clipitem id="clipitem-118" frameBlend="FALSE">
<masterclipid>masterclip-40</masterclipid>
<name>B002_C002_0216AM_002.R3D</name>
<rate>
<timebase>30</timebase>
<ntsc>TRUE</ntsc>
</rate>
<alphatype>none</alphatype>
<pixelaspectratio>square</pixelaspectratio>
<anamorphic>FALSE</anamorphic>
<file id="file-40">
<name>B002_C002_0216AM_002.R3D</name>
<pathurl>file://localhost/Volumes/REDLAB_3A/SESQUI/MASTER_FILES/DAY_00/RED/R002/B002/B002_0216G4.RDM/B002_C002_0216AM.RDC/B002_C002_0216AM_002.R3D</pathurl>
So once I've parsed all this the information I'd like to have is.
* The original bin folder structure of the XML contained in the `daynumber`. Take the names of the bins and construct the same folder structure in the `nk_output_dir` (Day_00/R001/R001_C001 etc etc)
* I also want to make a `daynumber` directory in the `dnx_render_dir` folder and a directory for each bin referencing a camera roll.
* Based on if the clipname is starts with a R, G or C I want to be able to access that for selecting what kind of .nk to make.
* I want the pathurl information for each bin that is referring to a clip and plug. I also want any `<in>` information if there is any for that clip. That way I can plug it into the read node information for my nuke gizmo.
I think once I figure out how to parse such a complicated xml tree I'll able
to fuss and fumble the rest of the process.
I am just really struggling with finding examples of parsing an complicated
XML file like this.
Answer: Whenever faced with a complex XML, consider an XSLT script to transform your
XML into a simpler structure. As information,
[XSLT](https://www.w3.org/TR/xslt) is a special-purpose, declarative language
(same type as SQL) designed to transform XML into various structures for end
use needs. Python like other general purpose languages maintains an XSLT
processor, specifically in its [lxml](http://lxml.de/) module.
While this transformation does not address your entire needs, you can parse
the simpler structure for your Nuke application needs. Directories and names
are simplified and labeled for daynumber, rollnumber, shotnames, and clip with
pathurls.
**XSLT** script _(save as .xsl or .xslt to be referenced in .py script below)_
<xsl:transform xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">
<xsl:output version="1.0" encoding="UTF-8" indent="yes" />
<xsl:strip-space elements="*"/>
<xsl:key name="idkey" match="ctype" use="@id" />
<xsl:template match="/">
<root>
<xsl:apply-templates select="*"/>
</root>
</xsl:template>
<xsl:template match="xmeml/bin">
<daynumber><xsl:value-of select="name"/></daynumber>
<xsl:apply-templates select="children/bin"/>
</xsl:template>
<xsl:template match="xmeml/bin/children/bin">
<roll>
<rollnumber><xsl:value-of select="name"/></rollnumber>
<rollnumberdir><xsl:value-of select="concat(ancestor::bin/name,
'/', name)"/></rollnumberdir>
<xsl:apply-templates select="children/bin"/>
</roll>
</xsl:template>
<xsl:template match="xmeml/bin/children/bin/children/bin">
<shot>
<shotname><xsl:value-of select="name"/></shotname>
<shotnamedir><xsl:value-of select="concat(/xmeml/bin/name, '/',
/xmeml/bin/children/bin/name, '/', name)"/></shotnamedir>
<xsl:apply-templates select="descendant::clip[position() < 4]"/>
</shot>
</xsl:template>
<xsl:template match="clip">
<clip>
<clipname><xsl:value-of select="descendant::name"/></clipname>
<xsl:copy-of select="in"/>
<pathurl><xsl:value-of select="descendant::pathurl"/></pathurl>
</clip>
</xsl:template>
</xsl:transform>
**Python** script _(transform, parse, and export simpler structure)_
#!/usr/bin/python
import lxml.etree as ET
# LOAD INPUT XML AND XSLT
dom = ET.parse('Input.xml'))
xslt = ET.parse('XSLTScript.xsl')
# TRANSFORM XML (SIMPLER NEWDOM CAN BE FURTHER PARSED: ITER(), FINDALL(), XPATH())
transform = ET.XSLT(xslt)
newdom = transform(dom)
# XPATH EXPRESSIONS (LIST OUTPUTS)
daynumber = newdom.xpath('//daynumber/text()')
# ['Day_00']
rolls = newdom.xpath('//rollnumber/text()')
# ['R001', 'R002']
shots = newdom.xpath('//shotname/text()')
# ['R001_C001', 'R002_C001', 'R002_C002']
# CONVERT TO STRING (IF NEEDED)
tree_out = ET.tostring(newdom, encoding='UTF-8', pretty_print=True, xml_declaration=True)
print(tree_out.decode("utf-8"))
# OUTPUT TO FILE (IF NEEDED)
xmlfile = open('Output.xml'),'wb')
xmlfile.write(tree_out)
xmlfile.close()
**TRANSFORMED XML** _(contained in newdom object in .py script)_
<?xml version='1.0' encoding='UTF-8'?>
<root>
<daynumber>Day_00</daynumber>
<roll>
<rollnumber>R001</rollnumber>
<rollnumberdir>Day_00/R001</rollnumberdir>
<shot>
<shotname>R001_C001</shotname>
<shotnamedir>Day_00/R001/R001_C001</shotnamedir>
<clip>
<clipname>A002_C001_0216MW_001.R3D</clipname>
<pathurl>file://localhost/Volumes/REDLAB_3A/SESQUI/MASTER_FILES/DAY_00/RED/R001/A002/A002_0216FE.RDM/A002_C001_0216MW.RDC/A002_C001_0216MW_001.R3D</pathurl>
</clip>
<clip>
<clipname>A002_C001_0216MW_002.R3D</clipname>
<pathurl>file://localhost/Volumes/REDLAB_3A/SESQUI/MASTER_FILES/DAY_00/RED/R001/A002/A002_0216FE.RDM/A002_C001_0216MW.RDC/A002_C001_0216MW_002.R3D</pathurl>
</clip>
<clip>
<clipname>A002_C001_0216MW_003.R3D</clipname>
<pathurl>file://localhost/Volumes/REDLAB_3A/SESQUI/MASTER_FILES/DAY_00/RED/R001/A002/A002_0216FE.RDM/A002_C001_0216MW.RDC/A002_C001_0216MW_003.R3D</pathurl>
</clip>
</shot>
</roll>
<roll>
<rollnumber>R002</rollnumber>
<rollnumberdir>Day_00/R002</rollnumberdir>
<shot>
<shotname>R002_C001</shotname>
<shotnamedir>Day_00/R001/R002_C001</shotnamedir>
<clip>
<clipname>A003_C001_0216XI_001.R3D</clipname>
<pathurl>file://localhost/Volumes/REDLAB_3A/SESQUI/MASTER_FILES/DAY_00/RED/R002/A003/A003_0216XO.RDM/A003_C001_0216XI.RDC/A003_C001_0216XI_001.R3D</pathurl>
</clip>
<clip>
<clipname>B002_C001_02169H_002.R3D</clipname>
<pathurl>file://localhost/Volumes/REDLAB_3A/SESQUI/MASTER_FILES/DAY_00/RED/R002/B002/B002_0216G4.RDM/B002_C001_02169H.RDC/B002_C001_02169H_002.R3D</pathurl>
</clip>
<clip>
<clipname>C002_C001_02168R_001.R3D</clipname>
<pathurl>file://localhost/Volumes/REDLAB_3A/SESQUI/MASTER_FILES/DAY_00/RED/R002/C002/C002_0216RL.RDM/C002_C001_02168R.RDC/C002_C001_02168R_001.R3D</pathurl>
</clip>
</shot>
<shot>
<shotname>R002_C002</shotname>
<shotnamedir>Day_00/R001/R002_C002</shotnamedir>
<clip>
<clipname>C002_C002_0216M9_001.R3D</clipname>
<pathurl>file://localhost/Volumes/REDLAB_3A/SESQUI/MASTER_FILES/DAY_00/RED/R002/C002/C002_0216RL.RDM/C002_C002_0216M9.RDC/C002_C002_0216M9_001.R3D</pathurl>
</clip>
<clip>
<clipname>C002_C002_0216M9_002.R3D</clipname>
<pathurl>file://localhost/Volumes/REDLAB_3A/SESQUI/MASTER_FILES/DAY_00/RED/R002/C002/C002_0216RL.RDM/C002_C002_0216M9.RDC/C002_C002_0216M9_002.R3D</pathurl>
</clip>
<clip>
<clipname>C002_C002_0216M9_003.R3D</clipname>
<pathurl>file://localhost/Volumes/REDLAB_3A/SESQUI/MASTER_FILES/DAY_00/RED/R002/C002/C002_0216RL.RDM/C002_C002_0216M9.RDC/C002_C002_0216M9_003.R3D</pathurl>
</clip>
</shot>
</roll>
</root>
|
Why does my repository object return Nonetype with github3.py?
Question: Using github3.py version 0.9.5
[documentation](http://github3py.readthedocs.org/en/0.9.5/repos.html), I'm
trying to create a repository object but it keeps returning `Nonetype` and
therefore I am unable to access the contents of the repository. There doesn't
seem to be any other posts on StackOverflow, or conversations on the library's
GitHub issues that address this problem.
`AttributeError: 'NoneType' object has no attribute 'contents'` is the exact
error I received.
On the line that says `repo = repository('Django', auth)` I tried changing
**auth** with **fv4** but that doesn't change anything other.
#!/usr/bin/env python
from github3 import authorize, repository, login
from pprint import PrettyPrinter as ppr
import github3
from getpass import getuser
pp = ppr(indent=4)
username = 'myusername'
password = 'mypassword'
scopes = ['user', 'repo', 'admin:public_key', 'admin:repo_hook']
note = 'github3.py test'
note_url = 'http://github.com/FreddieV4'
print("Attemping authorization...")
token = id = ''
with open('CREDENTIALS.txt', 'r') as fi:
token = fi.readline().strip()
id = fi.readline().strip()
print("AUTH token {}\nAUTH id {}\n".format(token, id))
print("Attempting login...\n")
fv4 = login(username, password, token=token)
print("Login successful!", str(fv4), '\n')
print("Attempting auth...\n")
auth = fv4.authorization(id)
print("Auth successful!", auth, '\n')
print("Reading repo...\n")
repo = repository('Django', auth)
print("Repo object...{}\n\n".format(dir(repo)))
print("Repo...{}\n\n".format(repo))
contents = repo.contents('README.md')
pp.pprint('CONTENTS {}'.format(contents))
contents.update('Testing github3.py', contents)
#print("commit: ", commit)
Answer: So there are a few things up with your code, but let me help you with your
immediate problem first and then I'll move on to the other issues.
You're using `github3.repository` in the line you're confused about. Let's
look at the
[documentation](https://github3py.readthedocs.org/en/0.9.5/api.html#github3.repository)
for that specific function (which you can also see by calling
`help(repository)`). You'll see that `repository` expects two arguments
`owner` and `repository` and describes them as the owner of the repository and
the name of the repository itself. So in your usage you would do
repo = repository('Django', 'Django')
But where does that leave your authentication credentials... Well here's the
other thing, you're doing
fv4 = login(username, password, token)
You only need to specify some of those arguments. If you want to use a token
then do
fv4 = login(token=token)
Or if you want to use basic authentication
fv4 = login(username, password)
Both will work just fine. If you want to continue to be authenticated you can
then do
repo = fv4.repository('Django', 'Django')
Because `fv4` is a `GitHub` object which is documented
[here](https://github3py.readthedocs.org/en/0.9.5/github.html#github-object)
and which the `repository` function uses underneath everything.
So that should help you get through most of your problems.
* * *
Note that in the documented examples for github3.py we usually call the result
of `login()` `gh`. This is because `gh` is just a `GitHub` object with
credentials stored. It isn't your user or anything like that. That would be
(on your version of github3.py) `fv4 = gh.user()`. (If someone else is reading
this and using a version of github3.py 1.0 (currently in pre-release) then it
would be `fv4 = gh.me()`.)
|
Python random character string repeated 7/2000 records
Question: I am using the below to generate a random set of characters and numbers:
tag = ''.join([random.choice(string.ascii_letters + string.digits) for n in xrange(36)])
I thought that this was a decent method. 36 character length, with each
character being one of 36 unique options. Should be a good amount of
randomness, right?
Then, I was running a query off an instance with what I thought was a unique
`tag`. Turns out, there were **SEVEN (7)** records with the same "random"
`tag`. So, I opened the DB, and ran a query to see the repeatability of my
tags.
Turns out that not only does mine show up 7 times, but there are a number of
tags that repeatedly appear over and over again. With approximately 2000 rows,
it clearly should not be happening.
Two questions:
**(1) What is wrong with my approach, and why would it be repeating the
same`tag` so often?**
**(2) What would be a better approach to get unique tags for each record?**
Here is the code I am using to save this to the DB. While it is written in
Django, clearly this is not a django related question.
class Note(models.Model):
...
def save(self, *args, **kwargs):
import random
import string
self.tag = ''.join([random.choice(string.ascii_letters + string.digits) for n in xrange(36)])
super(Note, self).save(*args, **kwargs)
Answer: The problem with your approach:
1. true randomness/crypto is hard, you should try to use tested existing solutions instead of implementing your own.
2. Randomness isn't guaranteed - while 'unlikely', there's nothing preventing the same string to be generated more than once.
A better solution would be to not reinvent the wheel, and use the
[uuid](https://docs.python.org/2/library/uuid.html) module, a common solution
to generating unique identifiers:
import uuid
tag = uuid.uuid1()
|
Jinja2 templating not working in in Django 1.9
Question: Per the instructions on the [Django 1.9
tutorial](https://docs.djangoproject.com/en/1.9/topics/templates/#django.template.backends.jinja2.Jinja2)
I've added another file in the project root with the Environment settings -
from __future__ import absolute_import # Python 2 only
from django.contrib.staticfiles.storage import staticfiles_storage
from django.core.urlresolvers import reverse
from jinja2 import Environment
def environment(**options):
env = Environment(**options)
env.globals.update({
'static': staticfiles_storage.url,
'url': reverse,
})
return env`
(Granted to load the proper `jinja2` I had to rename the file something
differently, in this case `jinja2env.py` in project root)
And I updated `settings.py` with the new templating backend:
TEMPLATES = [
{
'BACKEND': 'django.template.backends.django.DjangoTemplates',
'DIRS': [os.path.join(PROJECT_ROOT, 'templates').replace('\\','/')],
'APP_DIRS': True,
'OPTIONS': {
'context_processors': [
'django.template.context_processors.debug',
'django.template.context_processors.request',
'django.contrib.auth.context_processors.auth',
'django.contrib.messages.context_processors.messages',
],
},
},
{
'BACKEND': "django.template.backends.jinja2.Jinja2",
'DIRS': [os.path.join(PROJECT_PATH, 'campaigns/templates').replace('\\','/')],
"APP_DIRS": True,
"OPTIONS": {
'environment': 'jinja2env.Environment',
}
},
In the view I'm working on I use the `using` parameter to specify the `jinja2`
templating engine:
return render(request, 'jinja2/index.html', context={'projects': projects, 'counter': 0}, status=200, using='jinja2')
Yet when the template goes to render I have following error: `'static' is
undefined`. Clearly my setup is wrong or I am not doing something correct. The
template starts as such:
<link rel="stylesheet" type="text/css" href="{{ static('stylesheets/main.css') }}">
What am I doing wrong? I don't use `{% load static %}` since it isn't a Django
template ... so I'm at a loss.
Answer: Based on your settings and the accepted answer to [this
question](http://stackoverflow.com/questions/6261823/static-url-not-working),
it appears you should try adding the `static` context processor.
|
Why is the ipython output of set different from the __repr__ or __str__ of the set?
Question: I am running the following code in ipython and am surprised at the print
outputs and the ipython cell outputs of the code:
print set(["A", "B", "C"])
print set(["A", "C", "B"])
print list(set(["A", "C", "B"]))
print list(set(["A", "B", "C"]))
print [k for k in set(["A", "C", "B"])]
print [k for k in set(["A", "B", "C"])]
a = set(["A", "B", "C"])
print a
print a.__repr__()
print a.__str__()
print [(k, hash(k)) for k in a]
a
The output of the above program is as follows:
set(['A', 'C', 'B'])
set(['A', 'C', 'B'])
['A', 'C', 'B']
['A', 'C', 'B']
['A', 'C', 'B']
['A', 'C', 'B']
set(['A', 'C', 'B'])
set(['A', 'C', 'B'])
set(['A', 'C', 'B'])
[('A', -269909568), ('C', -13908798), ('B', -141909181)]
Out[34]: {'A', 'B', 'C'}
Note, that the cell output is `{'A', 'B', 'C'}` while the printed output is
`set(['A', 'C', 'B'])`
My Python details are as follows:
import sys
print sys.version
2.7.11 |Anaconda 2.3.0 (64-bit)| (default, Jan 29 2016, 14:26:21) [MSC v.1500 64 bit (AMD64)]
Answer: IPython adds some magic from time-to-time to make things more readable.
In this case it's showing you a set literal (new in python2.7)
Here's the code that makes that happen:
<https://github.com/ipython/ipython/blob/f49962dc931870a1eba4b6467ce302c8ae095b3f/IPython/lib/pretty.py#L560>
|
Finding Term Frequency and Inverse Document Frequency Utilizng NLTK (Python 3.5)
Question: I'm trying to utilize NLTK to perform term frequency (TF) and inverse document
frequency (IDF) analyses on a batch of files (they happen to be corporate
press releases from IBM). I know that the assertion of whether or not NLTK has
TF IDF capabilities [has been disputed on SO
beforehand](http://stackoverflow.com/questions/29570207/does-nltk-have-tf-idf-
implemented), but I've found docs indicating the module does have them:
<http://www.nltk.org/_modules/nltk/text.html>
<http://www.nltk.org/api/nltk.html#nltk.text.TextCollection>
I've never seen or used "self" or **init** to execute code beforehand. This is
what I have so far. Any advice on how to amend this code so it works is very
much appreciated. What I currently have doesn't return anything. I don't
really understand what "source," "self" or "term" and "text" in the NLTK docs
represent.
import nltk.corpus
from nltk.text import TextCollection
from nltk.corpus import gutenberg
gutenberg.fileids()
ibm1 = gutenberg.words('ibm-github.txt')
ibm2 = gutenberg.words('ibm-alior.txt')
mytexts = TextCollection([ibm1, ibm2])
term = 'software'
def __init__(self, source):
if hasattr(source, 'words'):
source = [source.words(f) for f in source.fileids()]
self._texts = source
Text.__init__(self, LazyConcatenation(source))
self._idf_cache = {}
def tf(self, term, mytexts):
result = mytexts.count(term) / len(mytexts)
print(result)
Answer:
from nltk.text import TextCollection
from nltk.book import text1, text2, text3
mytexts = TextCollection([text1, text2, text3])
# Print the IDF of a word
print(mytexts.idf("Moby"))
# tf_idf
print(mytexts.tf_idf("Moby", text1))
|
'str' object has not attribute 'subs'
Question: Here is my Python code written in Vim. Whenever I run it, I get the error
`'str' object has not attribute 'subs'`
from sympy import *
x,a_test,b_test,fa_test,fb_test=symbols('x a_test b_test fa_test fb_test')
expr=raw_input("enter the equation")
print expr
print "hello"
try:
print "hello"
inc=0
a=inc
fa=expr.subs(x,inc)
print "hello"
if(fa<0):
print "hello"
inc+=1
fb=expr.subs(x,inc)
if(fb<=0):
while(fb<=0):
inc+=1
else:
print "hello"
inc+=1
fb=expr.subs(x,inc)
if(fb<=0):
while(fb<=0):
inc+=1
b=inc
print a
print b
print fa
print fb
except Exception,e:
print e
Answer: The return value of `raw_input` is a `str`; you cannot use it as if it is a
SymPy `expr`. You need to
[parse](http://docs.sympy.org/dev/modules/parsing.html) it first:
from sympy.parsing.sympy_parser import parse_expr
...
expr = parse_expr(raw_input("enter the equation"))
|
Printing out a proper bill producing program in python
Question: relatively new to programming in python, thank you for all the fast help that
was provided on my last question I had on another python project. Anyways, Ive
written a new program for a project in python that produces a bill for a
catering venue. This is my code below, everything runs fine, and I get the
intended results required for the project, The two problems I am experience
are, 1. I need the cost of the desert to not print---> 3.0 but ---> $3.00,
essentially, how can I print dollar signs, and round e.x 3.0 --> 3.00, or
45.0--> 45.00..and with dollar signs before prices. Sorry if something like
this has been asked..
import math
# constants
Cost_Per_Desert = 3.00
Tax_Rate = .075
Gratuity_Tips = .15
Adult_Meal_Cost = 12.75
Child_Meal_Cost = .60*12.75
Room_Fee = 450.00
Less_Deposit = 250.00
def main():
# Input Section
Name = input("\n\n Customer:\t\t\t ")
Number_Of_Adults = int(input(" Number of Adults:\t\t "))
Number_Of_Children = int(input(" Number of Children:\t\t "))
Number_Of_Deserts = int(input(" Number of Deserts:\t\t "))
print("\n\nCost Of Meal Per Adult:\t\t" , Adult_Meal_Cost)
print("Cost of Meal Per Child:\t\t" , round(Child_Meal_Cost,2))
print("Cost Per Desert:\t\t" , round(Cost_Per_Desert,2))
# Processing/Calculations
Total_Adult_Meal_Cost = Adult_Meal_Cost* Number_Of_Adults
Total_Child_Meal_Cost = Child_Meal_Cost* Number_Of_Children
Total_Desert_Cost = Cost_Per_Desert* Number_Of_Deserts
Total_Food_Cost = Total_Adult_Meal_Cost + Total_Child_Meal_Cost + Total_Desert_Cost
Total_Taxes = Total_Food_Cost * Tax_Rate
Tips = Total_Food_Cost * Gratuity_Tips
Total_Bill = Total_Food_Cost + Total_Taxes + Tips + Room_Fee
# Output Section
print("\n\n Total Cost for Adult Meals: \t", Total_Adult_Meal_Cost)
print(" Total Cost for Childs Meals: \t", Total_Child_Meal_Cost)
print(" Total Cost for Desert: \t", Total_Desert_Cost)
print(" Total Food Cost: \t\t", Total_Food_Cost)
print("\n\n Plus 7.5% Taxes: \t\t", round(Total_Taxes,2))
print(" Plus 15.0% Tips: \t\t", round(Tips,2))
print(" Plus Room Fee: \t\t", Room_Fee)
print("\n\n Total Bill: \t\t\t", round(Total_Bill,2))
print(" Less Deposit: \t\t\t", Less_Deposit)
print("\n\nBalance Due: \t\t\t", round(Total_Bill - Less_Deposit,2))
print("\n\n\n\n\t\t Thank You For Using Passaic County Catering Services. ")
main()
input("\n\n\n\n\nPress Enter to Continue")
Answer: Let's say cost of desert is $3.00
cost = 3
print("${0:.2f}".format(cost))
Output:
$3.00
|
sha1 collision of less than 512 bit
Question: In Wikipedia [SHA-1 pseudocode](https://en.wikipedia.org/wiki/SHA-1), it's
said:
> Pre-processing: append the bit '1' to the message e.g. by adding 0x80 if
> message length is a multiple of 8 bits. append 0 ≤ k < 512 bits '0', such
> that the resulting message length in bits
So is it same with `\x01` and `x00\x01`?
Python example:
import hashlib
for s in ('01', '0001'):
m=hashlib.sha1()
m.update(s.decode('hex'))
print m.hexdigest()
>>>bf8b4530d8d246dd74ac53a13471bba17941dff7
>>>0e356ba505631fbf715758bed27d503f8b260e3a
It turns out not to be the same, why?
Answer: **`\x01` and `\x0001` cannot be the same after pre-processing.**
I think that you misunderstand the pseudocode in
[Wiki](https://en.wikipedia.org/wiki/SHA-1). Here I take `\x01` and `\x0001`
as examples, which their length are less than `512` bits.
(Now suppose that the original message length is less than `448` bits)
* first step: fill in to let its length **=448 (mod 512)**. We append the `1` bit first, then append `0`.
Thus, for `\x01`, it becomes `\x01800000...000`, and its length is 448 bits,
and the ellipsis represents `0` in **hex**.
* second step: fill in the length. We should add the reminder `(512 - 448) = 64` bits to represent its original length.
Thus, for `\x01`, its original length is `8`, it shall append `\x00000000
00000008`.
From mentioned above, after pre-processing, `\x01` becomes `\x01800000...08`,
and whole length is 512, and the ellipsis represents `0` in **hex**.
|
Python - Unzip .gz files in parallel
Question: I have multiple .gz files that add up to 1TB in total. How can I utilize
Python 2.7 to unzip these files in parallel? looping on the files takes too
much time.
I tried this code as well:
filenames = [gz for gz in glob.glob(filesFolder + '*.gz')]
def uncompress(path):
with gzip.open(path, 'rb') as src, open(path.rstrip('.gz'), 'wb') as dest:
shutil.copyfileobj(src, dest)
with multiprocessing.Pool() as pool:
for _ in pool.imap_unordered(uncompress, filenames, chunksize=1):
pass
However I get the following error:
with multiprocessing.Pool() as pool:
AttributeError: __exit__
Thanks!
Answer: To use `with` construct, the object used inside must have `__enter__` and
`__exit__` methods. The error says that the `Pool` class (or instance) doesn't
have these so you can't use it in the `with` statement. Try this (just removed
the with statement):
import glob, multiprocessing, shutil
filenames = [gz for gz in glob.glob('.' + '*.gz')]
def uncompress(path):
with gzip.open(path, 'rb') as src, open(path.rstrip('.gz'), 'wb') as dest:
shutil.copyfileobj(src, dest)
for _ in multiprocessing.Pool().imap_unordered(uncompress, filenames, chunksize=1):
pass
**EDIT**
I agree with @dhke, unless all (or most) of gz files are physically located
adjacently, frequent disk reads for different locations (which are called more
frequently when using multiprocessing) will be slower as compared to doing
these operations file by file one by one (serially).
|
moving average of 3 elements by C or Python
Question: I want to calculate the moving average of 3 elements.
For example, I have a 25 elements of sales data. I need to calculate the
moving average taken from averaging these 25 elements of data.
When a real array is given as data, I want to write a program that will
determines a 3 element moving average and creates an array. The number of
elements in the array becomes 2 elements shorter than the given sequence. For
example, if I am given:
[7.0, 9.0, 5.0, 1.0, 3.0]
I want to get:
[7.0, 5.0, 3.0]
Answer: The best (and fastest, by far) way to approach this is
[convolution](https://en.wikipedia.org/wiki/Convolution). Using [numpy's
convolve](http://docs.scipy.org/doc/numpy-1.10.0/reference/generated/numpy.convolve.html):
import numpy as np
x = np.asarray([7.0, 9.0, 5.0, 1.0, 3.0])
# create what's known as the convolution 'kernel'
# note that this sums to 1, which results in an average
kernel = np.ones(3) / 3
# do the convolution to compute the moving average
moving_avg = np.convolve(x, kernel, mode='valid')
You can view the convolution operation as the kernel "sliding" over the data
sequence. Every point `moving_avg[k]` in the output of the convolution will be
the area under the product between your data and the kernel, when the kernel
is centered at that point `k`.
This is an animation (from the wikipedia article linked above) illustrating
the principle for the square kernel used in moving average computation:
[](http://i.stack.imgur.com/9truS.gif)
|
How to remove an app from a django projects (and all its tables)
Question: I want to remove an app from a django project.
I want to remove
* the tables of the app
* the content-types
* foreign-key usages of these content-types
Running `manage.py migrate app_to_remove zero` does not work:
django.db.migrations.migration.IrreversibleError:
Operation <RunPython <function forwards_func at 0x7ff76075d668>> in
fooapp.0007_add_bar is not reversible
I guess there are several migrations which are not reversible ...
Answer: # First: Remove references in the code
* remove `app_to_remove` from `settings.INSTALLED_APPS`
* remove other references in `urls.py` or other places
# Second: Clean the database
Create an empty migration for your django-project:
manage.py makemigrations your_django_project --empty
Edit the file. Here is a template:
# -*- coding: utf-8 -*-
from __future__ import unicode_literals
from django.db import migrations, models
class Migration(migrations.Migration):
dependencies = [
('your_django_project', '0001_initial'),
]
operations = [
migrations.RunSQL('''
drop if exists table app_to_remove_table1;
drop if exists table app_to_remove_table2;
....
delete from auth_permission where content_type_id in (select id from django_content_type where app_label = '{app_label}');
delete from django_admin_log where content_type_id in (select id from django_content_type where app_label = '{app_label}');
delete from reversion_version where content_type_id in (select id from django_content_type where app_label = '{app_label}');
delete from django_content_type where app_label = '{app_label}';
delete from django_migrations where app='{app_label}';
'''.format(app_label='app_to_remove'))
]
Run the migration, run tests.
About "drop if exists": You have two cases:
1. The production system: You want to drop the tables.
2. New development systems: These systems never had this app, and they don't have this table :-)
|
Replace 4-5 lines of a large text file using python
Question: I have a text file in which i need to change
USER PROMPT [Program SIM GENTEST05]
<Description />
<MultiPartMessage>false</MultiPartMessage>
<NumberOfMultiParts>0</NumberOfMultiParts>
<Commented>false</Commented>
<ProgrammingCmdData xsi:type="UserPromptData">
<Prompt>Program SIM GENTEST05</Prompt>
with some customize values. I need some hint to do it in python 2.7
Answer: I would use the [fileinput](https://docs.python.org/2/library/fileinput.html)
library, it would be something like this:
import sys
import fileinput
for i, line in enumerate(fileinput.input('lorem_ipsum.txt', inplace=1)):
if "<MultiPartMessage>" in line:
sys.stdout.write(line.replace(
'<MultiPartMessage>false</MultiPartMessage>',
'<MultiPartMessage>something</MultiPartMessage>'))
elif "<NumberOfMultiParts>" in line:
sys.stdout.write(line.replace(
'<NumberOfMultiParts>0</NumberOfMultiParts>',
'<NumberOfMultiParts>something</NumberOfMultiParts>'))
else
sys.stdout.write(line)
|
Importing from a git sub-module (ImportError)
Question: I get an `ImportError` when I am importing from a sub-module in the way I
thought One Was Supposed To Do It.
I have the following package:
pkg/
__init__.py
cow.py
pizza.py
pkg.py
components/
components.py
otherstuff.py
__init__.py
cow.py:
print "Hello"
from components import foodle
components.py:
foodle=5
and the `__init__`'s are empty.
I am having trouble putting things in the right place or organizing them
properly. When, from the pkg directory, I try
from pkg import foodle
I get "ImportError: cannot import name foodle"
What is the right way to arrange files and import from submodules? I have read
[How to import python file from git
submodule](http://stackoverflow.com/questions/29746958/how-to-import-python-
file-from-git-submodule) ; I have tried messing with `sys.path` in
`components/__init__.py` and in `cow.py`, to no avail. This package is shared
on git, so it needs to be portable. `components` is actually a git sub-module.
Putting `from components import *` in the `__init__py` in components/ seems to
work, but I thought usually that file stays empty.
Answer: The elements I was missing are (these are my interpretation, may still be
incorrect):
* If it's a package (with `__init__.py`), use it from outside the `pkg` folder, not from inside. ie, using a package both ways (calling from outside and using modules from within) might be hard to set up, so don't. This is the main insight that solves my problem.
* the dot notation for getting submodules and subpackages works both for files and for folders within `pkg`. Thus, from some other folder, but with `pkg` in my path, I can call any of the following:
import pkg from pkg.cow import foodle from pkg.components import foodle from
pkg.components.components import foodle
|
Amino acid sequences in pyplot (Same regions in both sequences)
Question: I'm beginner at python, and need your help :) I have to compare two sequences,
when amino acid is similar at both sequences (doesn't matter which position it
is) program should put in into graph as point.
For example: If we have two sequences
x=['M','N','K','M']
y=['M','K','M']
Program should tick a point in position (1,1) (because of 2 M's), (1,3)
(same), (3,2) (because of 2 K's), (4,1) and (4,1)
At finish, with bigger sequence it should looks like that:
<http://wrzucaj.net/images/2016/03/02/853cd842715edd881296c804502d475b.png>
But i stuck, the effect of my works looks like that:
<http://wrzucaj.net/images/2016/03/02/005862962dea7e3a6eb24f3449704ef5.png>
In left side and bottom, there should be shown sequence which is covered by
other amino acids, i don't know why.
# Importing
import wx
import matplotlib.pyplot as plt
## And this is how program looks like:
def pajplot(evt):
Ktory1=Lista.GetSelection()
Ktory2=Listaa.GetSelection()
a=Sekwencje[Ktory1][3]
b=Sekwencje[Ktory2][3]
x1=[]
y1=[]
x2=[]
y2=[]
for i in range(30):
for j in range(30):
if a[i]==b[j]:
x1.append(i)
y1.append(j)
else:
x2.append(i)
y2.append(j)
Sekwencja1=[]
Sekwencja2=[]
for i in range(30):
Sekwencja1.append(a[i])
for j in range(30):
Sekwencja2.append(b[j])
plt.plot(x1 ,y1, 'ko')
plt.plot(x2 ,y2, 'wo')
plt.xticks(x1, Sekwencja1,'ko')
plt.yticks(y1, Sekwencja2,'wo')
plt.show()
Where Sekwencje is list, which have lists inside with names, etc and sequence
at 4 place. I tried to make it for 30 amino acids at start.
No need full answer, could be only a little hint.
Thank you in Advance.
Answer: It looks like you are putting x- and y-ticks only at the coordinates of your
matched amino acids. But you are using all the amino acid letters.
It is not entirely clear whether you want all of the labels (in their proper
places) or only labels where you find a match. So you could do **one** of
those two things depending on what you want:
**Only put labels where there are matches** : In that case you need to change
your definitions of `Sekwencja` 1 and 2:
Sekwencja1 = [a[i] for i in x1]
Sekwencja2 = [b[j] for j in y1]
**Put labels on everything** : In this case you need to use `range(30)`
instead of `x1` and `y1` when setting the ticks:
plt.xticks([range(30)], Sekwencja1,'ko')
plt.yticks([range(30)], Sekwencja2,'wo')
|
Find and rename files using a Python script
Question: I am new to Python coding so here a question. I want to find files that are
called "untitled" with any kind of extension, e.g. jpg, indd, psd. Then rename
them to the date of the current day.
I have tried the following:
import os
for file in os.listdir("/Users/shirin/Desktop/Artez"):
if file.endswith("untitled.*"):
print(file)
When I run the script, nothing happens.
Answer: You might find the
[`glob`](https://docs.python.org/3.5/library/glob.html?highlight=glob.glob#glob.glob)
function more useful in this situation:
import glob
for file in glob.glob("/Users/shirin/Desktop/Artez/untitled.*"):
print(file)
Your function does not print anything as there are probably no files ending
with `.*` in the name. The `glob.glob()` function will carry out the file
expansion for you.
You can then use this to do your file renaming as follows:
import glob
import os
from datetime import datetime
current_day = datetime.now().strftime("%Y-%m-%d")
for source_name in glob.glob("/Users/shirin/Desktop/Artez/untitled.*"):
path, fullname = os.path.split(source_name)
basename, ext = os.path.splitext(fullname)
target_name = os.path.join(path, '{}{}'.format(current_day, ext))
os.rename(source_name, target_name)
|
installing Theano with Enthought Canopy on Windows
Question: I'm trying to install Theano, here is my situation.
The system is Windows 10 (64-bit), with CUDA 7.5 installed with Visual Studio
2013. The Python distribution is Enthought Canopy (2.7.10, 32-bit) with pip,
numpy (1.9.2-3) and scipy (0.17.0-2).
The installation is as follows, 1\. install Theano (0.7) with pip; 2\. install
mingw (4.8.1-2) and libpython (1.2) using enpkg tool; 3\. copy the newly
created libpython27.a into ${PYTHONHOME}/Libs; 4\. edit and save .theanorc.txt
under c:\users\${myName} as
[global]
devive=gpu
floatX=float32
[blas]
ldflags=${PYTHONHOME}\Scripts -lmk2_core -lmk2_intel_thread -lmk2_rt
[nvcc]
flags=-LC:\Users\${myName}\AppData\Local\Enthought\Canopy32\User\libs
compiler_bindir=C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\bin
[gcc]
cxxflags=
When I try to import theano, I get the following warning and error:
> mod.cu(1019): warning: statement is unreachable
>
> mod.cu(1019): warning: statement is unreachable
>
> mod.cu LINK : fatal error LNK1181: cannot open input file 'cublas.lib'
>
> ['nvcc', '-shared', '-O3',
> '-LC:\Users\${myName}\AppData\Local\Enthought\Canopy32\User\libs', '--
> compiler-bindir', 'C:\Program Files (x86)\Microsoft Visual Studio
> 12.0\VC\bin', '-Xlinker', '/DEBUG', '-D HAVE_ROUND', '-m32', '-Xcompiler',
> '-DCUDA_NDARRAY_CUH=11b90075e2397c684f9dc0f7276eab8f,-D
> NPY_NO_DEPRECATED_API=NPY_1_7_API_VERSION,/Zi,/MD',
> '-IC:\Users\${myName}\AppData\Local\Enthought\Canopy32\User\lib\site-
> packages\theano\sandbox\cuda',
> '-IC:\Users\${myName}\AppData\Local\Enthought\Canopy32\App\appdata\canopy-1.6.2.3262.win-x86\lib\site-
> packages\numpy\core\include',
> '-IC:\Users\${myName}\AppData\Local\Enthought\Canopy32\App\appdata\canopy-1.6.2.3262.win-x86\include',
> '-o',
> 'C:\Users\${myName}\AppData\Local\Theano\compiledir_Windows-8-6.2.9200-Intel64_Family_6_Model_71_Stepping_1_GenuineIntel-2.7.10-32\cuda_ndarray\cuda_ndarray.pyd',
> 'mod.cu', '-LC:\Users\${myName}\AppData\Local\Enthought\Canopy32\User\EGG-
> INFO\mingw\usr\x86_64-w64-mingw32\lib',
> '-LC:\Users\${myName}\AppData\Local\Enthought\Canopy32\App\appdata\canopy-1.6.2.3262.win-x86\libs',
> '-LC:\Users\${myName}\AppData\Local\Enthought\Canopy32\App\appdata\canopy-1.6.2.3262.win-x86',
> '-lpython27', '-lcublas', '-lcudart']
>
> ERROR (theano.sandbox.cuda): Failed to compile cuda_ndarray.cu: ('nvcc
> return status', 2, 'for cmd', 'nvcc -shared -O3
> -LC:\Users\${myName}\AppData\Local\Enthought\Canopy32\User\libs --compiler-
> bindir C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\bin -Xlinker
> /DEBUG -D HAVE_ROUND -m32 -Xcompiler
> -DCUDA_NDARRAY_CUH=11b90075e2397c684f9dc0f7276eab8f,-D
> NPY_NO_DEPRECATED_API=NPY_1_7_API_VERSION,/Zi,/MD
> -IC:\Users\${myName}\AppData\Local\Enthought\Canopy32\User\lib\site-
> packages\theano\sandbox\cuda
> -IC:\Users\${myName}\AppData\Local\Enthought\Canopy32\App\appdata\canopy-1.6.2.3262.win-x86\lib\site-
> packages\numpy\core\include
> -IC:\Users\${myName}\AppData\Local\Enthought\Canopy32\App\appdata\canopy-1.6.2.3262.win-x86\include
> -o
> C:\Users\${myName}\AppData\Local\Theano\compiledir_Windows-8-6.2.9200-Intel64_Family_6_Model_71_Stepping_1_GenuineIntel-2.7.10-32\cuda_ndarray\cuda_ndarray.pyd
> mod.cu -LC:\Users\${myName}\AppData\Local\Enthought\Canopy32\User\EGG-
> INFO\mingw\usr\x86_64-w64-mingw32\lib
> -LC:\Users\${myName}\AppData\Local\Enthought\Canopy32\App\appdata\canopy-1.6.2.3262.win-x86\libs
> -LC:\Users\${myName}\AppData\Local\Enthought\Canopy32\App\appdata\canopy-1.6.2.3262.win-x86
> -lpython27 -lcublas -lcudart')
>
> WARNING (theano.sandbox.cuda): CUDA is installed, but device gpu is not
> available (error: cuda unavilable)
I'm wondering if it's the 32-bit Python vs 64-bit system that causes the
problem.
Answer: As @Robert point out in the comment, the warning suggests compatibility issue.
I finally solved the problem by installing the 64-bit Enthought Canopy python
distribution, the other steps are the same as described in the question.
It's worth mentioning that mingw can be installed by Enthough Canopy package
manager as well, so you don't have to download independent mingw if you are
using the distribution.
|
WARNING:oauth2client.util:build() takes at most 2 positional arguments (3 given)
Question: I am doing the "Label Detection" tutorial for the Google Cloud Vision API.
When I pass an image to the command like so I expect to get back some json
telling me what is in the image.
However, I am getting this error instead.
>python label_request.py faulkner.jpg
No handlers could be found for logger "oauth2client.util"
WARNING:root:No module named locked_file
Traceback (most recent call last):
File "/usr/local/lib/python2.7/site-packages/googleapiclient/discovery_cache/__init__.py", line 38, in autodetect
from . import file_cache
File "/usr/local/lib/python2.7/site-packages/googleapiclient/discovery_cache/file_cache.py", line 32, in <module>
from oauth2client.locked_file import LockedFile
ImportError: No module named locked_file
Traceback (most recent call last):
File "label_request.py", line 44, in <module>
main(args.image_file)
File "label_request.py", line 18, in main
service = build('vision', 'v1', http, discoveryServiceUrl=API_DISCOVERY_FILE)
File "/usr/local/lib/python2.7/site-packages/oauth2client/util.py", line 140, in positional_wrapper
return wrapped(*args, **kwargs)
File "/usr/local/lib/python2.7/site-packages/googleapiclient/discovery.py", line 202, in build
raise e
googleapiclient.errors.HttpError: <HttpError 403 when requesting https://vision.googleapis.com/$discovery/rest?version=v1 returned "Project has not activated the vision.googleapis.com API. Please enable the API for project google.com:cloudsdktool (#32555940559).">
Lots going on here.
But the Project API _is_ enabled.
So this is part of the error message is erroneous.
It seems that "there was a change in the newest version of the oauth2client,
v2.0.0, which broke compatibility with the google-api-python-client module".
<http://stackoverflow.com/a/35492604/2341218>
I applied this fix ...
pip install --upgrade git+https://github.com/google/google-api-python-client
After applying this fix, I get fewer errors ...
>python label_request.py faulkner.jpg
No handlers could be found for logger "oauth2client.util"
Traceback (most recent call last):
File "label_request.py", line 44, in <module>
main(args.image_file)
File "label_request.py", line 18, in main
service = build('vision', 'v1', http, discoveryServiceUrl=API_DISCOVERY_FILE)
File "/usr/local/lib/python2.7/site-packages/oauth2client/util.py", line 137, in positional_wrapper
return wrapped(*args, **kwargs)
File "/usr/local/lib/python2.7/site-packages/googleapiclient/discovery.py", line 209, in build
raise e
googleapiclient.errors.HttpError: <HttpError 403 when requesting https://vision.googleapis.com/$discovery/rest?version=v1 returned "Project has not activated the vision.googleapis.com API. Please enable the API for project google.com:cloudsdktool (#32555940559).">
It appears that this error message: "No handlers could be found for logger
"oauth2client.util" is actually masking a more detailed warning/error message
and that I can see the more detailed one by adding this code ...
import logging
logging.basicConfig()
<http://stackoverflow.com/a/29966147/2341218>
>python label_request.py faulkner.jpg
WARNING:oauth2client.util:build() takes at most 2 positional arguments (3 given)
Traceback (most recent call last):
File "label_request.py", line 47, in <module>
main(args.image_file)
File "label_request.py", line 21, in main
service = build('vision', 'v1', http, discoveryServiceUrl=API_DISCOVERY_FILE)
File "/usr/local/lib/python2.7/site-packages/oauth2client/util.py", line 137, in positional_wrapper
return wrapped(*args, **kwargs)
File "/usr/local/lib/python2.7/site-packages/googleapiclient/discovery.py", line 209, in build
raise e
googleapiclient.errors.HttpError: <HttpError 403 when requesting https://vision.googleapis.com/$discovery/rest?version=v1 returned "Project has not activated the vision.googleapis.com API. Please enable the API for project google.com:cloudsdktool (#32555940559).">
So no I am stuck on this error message:
WARNING:oauth2client.util:build() takes at most 2 positional arguments (3
given)
It has been suggested that this error can be avoided by using named parameters
instead of positional notation.
<http://stackoverflow.com/a/16643215/2341218>
However, I am uncertain exactly where I might make this change.
I don't actually see the oauth2client.util:build() function in the code.
Here is the google code (slightly modified):
>cat label_request.py
import argparse
import base64
import httplib2
from apiclient.discovery import build
from oauth2client.client import GoogleCredentials
import logging
logging.basicConfig()
def main(photo_file):
'''Run a label request on a single image'''
API_DISCOVERY_FILE = 'https://vision.googleapis.com/$discovery/rest?version=v1'
http = httplib2.Http()
credentials = GoogleCredentials.get_application_default().create_scoped(
['https://www.googleapis.com/auth/cloud-platform'])
credentials.authorize(http)
service = build('vision', 'v1', http, discoveryServiceUrl=API_DISCOVERY_FILE)
with open(photo_file, 'rb') as image:
image_content = base64.b64encode(image.read())
service_request = service.images().annotate(
body={
'requests': [{
'image': {
'content': image_content
},
'features': [{
'type': 'LABEL_DETECTION',
'maxResults': 1,
}]
}]
})
response = service_request.execute()
label = response['responses'][0]['labelAnnotations'][0]['description']
print('Found label: %s for %s' % (label, photo_file))
return 0
if __name__ == '__main__':
parser = argparse.ArgumentParser()
parser.add_argument(
'image_file', help='The image you\'d like to label.')
args = parser.parse_args()
main(args.image_file)
Answer: I've had the exactly same problem and I just solved doing this code line (you
have to have gcloud installed):
gcloud auth activate-service-account --key-file <service-account file.json>
and then:
$ export GOOGLE_APPLICATION_CREDENTIALS=<path_to_service_account_file>
Hope that helps!
|
python 'TypeError: argument must be string or read-only character buffer, not tuple'
Question: I wrote this code using python 2.7:
class LoadBalancerHandler:
def __init__(self, file_name):
self.server_socket = socket.socket(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
file = open(file_name)
setup_apps(file.read())
def listen(self, host='localhost', port=80):
self.server_socket.bind((host,port))
self.server_socket.listen(5)
while True:
(client_socket, address) = self.server_socket.accept()
threadHandling = ThreadHandling(client_socket, self)
threadHandling.start()
but I get this error:
> TypeError: argument must be string or read-only character buffer, not tuple
This error is raised by the line:`self.server_socket.bind((host,port))`
Answer: Again, i think your options to socket.socket(...) are incorrect. If you're
trying to create a TCP listener, this works
import socket
s = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
s.bind(('localhost',5555))
s.listen(5)
|
How to reshape this array with numpy?
Question: My file looks like this
3.766204987418e+00 3.016098278453e+00 2.882128625608e+00 2.789447648712e+00 2.704276250639e+00
2.540138572067e+00 2.318587560199e+00 2.272640952350e+00 2.138794921589e+00
I have also code to read it
import numpy as np
zxyr=[]
with open('det.txt') as f:
zxyr=list(f)
c=np.asarray(zxyr)
print c.shape
print len(c)
which produces
(2,)
2
How to reshape array to have (9,) shape?
EDIT I have tried
import numpy as np
c = np.loadtxt('det.txt')
print (c.shape)
BUt
Traceback (most recent call last):
File "kiev.py", line 3, in <module>
c = np.loadtxt('det.txt')
File "/usr/lib/python2.7/dist-packages/numpy/lib/npyio.py", line 856, in loadtxt
X = np.array(X, dtype)
ValueError: setting an array element with a sequence.
Answer: As @B.M. said in the comments you need to use `np.loadtxt`. As shown below:
import numpy as np
c = np.loadtxt('mytextfile.txt)
print (c.shape)
This gets the data from the file and puts it into a numpy array. If the text
file in my example is the same as yours then it will have the shape `(9,)` as
you require.
Another method you can do is the following:
with open('mytextfile.txt') as f:
content = f.readlines()
|
Incompatible GraphDef versions in Extend
Question: I have some code which creates a graph to process some images and then
iterates `sess.run()` in a loop to fetch batches of image tensors of shape [*,
299, 299, 3]. I'd like to then feed these images into the inception model.
So, I added some code to load the inception model:
def create_graph():
""""Creates a graph from saved GraphDef file and returns a saver."""
# Creates graph from saved graph_def.pb.
print 'Loading graph...'
with tf.Session() as sess:
with gfile.FastGFile('/web/tensorflow_transfer/resources/classify_image_graph_def.pb', 'rb') as f:
graph_def = tf.GraphDef()
graph_def.ParseFromString(f.read())
_ = tf.import_graph_def(graph_def, name='')
return sess.graph
g = create_graph()
for i in range(training_steps):
sess.run(...)
Now Im getting this error when running `run()`:
File "/usr/local/lib/python2.7/site-packages/tensorflow/python/client/session.py", line 368, in run
results = self._do_run(target_list, unique_fetch_targets, feed_dict_string)
File "/usr/local/lib/python2.7/site-packages/tensorflow/python/client/session.py", line 420, in _do_run
raise RuntimeError(compat.as_text(tf_session.TF_Message(status)))
RuntimeError: Incompatible GraphDef versions in Extend: 1 != 0
Answer: This is most likely from using too old a version of TensorFlow to read in and
run the graph -- the graph was created using a newer version of the GraphDef.
Try upgrading to 0.7 or to HEAD and then run your code again.
|
Executing R script with Python via subprocess.call
Question: I have a R script which works fine on its own but I need it to be a part of
python script. So, when I run the python script the R script be executed
automatically. I use the below command; there is no error but the R script
output files are not created.
import subprocess
retcode = subprocess.call("C:/Program Files/R/R-3.2.2/bin/Rscript --vanilla T:/2012.R", shell=True)
Thank you so much in advance.
Answer: Simply place your string command in brackets and break string into separate
components as the first parameter of function expects a list of arguments, per
the [doc](https://docs.python.org/2/library/subprocess.html):
> subprocess.call(args, *, stdin=None, stdout=None, stderr=None, shell=False)
import subprocess
retcode = subprocess.call(['C:/Program Files/R/R-3.2.2/bin/Rscript', '--vanilla',
'T:/2012.R'], shell=True)
Alternatively, break it up into multiple strings:
command = 'C:/Program Files/R/R-3.2.2/bin/Rscript'
arg = '--vanilla'
path2script = 'T:/2012.R'
retcode = subprocess.call([command, arg, path2script], shell=True)
|
How to prevent a QDoubleSpinBox from changing values
Question: I've written a GUI for a script that does some geometrical calculations.
Certain ranges of values break the computation (e.g. find the intersection of
two shapes that don't intersect.) I raise exceptions in those cases. I'd like
to prevent the user from adjusting the spinbox value beyond the point where
exceptions are raised.
I've tried overwriting the validator method for the QDoubleSpinBox. This works
great when I manually enter values with the keyboard. But, it doesn't prevent
me from clicking the up and down arrows.
How I can limit the ability of the user to run-up the values outside of the
acceptable range?
Note: The actual `some_complicated_function` involves the values from 5
different spinboxes.
from PyQt4 import QtCore, QtGui
import sys
def some_complicated_function(val_a):
if val_a + 3 < 10:
return True
else:
raise Exception("Giant number!")
class SpinBoxSpecial(QtGui.QDoubleSpinBox):
def validate(self, value, pos):
# print float(value)
try:
some_complicated_function(float(value))
print "yup"
return QtGui.QValidator.Acceptable, QtGui.QValidator.Acceptable
except:
print "nope"
return QtGui.QValidator.Invalid, QtGui.QValidator.Invalid
a = QtGui.QApplication(sys.argv)
w = QtGui.QMainWindow()
w.resize(320, 100)
w.setWindowTitle("PyQT Python Widget!")
spinbox = SpinBoxSpecial(w)
spinbox.move(20, 20)
spinbox.CorrectionMode = QtGui.QAbstractSpinBox.CorrectToPreviousValue
w.show()
sys.exit(a.exec_())
**Edit:** The basic ask is: I want to call a function when the value of a
spinbox changes (via mouse or keyboard). If that function throws an exception,
I want the value of the spinbox to revert to what it was.
Answer: Here is a simple way to dynamically set the range on a spinbox:
class SpinBoxSpecial(QtGui.QDoubleSpinBox):
def __init__(self, parent=None):
super(SpinBoxSpecial, self).__init__(parent)
self._last = self.value()
self.valueChanged.connect(self.handleValueChanged)
def handleValueChanged(self, value):
try:
some_complicated_function(float(value))
print "yup", value
self._last = value
except:
print "nope", value
if value > self._last:
self.setMaximum(self._last)
else:
self.setMinimum(self._last)
**EDIT** :
Just realized the above won't work correctly if a value is typed in directly,
because it could fix the min/max too early. So maybe this would be better:
def handleValueChanged(self, value):
try:
some_complicated_function(float(value))
print "yup", value
self._last = value
except:
print "nope", value
self.setValue(self._last)
|
Plotting to browser continuously using serve_figure
Question: I want to see plots in progress continuously driven by the plot program using
browser whenever it is connected. I searched and found serve_figure.py
examples that are similar to what I need. But I cant get the following test
code to work. Serve_figure.py holds up the for-loop after the first plot. At
the browser only the first plot is shown. I don't need the mouse event in
serve_figure.py. If there is another way to do this will be most welcome.
#!/usr/bin/env pythonnter
import serve_figure
import time
import numpy as np
import matplotlib
matplotlib.use('TkAgg')
import matplotlib.pyplot as plt
fig, ax = plt.subplots()
def animate():
x = np.arange(0, 2*np.pi, 0.01)
line, = ax.plot(x, np.sin(x))
for i in np.arange(1,200):
line.set_ydata(np.sin(x+i/10.0))
fig.canvas.draw()
time.sleep(1)
serve_figure.serve_figure(fig, port=8888)
win = fig.canvas.manager.window
fig.canvas.manager.window.after(200, animate)
plt.show()
Answer: BTW, the link to serve_figure.py is
<https://github.com/mdboom/mpl_browser_experiments/blob/master/serve_figure.py>
|
Django won't create a table for one model of many in an app
Question: _I'm using Django 1.9_
For whatever reason, I simply cannot get Django to create a table for any more
models in my `products` app. After I added the `store` model and registered it
on `admin.py` and running `manage.py makemigrations` & `manage.py migrate`
**countless** times, I tried adding instances to which I got a `Operation
error: no such table products_store`.
I have the following `models.py`:
from __future__ import unicode_literals
from django.db import models
# Create your models here.
def image_upload_location(instance, filename):
print instance.name
print filename
return "static/images/products/%s" %(filename)
class Category(models.Model):
title = models.CharField(max_length=120, unique=True)
description = models.TextField(null=True,blank=True)
def __unicode__(self):
return self.title
class Product(models.Model):
name = models.CharField(max_length = 120)
description = models.TextField(blank=True,null=True)
main_image = models.ImageField(upload_to=image_upload_location)
price = models.DecimalField(decimal_places=2, max_digits=20)
available = models.BooleanField(default=True)
categories = models.ManyToManyField('Category', blank=True)
def __unicode__(self):
return self.name
class Store(models.Model):
name = models.CharField(max_length=120)
description = models.TextField(blank=True,null=True)
def __unicode__(self):
return self.name
class Building(models.Model):
name = models.CharField(max_length=30)
class Variant(models.Model):
variant_name = models.CharField(max_length=120)
description = models.TextField(blank=True,null=True)
variant_image = models.ImageField(upload_to=image_upload_location, null=True)
price = models.DecimalField(decimal_places=2,max_digits=20)
available = models.BooleanField(default=True)
product = models.ForeignKey(Product)
store = models.ForeignKey(Store)
def __unicode__(self):
return self.variant_name
Then on the shell, I tried the following:
In [1]: from products.models import Store
In [2]: from products.models import Product
In [3]: Store
Out[3]: products.models.Store
In [4]: Product
Out[4]: products.models.Product
In [5]: Store.objects.all()
OperationalError: no such table: products_store
In [8]: Product.objects.all()
Out[8]: []
Seems really strange to me. I also tried deleting all the migrations, and then
running all the migrations again, but that didn't seem to work.
Here's the output from the migrations:
Migrations for 'products':
0001_initial.py:
- Create model Category
- Create model Product
- Create model Store
- Create model Variant
A:try3 a$ python manage.py migrate
Operations to perform:
Apply all migrations: sessions, admin, sites, auth, contenttypes, products
Running migrations:
Rendering model states... DONE
Applying sites.0001_initial... OK
Applying sites.0002_alter_domain_unique... OK
**Update:** Output from `manage.py dbshell`
SQLite version 3.9.2 2015-11-02 18:31:45
Enter ".help" for usage hints.
sqlite> .tables
auth_group django_migrations
auth_group_permissions django_session
auth_permission django_site
auth_user products_category
auth_user_groups products_product
auth_user_user_permissions products_product_categories
django_admin_log products_variant
django_content_type
Contents of `migrations/0001_initial.py
class Migration(migrations.Migration):
initial = True
dependencies = [
]
operations = [
migrations.CreateModel(
name='Category',
fields=[
('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
('title', models.CharField(max_length=120, unique=True)),
('description', models.TextField(blank=True, null=True)),
],
),
migrations.CreateModel(
name='Product',
fields=[
('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
('name', models.CharField(max_length=120)),
('description', models.TextField(blank=True, null=True)),
('main_image', models.ImageField(upload_to=products.models.image_upload_location)),
('price', models.DecimalField(decimal_places=2, max_digits=20)),
('available', models.BooleanField(default=True)),
('categories', models.ManyToManyField(blank=True, to='products.Category')),
],
),
migrations.CreateModel(
name='Store',
fields=[
('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
('name', models.CharField(max_length=120)),
('description', models.TextField(blank=True, null=True)),
],
),
migrations.CreateModel(
name='Variant',
fields=[
('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
('variant_name', models.CharField(max_length=120)),
('description', models.TextField(blank=True, null=True)),
('variant_image', models.ImageField(null=True, upload_to=products.models.image_upload_location)),
('price', models.DecimalField(decimal_places=2, max_digits=20)),
('available', models.BooleanField(default=True)),
('product', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to='products.Product')),
('store', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to='products.Store')),
],
),
]
Answer: It seems as though the `store` table was dropped from the database and
migrations cannot figure out how to add it back. You could always recreate the
table in `dbshell`:
sqlite> .tables
auth_group django_migrations
auth_group_permissions django_session
auth_permission products_building
auth_user products_category
auth_user_groups products_product
auth_user_user_permissions products_product_categories
django_admin_log products_variant
django_content_type
sqlite> PRAGMA foreign_key s=OFF;
sqlite> BEGIN TRANSACTION;
sqlite> CREATE TABLE "products_store" ("id" integer NOT NULL PRIMARY KEY AUTOINCREMENT, "name" varchar(120) NOT NULL, "description" text NULL);
sqlite> COMMIT;
sqlite> .tables
auth_group django_migrations
auth_group_permissions django_session
auth_permission products_building
auth_user products_category
auth_user_groups products_product
auth_user_user_permissions products_product_categories
django_admin_log products_store
django_content_type products_variant
|
Alpine 3.3, Python 2.7.11, urllib2 causing SSL: CERTIFICATE_VERIFY_FAILED
Question: I have this small Dockerfile
FROM alpine:3.3
RUN apk --update add python
CMD ["python", "-c", "import urllib2; response = urllib2.urlopen('https://www.python.org')"]
Building it with `docker build -t alpine-py/01 .` and then running it with
`docker run -it --rm alpine-py/01` creates the following output
Traceback (most recent call last):
File "<string>", line 1, in <module>
File "/usr/lib/python2.7/urllib2.py", line 154, in urlopen
return opener.open(url, data, timeout)
File "/usr/lib/python2.7/urllib2.py", line 431, in open
response = self._open(req, data)
File "/usr/lib/python2.7/urllib2.py", line 449, in _open
'_open', req)
File "/usr/lib/python2.7/urllib2.py", line 409, in _call_chain
result = func(*args)
File "/usr/lib/python2.7/urllib2.py", line 1240, in https_open
context=self._context)
File "/usr/lib/python2.7/urllib2.py", line 1197, in do_open
raise URLError(err)
urllib2.URLError: <urlopen error [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:590)>
Yesterday I got bitten by the recent OpenSSL 1.0.2g release, which caused `py-
cryptograpy` to not compile. Luckily the guys from `py-cryptography` released
a new version on PyPI a couple of hours later. The issue was that a function
in OpenSSL got a new signature.
Could this be related or am I missing something?
Answer: You need to install ca-certificates to be able to validate signed certs by
public CAs:
FROM alpine:3.3
RUN apk --no-cache add python ca-certificates
CMD ["python", "-c", "import urllib2; response = urllib2.urlopen('https://www.python.org')"]
|
Problems using MySQL with AWS Lambda in Python
Question: I am trying to get up and running with AWS Lambda Python (beginner in Python
btw) but having some problems with including MySQL dependency. I am trying to
follow the instructions
[here](http://docs.aws.amazon.com/lambda/latest/dg/lambda-python-how-to-
create-deployment-package.html) on my Mac.
For step number 3, I am getting some problems with doing the command at the
root of my project
sudo pip install MySQL-python -t /
Error:
> Exception: Traceback (most recent call last): File
> "/Library/Python/2.7/site-packages/pip-1.5.6-py2.7.egg/pip/basecommand.py",
> line 122, in main status = self.run(options, args) File
> "/Library/Python/2.7/site-
> packages/pip-1.5.6-py2.7.egg/pip/commands/install.py", line 311, in run
> os.path.join(options.target_dir, item) File
> "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/shutil.py",
> line 292, in move raise Error, "Destination path '%s' already exists" %
> real_dst Error: Destination path '/MySQL_python-1.2.5-py2.7.egg-
> info/MySQL_python-1.2.5-py2.7.egg-info' already exists
I end up writing my following lambda function (works fine on my Mac), which
is:
import MySQLdb
def lambda_handler(event, context):
# Open database connection
db = MySQLdb.connect(...)
# prepare a cursor object using cursor() method
cursor = db.cursor()
sql = "SELECT * FROM Users"
try:
# Execute the SQL command
cursor.execute(sql)
# Fetch all the rows in a list of lists.
results = cursor.fetchall()
for row in results:
fname = row[0]
lname = row[1]
age = row[2]
sex = row[3]
income = row[4]
# Now print fetched result
print ("lname=%s" %(lname))
except:
print "Error: unable to fecth data"
# disconnect from server
db.close()
What I went on to do is go to /Library/Python/2.7/site-packages and copying
over the the MySQLdb folders/files that were downloaded when I did sudo pip
install MySQL-python (without -t /) (I'm sure I'm doing something wrong here),
to my lambda project, and then zipped the content along with the
lambda_function.py and uploaded to AWS Lambda.
Then I get:
> Unable to import module 'lambda_function': No module named MySQLdb
Grateful for any help and suggestions!
**EDIT**
Was able to do make sudo pip install MySQL-python -t /pathToProject work
(thanks for the help in the comments) but now I get this when runing the
lambda function:
> Unable to import module 'lambda_function': /var/task/_mysql.so: invalid ELF
> header
I know that if I work on a Linux box, then it should work fine (as suggested
by some people), but I am wondering if I can make it work from an OS X box.
Answer: For a use case like Lambda you'll be a lot happier using a pure python
implementation like [PyMySQL](https://github.com/PyMySQL/PyMySQL).
It's a drop in replacement for MySQLdb that follows the [Python Database
API](https://www.python.org/dev/peps/pep-0249/) specification. For most things
like triggered Lambda events it will be just as fast.
I've used it in production a lot and it works great.
|
Python script for performance testing of server
Question: I dont want to use any testing tool.. I am writing python script which hits
rest api to server... I want to hit 500/any_number_of hits of login/any api to
server at a same time so that I can check performance of server.
def login():
api = "http://0.0.0.0/api/method/login"
params = {"usr":"[email protected]","pwd":"password"}
reponse = requests.post(api,params=params)
def main():
for i in range(2):
for j in range(5):
t1 = Thread(target=login(), args=(j,))
t2 = Thread(target=get_profile(), args=(j,))
t1.start()
t2.start()
main()
will this code work ?? please suggest me how to do it...
Answer: Use a couroutine module like gevent or asyncio. You can have many coroutines,
but you will be limited in the number of threads. This limitation comes from
both the number of threads the OS will allow your process to have, and the
fact that threads incur a much greater performance hit (each thread needs its
own stack + cost of context switching).
Here's a way to do it with gevent:
from gevent import monkey monkey.patch_all()
import urllib2
from gevent.pool import Pool
def download(url):
return urllib2.urlopen(url).read()
if __name__ == '__main__':
urls = ['http://your_url'] * 100
pool = Pool(20)
print pool.map(download, urls)
|
Substract current time to -GMT in python
Question: I have a time which is 13:11:06 and i want to -GMT (i.e -0530). I can minus it
by simply doing -5 by splitting the string taking the first digit (convert to
int) and then minus it and then re-join. But then i get it in a format which
is 8:11:06 which is not right as it should be 08:11:06, secondly its a lengthy
process. Is there a easy way to get my time in -GMT format (08:11:06)
This is what i did to get -GMT time after getting the datetime
timesplithour = int(timesplit[1]) + -5
timesplitminute = timesplit[2]
timesplitseconds = timesplit[3]
print timesplithour
print timesplitminute
print timesplitseconds
print timesplithour + ":" + timesplitminute + ":" + timesplitseconds
Answer: You could use Python's
[`datatime`](https://docs.python.org/3.5/library/datetime.html?highlight=timedelta#module-
datetime) library to help you as follows:
import datetime
my_time = "13:11:06"
new_time = datetime.datetime.strptime("2016 " + my_time, "%Y %H:%M:%S") - datetime.timedelta(hours=5, minutes=30)
print new_time.strftime("%H:%M:%S")
This would print:
07:41:06
First it converts your string into a `datetime` object. It then creates a
`timedelta` object allowing you to subtract 5 hours 30 minutes from the
datetime object. Finally it uses `strftime` to format the resulting datetime
into a string in the same format.
|
Extracting datetime info from yeardatescalendar in python
Question:
import calendar
calendar.Calendar().yeardatescalendar(2014)
>>> [[[[datetime.date(2013, 12, 30), datetime.date(2013, 12, 31),...
The above code returns datetimes for calendar year 2014. However, it also
includes the last 2 days of 2013 and firs couple of days for 2015. Is there
any way I can just extract the 2014 info?
Answer: One way of doing it:
import datetime
def myFun(year):
res = []
d = datetime.datetime(year, 1, 1)
while d.year != year +1:
res.append(d)
d = d + datetime.timedelta(days=1)
return res
>>> myFun(2014)[:2]
[datetime.datetime(2014, 1, 1, 0, 0), datetime.datetime(2014, 1, 2, 0, 0)]
>>> len(myFun(2014))
365
|
How to run commands on same TCL shell using Python
Question: I am having all the libraries written in TCL. I want to create a GUI in Python
which will have few buttons and other options. In the start TCL shell will
open. When I will click the buttons, respective commands will be executed on
the TCL shell.
Is it possible to fire commands on the same shell of TCL without closing TCL
shell.
I searched google and find `Tkniter` module in Python but it will open TCL
shell everytime I need to execute command.
Answer: You can certainly use Tkinter to run a series of commands in the same Tcl
interpreter:
Python 2.7.9 (default, Feb 28 2016, 05:52:45) [C] on sunos5
Type "help", "copyright", "credits" or "license" for more information.
>>> import Tkinter
>>> root = Tkinter.Tk()
>>> root.tk.eval('set msg "hello world"')
'hello world'
>>> root.tk.eval('string length $msg')
'11'
>>> root.tk.eval('foreach x {1 2 4} {puts "$msg $x"}')
hello world 1
hello world 2
hello world 4
''
>>>
\- here the variable msg is set in one command and its value is used in later
commands, which would not work if we were creating a new interpreter for each
command. If you don't want the Tk window that gets created, just run
`root.tk.eval('wm withdraw .')` to hide it.
If this doesn't answer your question you had better explain what else it is
that you need :-)
|
Splitting Regex response column on python
Question: I am receiving an object array after applying `re.findall` for link and
hashtags on Tweets data. My data looks like
b=['https://t.co/1u0dkzq2dV', 'https://t.co/3XIZ0SN05Q']
['https://t.co/CJZWjaBfJU']
['https://t.co/4GMhoXhBQO', 'https://t.co/0V']
['https://t.co/Erutsftlnq']
['https://t.co/86VvLJEzvG', 'https://t.co/zCYv5WcFDS']
Now I want to split it in columns, I am using following
df = pd.DataFrame(b.str.split(',',1).tolist(),columns = ['flips','row'])
But it is not working because of weird datatype I guess, I tried few other
solutions as well. Nothing worked.And this is what I am expecting, two
separate columns
https://t.co/1u0dkzq2dV https://t.co/3XIZ0SN05Q
https://t.co/CJZWjaBfJU
https://t.co/4GMhoXhBQO https://t.co/0V
https://t.co/Erutsftlnq
https://t.co/86VvLJEzvG
Answer: It's not clear from your question what exactly is part of your data. (Does it
include the square brackets and single quotes?). In any case, the pandas
[`read_csv`](http://pandas.pydata.org/pandas-
docs/stable/generated/pandas.read_csv.html) function is very versitile and can
handle ragged data:
import StringIO
import pandas as pd
raw_data = """
['https://t.co/1u0dkzq2dV', 'https://t.co/3XIZ0SN05Q']
['https://t.co/CJZWjaBfJU']
['https://t.co/4GMhoXhBQO', 'https://t.co/0V']
['https://t.co/Erutsftlnq']
['https://t.co/86VvLJEzvG', 'https://t.co/zCYv5WcFDS']
"""
# You'll probably replace the StringIO part with the filename of your data.
df = pd.read_csv(StringIO.StringIO(raw_data), header=None, names=('flips','row'))
# Get rid of the square brackets and single quotes
for col in ('flips', 'row'):
df[col] = df[col].str.strip("[]'")
df
Output:
flips row
0 https://t.co/1u0dkzq2dV https://t.co/3XIZ0SN05Q
1 https://t.co/CJZWjaBfJU NaN
2 https://t.co/4GMhoXhBQO https://t.co/0V
3 https://t.co/Erutsftlnq NaN
4 https://t.co/86VvLJEzvG https://t.co/zCYv5WcFDS
|
Python: Open .doc file with antiword on windows
Question: I am trying to open a bunch of .doc files (not docx) in a folder using python.
I downloaded a modified "antiword" which was a precompiled execute file for
windows as the original antiword is only available for linux.
<http://www-stud.rbi.informatik.uni-frankfurt.de/~markus/antiword/>
After I downloaded it I insert it into my python27 folder and I run the
antiword.exe file.
honestly my problem is that I do not understand what is going on when I run
the execute. I had hoped that it would add a library to my python directory
and I could the import "antiword". Can anyone help me?
Thanks a lot.
BR Jonas
Answer: As I understand, antiword is not a python module that you can import. It's an
executable that can be run directly from the command prompt (cmd). I installed
antiword as explained in [00README.WIN document](http://www-
stud.rbi.informatik.uni-frankfurt.de/~markus/antiword/00README.WIN) and could
run it in cmd after adding its folder to PATH environment variable as well as
creating a HOME environment variable exactly as outlined in README. I could
successfully run the following example using testdoc.doc found in
antiword\Doc\
antiword -m cp852.txt filename.doc > filename.txt
I think if you need to do this in Python, you can run antiword similar to any
cmd command as previously
[explained](http://stackoverflow.com/questions/14894993/running-windows-shell-
commands-with-python). The same thing was previously
[suggested](http://stackoverflow.com/questions/125222/extracting-text-from-ms-
word-files-in-python). You could also give IronPython a try as previuosly
[recommended](http://ironpython.codeplex.com/).
I hope this helps!
|
How to split file into chunks by string delimiter in Python
Question: I'm gonna need to upload a potentially large csv file into my application.
Each section of that file is indicated by a `#TYPE *`. How should I go about
splitting it into chunks and doing further processing on each chunk? Each
chunk is a list of headers followed by all the values.
Right now I have written the processing for a single chunk but I'm not sure
how to do the operation for each chunk. I think that a regex operation would
be the best option because of the constant return of `#TYPE *`.
#TYPE Lorem.Text.A
...
#TYPE Lorem.Text.B
...
#TYPE Lorem.Text.C
...
**UPDATE**
This solution has been changed from saving all sections in one file to saving
all sections to separate files and zipping them into a zip file. This zip file
is read by python and further analyzed. If someone would be interested in that
explanation message me and I'll update this question.
Answer from @Padraic was the most helpful for the old course.
Answer: You could use a _groupby_ presuming the sections are delimited by lines
starting with `#TYPE`:
from itertools import groupby, chain
def get_sections(fle):
with open(fle) as f:
grps = groupby(f, key=lambda x: x.lstrip().startswith("#TYPE"))
for k, v in grps:
if k:
yield chain([next(v)], (next(grps)[1])) # all lines up to next #TYPE
You can get each section as you iterate:
In [13]: cat in.txt
#TYPE Lorem.Text.A
first
#TYPE Lorem.Text.B
second
#TYPE Lorem.Text.C
third
In [14]: for sec in get_sections("in.txt"):
....: print(list(sec))
....:
['#TYPE Lorem.Text.A\n', 'first\n']
['#TYPE Lorem.Text.B\n', 'second\n']
['#TYPE Lorem.Text.C\n', 'third\n']
If no other lines start with `#` then that alone will be enough to use in
startswith, there is nothing complicated in your pattern so it is not really a
use case for a regex. This also only stores a section at a time not the whole
file into memory.
If you have no leading whitespace and the only place `#` appears is before
TYPE it may be sufficient to just call groupby:
from itertools import groupby, chain
def get_sections(fle):
with open(fle) as f:
grps = groupby(f)
for k, v in grps:
if k:
yield chain([next(v)], (next(grps)[1])) # all lines up to next #TYPE
If there was some metadata at the start you could use dropwhile to skip lines
until we hit the `#Type` and then just group:
from itertools import groupby, chain, dropwhile
def get_sections(fle):
with open(fle) as f:
grps = groupby(dropwhile(lambda x: not x.startswith("#"), f))
for k, v in grps:
if k:
yield chain([next(v)], (next(grps)[1])) # all lines up to next #TYPE
Demo:
In [16]: cat in.txt
meta
more meta
#TYPE Lorem.Text.A
first
#TYPE Lorem.Text.B
second
second
#TYPE Lorem.Text.C
third
In [17]: for sec in get_sections("in.txt"):
print(list(sec))
....:
['#TYPE Lorem.Text.A\n', 'first\n']
['#TYPE Lorem.Text.B\n', 'second\n', 'second\n']
['#TYPE Lorem.Text.C\n', 'third\n']
|
Choosing and iterating specific sub-arrays in multidimensional arrays in Python
Question: This is a question that comes from the post here [Iterating and selecting a
specific array from a multidimensional array in
Python](http://stackoverflow.com/questions/35769536/iterating-and-selecting-a-
specific-array-from-a-multidimensional-array-in-python)
In that post, user @Cleb solved what it was my original problem: how to
perform a sum through columns in a 3d array:
import numpy as np
arra = np.arange(16).reshape(2, 2, 4)
which gives
array([[[0, 1, 2, 3],
[4, 5, 6, 7]],
[[8, 9, 10, 11],
[12, 13, 14, 15]]])
and the problem was how to perform the sum of columns in each matrix, i. e., 0
+ 4, 1 + 5, ... , 8 + 12, ..., 11 + 15. It was solved by @Cleb.
Then I wondered how to do it in the case of a sum of 0 + 8, 1 + 9, ..., 4 +
12, ..., 7 + 15, (odd and even columns) which was also solved by @Cleb.
But then I wondered if there are a general idea (which can be modified in each
specific case). Imagine you can add the first and the last rows and the center
rows, in columns, separately, i. e., 0 + 12, 1 + 13, ..., 3 + 15, 4 + 8, 5 +
9, ..., 7 + 11.
Is there a general way? Thank you.
Answer: Depending on the how exactly `arra` is defined, you can shift your values
appropriately using
[`np.roll`](http://docs.scipy.org/doc/numpy-1.10.1/reference/generated/numpy.roll.html):
arra_mod = np.roll(arra, arra.shape[2])
`arra_mod` then looks as follows:
array([[[12, 13, 14, 15],
[ 0, 1, 2, 3]],
[[ 4, 5, 6, 7],
[ 8, 9, 10, 11]]])
Now you can simply use the command from your [previous
question](http://stackoverflow.com/questions/35769536/iterating-and-selecting-
a-specific-array-from-a-multidimensional-array-in-python?lq=1) to get your
desired output:
map(sum, arra_mod)
which gives you the desired output:
[array([12, 14, 16, 18]), array([12, 14, 16, 18])]
You can also use a list comprehension
[sum(ai) for ai in arra_mod]
which gives you the same output.
If you prefer one-liner, you can therefore simply do:
map(sum, np.roll(arra, arra.shape[2]))
|
Accessing Flask wsgi structured app from interpreter
Question: I have a Flask app structured for deployment as wsgi. An issue I have is when
I want to load files from the Python interpreter.
The structure is:
|----api
|---------api
|--------------static
|--------------templates
|--------------venv
|--------------models.py
|--------------...
So that in the Python interpreter, when I load files in the directory
`api/api` I need to access them as `dir.filename`. For example, if I have a
file, `api/api/models.py`, I can load it by entering the command `from
api.mb_models import db`... however, this syntax chokes when I run the wsgi
app via a web server. I then get an error that the file does not exits:
`Traceback (most recent call last): File "api/extract.py", line 15, in
<module> import api.models as models ImportError: No module named api.models`
I also tried set the os variable as follows,
path = 'api'
os.chdir(path)
and while this works now as wsgi, I got the same error when trying to load
from the interpreter. The only way I can get this to currently run as wsgi is
without specifying the path in my import statements or using the os attribute,
which does not work when I load the files in the interpreter
The question is how to share the same configuration for deployment as a wsgi
app AND for running from the Python interpreter.
Note: I am using a virtual environment.
**EDIT**
I removed all references of `dir` in my file imports, so the wsgi app is
functioning as desired, then ran `os.cwd()` in the interpreter, which gave me
the expected result of `/Users/gms/development/python/api`. I then set the
working directory using `os.chdir('/Users/gms/development/python/api/api')`,
ran `os.cwd()` and got the desired result for the working directory, but I
still get a `ImportError: No module named extract` when I try loading it from
the interpreter.
Answer: I figured it out. I need to set these in the interpreter:
import sys
sys.path.append('working path here')
And, voila, everything works as desired.
|
Python: Finding unknown repeated word(s) in a list of strings
Question: I have a list of strings, which are subjects from different email
conversations. I would like to see if there are words or word combinations
which are being used frequently.
An example list would be:
subjects = [
'Proposal to cooperate - Company Name',
'Company Name Introduction',
'Into Other Firm / Company Name',
'Request for Proposal'
]
The function would have to detect that "Company Name" as combination is used
more than once, and that "Proposal" is being used more than once. These words
won't be known in advance though, so I guess it would have to start trying all
possible combinations.
The actual list is of course a lot longer than this example, so manually
trying all combinations doesn't seem like the best way to go. What would be
the best way to go about this?
**UPDATE**
I've used Tim Pietzcker's answer to start developing a function for this, but
I get stuck on applying the Counter correctly. It keeps returning the length
of the list as count for all phrases.
The phrases function, including punctuation filter and a check if this phrase
has already been checked, and a max length per phrase of 3 words:
def phrases(string, phrase_list):
words = string.split()
result = []
punctuation = '\'\"-_,.:;!? '
for number in range(len(words)):
for start in range(len(words)-number):
if number+1 <= 3:
phrase = " ".join(words[start:start+number+1])
if phrase in phrase_list:
pass
else:
phrase_list.append(phrase)
phrase = phrase.strip(punctuation).lower()
if phrase:
result.append(phrase)
return result, phrase_list
And then the loop through the list of subjects:
phrase_list = []
ranking = {}
for s in subjects:
result, phrase_list = phrases(s, phrase_list)
all_phrases = collections.Counter(phrase.lower() for s in subjects for phrase in result)
"all_phrases" returns a list with tuples where each count value is 167, which
is the length of the subject list I'm using. Not sure what I'm missing here...
Answer: You also want to find phrases that are composed of more than single words. No
problem. This should even scale quite well.
import collections
subjects = [
'Proposal to cooperate - Company Name',
'Company Name Introduction',
'Into Other Firm / Company Name',
'Request for Proposal',
'Some more Firm / Company Names'
]
def phrases(string):
words = string.split()
result = []
for number in range(len(words)):
for start in range(len(words)-number):
result.append(" ".join(words[start:start+number+1]))
return result
The function `phrases()` splits the input string on whitespace and returns all
possible substrings of any length:
In [2]: phrases("A Day in the Life")
Out[2]:
['A',
'Day',
'in',
'the',
'Life',
'A Day',
'Day in',
'in the',
'the Life',
'A Day in',
'Day in the',
'in the Life',
'A Day in the',
'Day in the Life',
'A Day in the Life']
Now you can count how many times each of these phrases are found in all your
subjects:
all_phrases = collections.Counter(phrase for subject in subjects for phrase in phrases(subject))
Result:
In [3]: print([(phrase, count) for phrase, count in all_phrases.items() if count > 1])
Out [3]:
[('Company', 4), ('Proposal', 2), ('Firm', 2), ('Name', 3), ('Company Name', 3),
('Firm /', 2), ('/', 2), ('/ Company', 2), ('Firm / Company', 2)]
Note that you might want to use other criteria than simply splitting on
whitespace, maybe ignore punctuation and case etc.
|
Python - OpenCV VideoCapture = False (Windows)
Question: I have a simple piece of code, written in Python (version 2.7.11) designed to
do things to a video file as follows:
import cv2
cap = cv2.VideoCapture('MyVideo.mov')
print(cap)
print(cap.isOpened())
while(cap.isOpened()):
#Do some stuff
The result of print(cap) is a 8 digit hex number, so I don't know if that
means that the video has been found.
However, the print statement for cap.isOpened() returns False. I have tried
several fixes, but none of them worked. Any help or insight would be very
helpful.
Things to note/things I have tried
* I am running Windows 8.1, Python 2.7.11 and OpenCV 3.1.0
* The location of the video file is in the same directory as the Python script
* I have the following directories appended to my PATH variable:
C:\Users\MyName\OpenCV3\opencv\build\x64\vc14\bin;
C:\Users\MyName\OpenCV3\opencv\sources\3rdparty\ffmpeg;
C:\Python27\;
C:\Python27\Scripts
* I have checked that I have opencv_ffmpeg.dll in the OpenCV vc14 bin directory
* I have checked that said dll file is titled opencv_ffmpeg310_64.dll
* I have tried redownloading said dll file, and renaming it to include the version of OpenCV and the fact that my system is a 64-bit one
* I have tried placing the dll file in the Python27 directory
* The code above works on Mac, but not on Windows (tried the code on 2 different Macs and it worked, tried it on 2 different Windows machines and it returned false both times)
Answer: Since your code shows no issues on Mac, try using other file extensions (eg.
mp4 or wmv) on your Windows system, for testing. If your video is loaded then,
that means OpenCV is correctly configured on your Windows, but apparently
there is no driver to play .mov files
|
Sorting Issue in Python
Question: I am attempting to sort a list which I have imported from a file in Python,
however I am having no luck, does anyone know what I am doing wrong?
fr = open("database_results\Class_" + option + ".txt", 'r')
lines = [line for line in fr if line.strip()]
fr.close()
lines.sort(key=int)
fw = open("database_results\Class_" + option + ".txt", 'w')
fw.writelines(lines)
print(lines)
print("ALERT: File successfully sorted numerically!")
The reason I am splitting the lines like this is because the data is stored
like this in the database:
[Name: 'John Smith' Score: '7']
[Name: 'Mitchel Jones' Score: '5']
I want the file to be sorted so the people who have received the highest score
are put to the top of the list. For the example above, this would be formatted
fine, because John has a higher score than Mitchel.
Answer: 1) You're using the key argument of sort wrong. Key specifies what part of
each item in your list is being used to sort. In my example, I'm supplying an
anonymous function which is saying that for each item in `l`, use the value at
index 0 for determining sort order
l = [
[3,1,2],
[1,5,2],
[0,9,3],
[2,5,2]
]
l.sort(key=lambda x : x[0])
print l # prints [[0, 9, 3], [1, 5, 2], [2, 5, 2], [3,1,2]]
2) In order to do your sort, you'll likely need to perform a split on each
line, identify which index the score is sitting in, and cast it to an int.
This should do the sort:
`lines.sort(reverse=True, key=lambda x : int(x.strip().split('Score:
')[1].replace(']', '').replace('"', "").replace("'", "")))`
Here's what's happening:
1. Split the string on score so we get back `["[Name: Blah Blah", "10]"]`
2. We grab the item from the new list where the score is sitting (index 1)
3. Replace the ], ', and " characters so we don't fail our int cast
4. Cast the score to an int for numeric sorting
3) Probably not the best idea to write from the same file you were just
reading from. It would be better to put it somewhere like
`"database_results\Class_{0}_sorted.txt".format(option)"`
|
Python and sqlite3 : insert matrix into table
Question: Let's say i have this matrix:
[[[u'artist1'], [u'song1']], [[u'artist2'], [u'song2']], [[u'artist3'], [u'song3']]]
I was wondering how can i insert it into a sql table so it will look like
this:
ID | ARTIST |SONG
-----------------
1 | artist1 | song1
2 | artist2 | song2
3 | artist3 | song3
I have about 1 million artists and 1 million songs i have to insert so it's
just an example :P
Thanks in advance!
Source code:
import sqlite3
import numpy as np
print('Opening SQL Database')
sql = sqlite3.connect('mblite_post.db')
cur = sql.cursor()
cursor=cur.execute("SELECT entity0 from r_artist_release LIMIT 500000000000000 ")
result_author = [row[0] for row in cur.fetchall()]
cursor=cur.execute("SELECT entity1 from r_artist_release LIMIT 500000000000000 ")
result_song = [row[0] for row in cur.fetchall()]
artistlist=[]
for x in result_author:
y=cur.execute("SELECT name FROM artist_name where id='%s'" % x)
artistname=[row[0] for row in cur.fetchall()]
artistlist.append(artistname)
songlist=[]
for y in result_song:
z=cur.execute("SELECT name FROM release_name where id='%s'" % y)
songname=[row[0] for row in cur.fetchall()]
songlist.append(songname)
matrix2 = [[artistlist[i], songlist[i]] for i in range(len(artistlist))]
print(len(matrix2))
sql2 = sqlite3.connect('itaidb.db')
cur2 = sql2.cursor()
cur2.execute('CREATE TABLE IF NOT EXISTS main (artist TEXT,song TEXT )')
for i, v in enumerate(matrix2):
cur2.execute('INSERT INTO main VALUES (?,?)', (v[0][0], v[1][0]))
sql2.commit()
#
#
# for ton in songlist:
# cur2.execute("UPDATE main SET (song) values (?) WHERE id='%r'", [''.join(ton)] % integer)
# sql2.commit()
# integer=integer+1
#
sql2.close()
sql.close()
# artistname=[]
# for x in author:
# y=cur.execute("SELECT name FROM artist_name where id='%s'" % x)
# artistname=artistname.append(list(y.fetchall()))
#
# print artistname
Answer: I suggest you create your list like this:
yourlist = [(artistlist[i], songlist[i]) for i, v in enumerate(artistlist)]
Then you can use a for loop to execute the `INSERT` statements:
for i, v in enumerate(yourlist, start=1):
cursor.execute('INSERT INTO yourtable VALUES (?,?,?)', (i, v[0], v[1]))
And don't forget to commit afterwards:
db.commit()
|
CX_Oracle - import data from Oracle to Pandas dataframe
Question: Hy,
I'm new in python and I want import some data from a Oracle Database to python
(pandas dataframe) using this simple query
SELECT*
FROM TRANSACTION
WHERE DIA_DAT >=to_date('15.02.28 00:00:00', 'YY.MM.DD HH24:MI:SS')
AND (locations <> 'PUERTO RICO'
OR locations <> 'JAPAN')
AND CITY='LONDON'
What I did
import cx_Oracle
ip = 'XX.XX.X.XXX'
port = YYYY
SID = 'DW'
dsn_tns = cx_Oracle.makedsn(ip, port, SID)
connection = cx_Oracle.connect('BA', 'PASSWORD', dsn_tns)
df_ora = pd.read_sql('SELECT* FROM TRANSACTION WHERE DIA_DAT>=to_date('15.02.28 00:00:00', 'YY.MM.DD HH24:MI:SS') AND (locations <> 'PUERTO RICO' OR locations <> 'JAPAN') AND CITY='LONDON'', con=connection)
But I have this error
SyntaxError: invalid syntax
What did I do wrong?
Thanks
Answer: You need to properly quote your SQL Query. If you look at the syntax
highlighting in your question (or an IDE), you'll notice that the single
quotes aren't working as you expect.
Change the outer most quotes to double quotes - if you want it all on one line
- or triple quotes if you want it across multiple lines:
query = """SELECT*
FROM TRANSACTION
WHERE DIA_DAT >=to_date('15.02.28 00:00:00', 'YY.MM.DD HH24:MI:SS')
AND (locations <> 'PUERTO RICO'
OR locations <> 'JAPAN')
AND CITY='LONDON'"""
df_ora = pd.read_sql(query, con=connection)
|
Faking a time stamp from time.time() in Nose
Question: I'm building a device object to poll data from connected devices in python and
I'm trying to test the inter workings of the object and all it's functions
using nose. I am running into a problem in general when writing a timestamp
using `time.time()` as each time the function is called the result the value
is different and this seriously screws up some test, for example this data
collection function:
def getData(self, data):
if type(data) is not type({}):
#print "Bad Type!"
raise TypeError
else:
#print "Good Type!"
self.outD = {}
datastr = ""
for key, value in data.iteritems():
self.outD[key] = value
self.outD["timestamp"] = time.time()
self.outD["id"] = self.id
self._writeCSV()
When I test the output of this function and compare the generated CSV file, it
always fails due to the time stamp. I can sub it out in my device object by
adding testing flags, but I was wondering if nose has a built in way to deal
with issues like this where the result of a function can be substituted with a
given value or a local function to fake the `time.time()` call. Is this
possible?
Answer: You can use
[`unittest.mock`](https://docs.python.org/dev/library/unittest.mock.html).
Example:
import time
from unittest import mock
@mock.patch('time.time', mock.MagicMock(return_value=12345))
def test_something():
assert time.time() == 12345
Produces the following output:
$ nosetests3 -v
test.test_something ... ok
----------------------------------------------------------------------
Ran 1 test in 0.006s
OK
Despite the fact that `mock` is part of the `unittest` package, it's actually
unrelated and works with any testing framework.
For Python < 3.3, you can use the [`mock` package from
PyPI](https://pypi.python.org/pypi/mock).
|
Best way to partially deep copy a dictionary in Python?
Question: I have a graph that is represented as a `dict` where each key is an instance
of a (self-defined) `Node` class and the values are sets of instances of
`Nodes`. So, basically, the graph looks something like this, but way larger:
`g = { Node1 : {Node2, Node3}, Node2 : {Node4}, Node3: set(), Node4 : {Node1}
}`
**In very short words of what I want to do:** I want to arbitrarily change a
dictionary and then revert it to its original value before those changes.
I have a series of transformations that I can make to this graph, but I don't
have any possible way of knowing beforehand which transformation that I want
to do. The transformation will always:
* Delete one key
* Add in two new vertices
* Change about 1/n edges
Since I don't know which transformation I want to do, I want to perform every
transformation to the same graph and then pick one.
An obvious idiom could be:
* Copy the dictionary to a temporary dictionary (`temp = g`)
* Repeat for each transformation `t`:
* Perform a transformation `t` on the graph `g` to form the graph `g'`
* Jot down information about the graph `g'` for later
* Set `g = temp` to restore the graph to the known-good state
This does not work because copying the dictionary only performs a shallow
copy, so all changes to `g` are also performed on `temp`.
I can use `deepcopy`, but even that cannot work as is. I want to `deepcopy`
the actual dictionary `g`, but the keys and elements in the values of `g` (the
`Nodes`) cannot be deepcopied, because in my transformation, I will look for
elements that are in `g` but not in `temp` because they are now new objects.
I can attempt to redefine `deepcopy` for the `Node` class, which _works_ , but
it is very hackish and I _do_ need to use deepcopy to perform my
transformations `t`.
Following is a minimal working example that does what I want it to do -- but
in a way that I _do not want to_ because then I need to create a workaround
for making deepcopy actually work when I need it to. Also, the code to do the
transformations is all using `g` and the actual `Nodes` in `g` as it stands
right now, so not having to change much of that would be nice.
Is there a better way to do this? (all `print`s should be `True`)
from copy import deepcopy
class MyClass:
def __init__(self, value):
self.value = value
def __repr__(self):
return str(self.value)
def __deepcopy__(self, memo):
# do not rly deep copy plx
return self
class1 = MyClass(1)
class2 = MyClass(2)
class3 = MyClass(3)
dict_class = { class1 : {class2, class3}, class2 : {class3}, class3 : {class1}}
#### Want to create a copy of the dictionary with exact same objects... ####
dict_class_copy = deepcopy(dict_class)
print(dict_class)
print(dict_class_copy)
print(class1 in dict_class and class2 in dict_class and class3 in dict_class)
print(class1 in dict_class_copy and class2 in dict_class_copy and class3 in dict_class_copy)
dict_class.pop(class2)
dict_class[class1].remove(class3)
# don't want to change original dictionary key values
print(class2 not in dict_class and class2 in dict_class_copy)
# this breaks w/o deepcopy!
print(class3 not in dict_class[class1] and class3 in dict_class_copy[class1])
# reassign it back
dict_class = dict_class_copy
# i want this back!
print(class2 in dict_class)
print(class3 in dict_class[class1])
Answer: Make a "1 level deep" copy of the dict by copying the keys and making copies
of the sets. Replace this:
dict_class_copy = deepcopy(dict_class)
with this:
dict_class_copy = {k:set(v) for k,v in dict_class.items()}
and your tests pass.
|
Click error "takes no arguments" in main()
Question: I am having issues which I believe are due to click. I am trying to run this
code and I keep running into the same traceback TypeError stating an argument
is being passed to main().
#!/usr/bin/python
# -*- coding: utf-8 -*-
import sys
import boto
import boto.ec2
import click
@click.command()
@click.option('--region', '-r', default='us-west-2', help='AWS Region')
def main():
try:
ec2 = boto.ec2.connect_to_region(region)
except Exception, error:
print("Boto Error: %s" ) % str(error)
else:
print("It's working!")
finally:
sys.exit(1)
if __name__ == "__main__":
main()
This code seems pretty simple, so I take click is doing something here to
prevent this for working correctly?
Traceback (most recent call last):
File "test.py", line 21, in <module>
main()
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/click-5.1-py2.7.egg/click/core.py", line 700, in __call__
return self.main(*args, **kwargs)
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/click-5.1-py2.7.egg/click/core.py", line 680, in main
rv = self.invoke(ctx)
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/click-5.1-py2.7.egg/click/core.py", line 873, in invoke
return ctx.invoke(self.callback, **ctx.params)
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/click-5.1-py2.7.egg/click/core.py", line 508, in invoke
return callback(*args, **kwargs)
TypeError: main() takes no arguments (1 given)
Answer: I'm not familiar with `click` module but from what I can see from the docs,
you should change `def main():` to `def main(region):` since you want the
function to accept the parameter you are passing from the command line.
|
Encrypting user input in Python with pyCrypto
Question: I am trying to do basic encryption in Python, in below program I encrypt
whatever user types in, and then I am displaying it back to the user after
decryption. I am using the pyCrypto library which I downloaded from here:
<http://www.voidspace.org.uk/python/modules.shtml#pycrypto>
Below is the code I have written so far:
from Crypto.Cipher import AES
AES_key = AES.new('This is a key')
#message = "The answer is no"
message = input("Enter text:")
ciphertext = AES_key.encrypt(message)
print (ciphertext)
decrypted_message = AES_key.decrypt(ciphertext)
print (decrypted_message)
The problem is when I taken input from the user, my code does not work, but
when I give static input the one which I have commented my code works fine.
Can anyone please help what should I do so that my accepts user input and
encrypts it?
Answer: `AES` is a block cipher algorithm so it requires you to have the text to be a
multiple of 16 bytes. your message `"The answer is no"` is of 16 bytes.But the
input wouldn't be so you can use the `MOD_CFB` of the `AES` to get around
this.
from Crypto.Cipher import AES
# Encryption
encryption_suite = AES.new('This is a key123', AES.MODE_CFB, 'This is an IV456')
cipher_text = encryption_suite.encrypt("A really secret message. Not for prying eyes.")
# Decryption
decryption_suite = AES.new('This is a key123', AES.MODE_CFB, 'This is an IV456')
plain_text = decryption_suite.decrypt(cipher_text)
this would work for user input.
For more info on `IV`(initialization vectors) go
[Here](http://www.cryptofails.com/post/70059609995/crypto-
noobs-1-initialization-vectors)
|
Get Common OS name of Linux Python
Question: I am trying to get Linux distro name like centos, fedora, ubuntu, SuSE etc in
python.
I made use of platform module.
My code is
import platform
version = platform.platform(aliased=0)
version = version.split('-with-',1)[1].split('-',1)[0]
print version
It gives me the desired output. But is there any simpler way other than this,
or any module which gives me the name directly?
Answer: Try this:
>>> import platform
>>> platform.linux_distribution()
('Red Hat Enterprise Linux Server', '6.6', 'Santiago')
|
logistic_sgd module, where to find it?
Question: doing a deep learning tutorial and my python cannot find that module.
from logistic_sgd import LogisticRegression, load_data
ImportError: No module named logistic_sgd
How can i install it ?
Answer: Download and Save logistic_sgd.py from the following link:
<http://deeplearning.net/tutorial/code/logistic_sgd.py>
Store it in the working directory. That's it!
|
How to sort a dictionary in Python?
Question: I would like to generate a report where my first column would contain the
duration of my SQL queries. That should be sorted by highest duration to the
lowest one.
Code:
import os
directory = "./"
results = {}
def isfloat(value):
try:
float(value)
return True
except ValueError:
pass
for root,dirs,files in os.walk(directory):
for file in files:
if file.endswith(".csv"):
input_file=open(file, 'r')
for line in input_file:
if line:
try:
duration=line.split(',')[13].split(' ')[1]
if isfloat(duration): # check if string is a float
results[duration]=line
except:
pass
output_file = open('report.csv', 'w')
for k,v in sorted(results.items()):
print k
output_file.write(k + ',' + v)
output_file.close()
output:
1266.114
1304.450
1360.771
1376.104
1514.518
500.105
519.432
522.594
522.835
528.622
529.664
I wonder why is the `sorted()` function sorting function is messing my results
?
Answer: Your keys are _strings_ , not numbers. They are sorted lexicographically.
Convert to a number first if you want numeric sorting:
for k,v in sorted(results.items(), key=lambda k_v: float(k_v[0])):
|
Using py_compile.compile() from within a Python script
Question: I am trying to understand [the
docs](https://docs.python.org/2/library/py_compile.html).
MY Python script generates Python code which will be run much later, so I want
to check now if what I generated is valid.
The docs say `py_compile.compile(file[, cfile[, dfile[, doraise]]])` and
> If doraise is true, a PyCompileError is raised when an error is encountered
> while compiling file.
So, I tried
source = open(generatedScriptPath, 'rt').read() + '\n'
try:
import py_compile
x = py_compile.compile(source, '', '', True)
except py_compile.PyCompileError, e:
print str(e)
but that inner Except is never hit, instead, an outer except catches
> Traceback (most recent call last): File
> "H:/code/testgen/testGen.py", line 293, in
> x = py_compile.compile(source, '', '', True) File
> "C:\Python27\lib\py_compile.py", line 106, in compile
> with open(file, 'U') as f: IOError: [Errno 2] No such file or directory: '#
> This script was auto-generated ...
How do I fix this? Note that I am open to alternatives, I just want the
simplest possible way to ask " is the code which I just generated
syntactically valid Python?"
Answer: Read the error message: "No such file or directory". The first argument is
supposed to be a file name to open. Or read the docs: "The source code is
loaded from the file name /file/." You might prefer the "compile" builtin,
which can compile a string of Python.
|
How to use Boost.Python
Question: I just recently discovered Boost.Python and I am trying to figure out how it
works. I tried to go through [the tutorial on the official
website](http://www.boost.org/doc/libs/1_60_0/libs/python/doc/html/tutorial/tutorial/hello.html).
However, I got
link.jam: No such file or directory
when running bjam as in the example (which appears to be just a warning), and
Traceback (most recent call last):
File "hello.py", line 7, in <module>
import hello_ext
ImportError: libboost_python.so.1.55.0: cannot open shared object file: No such file or directory
when running python hello.py.
I also tried to compile a module as described in [another
tutorial](http://www.shocksolution.com/python-basics-tutorials-and-
examples/linking-python-and-c-with-boostpython/) with similar results. I am
running Ubuntu14.04 with boost1.55 compiled myself.
* * *
I tried to compile the following:
#include <boost/python.hpp>
char const* greet()
{
return "hello, world";
}
BOOST_PYTHON_MODULE(hello_ext)
{
using namespace boost::python;
def("greet", greet);
}
with the following command from command line:
g++ -o hello_ext.so hello.cpp -I /usr/include/python2.7/ -I /home/berardo/boost_1_55_0/ -L /usr/lib/python2.7/ -L /home/berardo/boost/lib/ -lboost_python -lpython2.7 -Wl, -fPIC -expose-dynamic
which still gives me a:
/usr/bin/ld: impossibile trovare : File o directory non esistente
collect2: error: ld returned 1 exit status.
Answer: Finally, I was able to make it work. First, I fixed the linker issues, as
suggested by Dan. It finally compiled but I still got:
ImportError: libboost_python.so.1.55.0: cannot open shared object file: No such file or directory
The problem was that the python module was not able to load correctly so I
needed to add another linker option. Here, I report the final Makefile:
# location of the Python header file
PYTHON_VERSION = 2.7
PYTHON_INCLUDE = /usr/include/python$(PYTHON_VERSION)
# location of the Boost Python include files and library
BOOST_INC = ${HOME}/boost/include
BOOST_LIB = ${HOME}/boost/lib
# compile mesh classes
TARGET = hello_ext
$(TARGET).so: $(TARGET).o
g++ -shared -Wl,-rpath,$(BOOST_LIB) -Wl,--export-dynamic $(TARGET).o -L$(BOOST_LIB) -lboost_python -L/usr/lib/python$(PYTHON_VERSION)/config -lpython$(PYTHON_VERSION) -o $(TARGET).so
$(TARGET).o: $(TARGET).C
g++ -I$(PYTHON_INCLUDE) -I$(BOOST_INC) -fPIC -c $(TARGET).C
Notice the **-Wl,-rpath,** option, which apparently makes the new created
shared library available to the python script.
@Dan: Thanks for the valuable hints.
|
How to validate the syntax of a Python script?
Question: I just want the simplest possible way for my Python script to ask "is the
Python code which I just generated syntactically valid Python?"
I tried:
try:
import py_compile
x = py_compile.compile(generatedScriptPath, doraise=True)
pass
except py_compile.PyCompileError, e:
print str(e)
pass
But even with a file containing invalid Python, the exception is not thrown
and afterwards `x == None`.
Answer: There is no need to use
[`py_compile`](https://docs.python.org/3/library/py_compile.html). It's
intended use is to _write a bytecode file_ from the given source file. In fact
it will fail if you don't have the permissions to write in the directory, and
thus you could end up with some false negatives.
To just parse, and thus validate the syntax, you can use the
[`ast`](https://docs.python.org/2/library/ast.html) module to
[`parse`](https://docs.python.org/2/library/ast.html#ast.parse) the contents
of the file, or directly call the
[`compile`](https://docs.python.org/2/library/functions.html#compile) built-in
function.
import ast
def is_valid_python_file(fname):
with open(fname) as f:
contents = f.read()
try:
ast.parse(contents)
#or compile(contents, fname, 'exec', ast.PyCF_ONLY_AST)
return True
except SyntaxError:
return False
Be sure to _not_ execute the file, since if you cannot trust its contents (and
if you don't even know whether the file contains valid syntax I doubt you can
actually trust the contents even if you generated them) you could end up
executing malicious code.
|
Python will not print to a text file
Question: For some reason, the following code is unable to print to `Cache.txt`
import random
import time
text_file = open("Cache.txt", "w")
text_file.write("Numbers Used \n")
print("Welcome to the Bingo number generator")
UserNumber = str((random.randint(1,90)))
print(UserNumber)
text_file.write ("UserNumber")
text_file.close
Can someone help me figure out what is wrong with this code?
Answer: you need to call `close()` function like this:
text_file.close()
Plus, a more pythonic way would be to call `open()` with context manager
[with](https://docs.python.org/2/library/contextlib.html) :
with open("Cache.txt", "w") as text_file:
text_file.write("Numbers Used \n")
print("Welcome to the Bingo number generator")
UserNumber = str((random.randint(1,90)))
print(UserNumber)
text_file.write ("UserNumber")
No need to call `close()` doing that way
|
error using twilio.rest in python3
Question: I'm having an exception occur that I can't understand.
I'm using `twilio.rest` in python 3.4.2 and when I call the twilio api, I'm
receiving
> AttributeError: 'module' object has no attribute 'Http'
> (http2lib?)
I am using
from `twilio.rest import TwilioRestClient`
on the twilio website it shows that that should be the only import that I
need, but clearly something isn't working properly.
Answer: UPDATE: i finally fixed this. when i would install twilio, it would give the
message requirement already satisfied for httplib2, six, pytz, pysocks. i
uninstalled twilio, and uninstalled each of those packages, and then re
installed [Twilio](https://www.twilio.com/docs/python/install) (hoping it
would re-apply those packages)
it works now!! i can't really explain why, or perhaps there was a better
method, but I wanted to share.
|
Problems importing from python package (local vs on the python path)
Question: I am unable to get the following things to work simultaneously in Python2.7:
* import submodules from a local package
* import submodules from the package when it is on the PYTHONPATH
I have set up the sample directory structure as in the [python docs for
packages](https://docs.python.org/2/tutorial/modules.html#packages)
cd tmp
mkdir sound
mkdir sound/formats
mkdir sound/effects
mkdir sound/filters
cd sound
touch __init__.py
cp !$ formats/
cp __init__.py formats/
cp __init__.py effects/
cp __init__.py filters/
echo "def echofilter(): return(1) " > effects/echo.py
cd ../..
So, I end up with:
$ ls tmp/sound
effects/ filters/ formats/ __init__.py
If I make the package local, as it would be if it were acting as a git
submodule, for instance, ie by `cd tmp`, the following is successful:
$ python
Python 2.7.10 (default, Oct 14 2015, 16:09:02)
[GCC 5.2.1 20151010] on linux2
>>> from sound.effects import echo
>>>
Yet if I am located somewhere else (`cd ..`), and I put the package on my
PYTHONPATH, I cannot import as in the docs:
[~/tmp]$ cd ..
[~]$ python
Python 2.7.10 (default, Oct 14 2015, 16:09:02)
[GCC 5.2.1 20151010] on linux2
>>> import sys
>>> sys.path.append('/home/meuser/tmp/sound')
>>> from sound.effects import echo
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ImportError: No module named sound.effects
>>> sys.path.append('/home/meuser/tmp/sound/effects')
>>> from sound.effects import echo
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ImportError: No module named sound.effects
So how am I supposed to arrange things?
Answer: Ah! If it's a package, I need the folder _containing_ the package (ie ~/tmp/)
in my path, not the folder of the package itself (~/tmp/sound). Thus, the
following works:
>>> import sys
>>> sys.path.append('/home/meuser/tmp/')
>>> from sound.effects import echo
Now I believe this solves all my recent conundrums..
|
2D heat map using python and matplotlib
Question: I need to plot 2D "heat map" using python using data from my file. My file has
3 columns x,y, value. x goes from 1 to 199 and y from 1 to 49. I've managed to
use code from here: [Make a 2D pixel plot with
matplotlib](http://stackoverflow.com/questions/6323737/make-a-2d-pixel-plot-
with-matplotlib) but my area is rectangular and I need it to be "lying"
rectangle, but code above makes it "standing" rectangle.
Any way how to rotate it by 90 degrees anti-clockwise or transpose the data?
I'm very new to python and all the solutions I've found doesn't work...
Here's my code that produces "standing" rectangle:
import numpy as np
import matplotlib.pyplot as plt
import matplotlib.cm as cm
x,y,temp = np.loadtxt('snorm000990987662298').T
nrows, ncols = 199, 49
grid = temp.reshape((nrows, ncols))
plt.imshow(grid, cmap=cm.gist_gray)
plt.show()
Answer: Try using
[`numpy.transpose`](http://docs.scipy.org/doc/numpy-1.10.1/reference/generated/numpy.transpose.html):
grid = np.transpose(grid)
plt.imshow(grid, cmap=cm.gist_gray)
plt.show()
|
Python.net and DLLs
Question: I want to call a .Net dll using Python.net. Essentially what I want to do is
operate a hardware device that comes with some dlls and sample C# code for
operating it.
The sample of C# code I want to reimplement in python is:
string[] strDeviceKeys = null;
CmdLib8742 cmdLib = new CmdLib8742 (true, 5000, ref strDeviceKeys);
CmdLib8742 comes from a .net dll.
python.net _seems_ to be installed correctly.
I can do this in python:
import clr
clr.AddReference('CmdLib')
import NewFocus.Picomotor
cl = NewFocus.Picomotor.CmdLib8742()
That runs without error, but obviously doesn't seem to actually connect to the
device.
It seems like I need to convert the python types to types that are understood
by C#, so I probably have to replace `true` with `System.Boolean(True)`. But
it's not clear to me how I pass this `ref strDeviceKeys`. I'm guessing this is
passing a reference to the array of strings, but I don't know how to do that
in python. Any help would be appreciated.
Thanks.
Answer: You will probably need to look at [the `ctypes`
library](https://docs.python.org/3.5/library/ctypes.html), which allows
conversion between architecture-specific and Python values.
|
Python 2.7: applying str to collections.Counter and collections.defaultdict
Question: collections.Counter and collections.defaultdict are both inherited from dict.
So what is the difference between them which causes non-similar output
('class' and 'type')?
import collections
print str(collections.Counter)
print str(collections.defaultdict)
Output:
<class 'collections.Counter'>
<type 'collections.defaultdict'>
Answer: I'm afraid your answer here boils down to something rather boring: `Counter`
is written in Python and `defaultdict` is written in C.
Here's
[`collections.py`](https://svn.python.org/projects/python/trunk/Lib/collections.py).
Notice you can scroll down and find a standard class definition for `Counter`:
########################################################################
### Counter
########################################################################
class Counter(dict):
'''Dict subclass for counting hashable items. Sometimes called a bag
or multiset. Elements are stored as dictionary keys and their counts
are stored as dictionary values.
...
'''
However, `defaultdict` is imported from `_collections`:
from _collections import deque, defaultdict
As noted in [this answer](http://stackoverflow.com/a/18075267/2588818), that's
a built-in extension written in C.
You'll notice you get this same behavior if you string-ify `deque` (also C) or
some other class from `collections` written in Python:
>>> from collections import deque
>>> str(deque)
"<type 'collections.deque'>"
>>> from collections import OrderedDict
>>> str(OrderedDict)
"<class 'collections.OrderedDict'>"*
|
Passing a list to a function in order to move objects in tkinter (python 3)
Question: I am making a rubiks slide game. The first functioning button I am doing is
the clockwise button (every other button does nothing). i have the four
positions of squares set, and put them in a list called board. I then call the
list to the clockwise_move function from the clockwise button, and it is
supposed to move the square in whatever position stated. I cannot understand
why this will no work.
from tkinter import *
from tkinter import ttk
# --- Functions ---
def clockwise_move(square):
canvas.coords(square[0], 500, 2, 250, 250)
canvas.coords(square[1], 500, 490, 249, 250)
canvas.coords(square[2], 2, 2, 249, 249)
canvas.coords(square[3], 2, 490, 249, 250)
# --- Setup ---
main = Tk()
main.title("Rubik's Slide")
main.resizable(width=FALSE, height=FALSE)
main.geometry("700x550")
# --- Objects ---
frame = ttk.Frame(main)
button_frame = ttk.Frame(frame)
canvas = Canvas(frame, width=500, height=700)
#squares
square1 = canvas.create_rectangle(2, 2, 249, 249, fill="red")
square2 = canvas.create_rectangle(500, 2, 250, 250, fill="white")
square3 = canvas.create_rectangle(2, 490, 249, 250, fill="blue")
square4 = canvas.create_rectangle(500, 490, 250, 250, fill="black")
board = [square1,square2,square3,square4]
#buttons
clockwise = ttk.Button(button_frame, text="Clockwise", command=clockwise_move(board))
clockwise.grid(column=2, row=3)
counter_clockwise = ttk.Button(button_frame, text="Counterclock")
counter_clockwise.grid(column=3, row=3)
right = ttk.Button(button_frame, text="Right")
right.grid(column=2, row=1)
left = ttk.Button(button_frame, text="Left")
left.grid(column=2, row=2)
up = ttk.Button(button_frame, text="Up")
up.grid(column=3, row=1)
down = ttk.Button(button_frame, text="Down")
down.grid(column=3, row=2)
start = ttk.Button(button_frame, text="Start")
start.grid(column=2, row=4)
reset = ttk.Button(button_frame, text="Reset")
reset.grid(column=3, row=4)
#frame grid
frame.grid(column=1, row=1)
canvas.grid(column=1, row=1)
button_frame.grid(column=2, row=1)
#misc settings
for child in button_frame.winfo_children():
child.grid_configure(padx=10, pady=20)
main.mainloop() #end of GUI
Answer: In your line where you assign the command `clockwise_function` onto the
button, your are asigning the result of the function. So the outcome is, that
your function get called after you have started your app without clicking the
button.
The prove this you can simply put a print("Call") into your definition of
`clockwise_function`. Instead you can wrap the function call into a lambda
expression `command=lambda:clockwise_move(board))`. So instead of passing in
the result of the function you are passing in the instance of an anonymous
function.
An alternative would be removing the parameter `square` and using a global
variable.
Without an parameter you would simply:
def prototype():
print("do something")
... command = prototype # the reference to the function
the button click would then act like `command()`
Btw for making things easier you also could save your positions like in a
dictionary, list or Enum:
here I am using an dictionary
# Top Left | Top Right | Bottom Left | Bottom Right
p= {"tr":[500, 2, 250, 250],
"br":[500, 490, 249, 250],
"tl":[2, 2, 249, 249],
"bl":[2, 490, 249, 250]}
def clockwise_move(square):
canvas.coords(square[0], *p["tr"])
canvas.coords(square[1], *p["br"])
canvas.coords(square[2], *p["tl"])
canvas.coords(square[3], *p["bl"])
|
How to get all forms on webpage using python selenium?
Question: I searched for answer before ask here but didn't get lucky enough. So here it
goes, I am doing web scraping using python selenium. before choosing selenium
I checked for mechanize, scrapy but I failed to execute some button clicks
with them then I checked selenium it seems okay with some cons. I am saying
all this because if I chose the wrong tool then please correct me before it is
too late.
My question about selenium is how do I get all elements on webpage using
xpath. eg: On webpage each webpage I got 10 forms and each of them has a
button. So I want to get all the forms on web page to loop on them and click
button one by one.
eg:
<form id="#F0">
<input type="button" name="itens" value="Items" class="texField2" onClick="somefunction()"/>
</form>
<form id="#F0">
<input type="button" name="itens" value="Items" class="texField2" onClick="somefunction()"/>
</form>
<form id="#F1">
<input type="button" name="itens" value="Items" class="texField2" onClick="somefunction()"/>
</form>
<form id="#F2">
<input type="button" name="itens" value="Items" class="texField2" onClick="somefunction()"/>
</form>
<form id="#F3">
<input type="button" name="itens" value="Items" class="texField2" onClick="somefunction()"/>
</form>
<form id="#F4">
<input type="button" name="itens" value="Items" class="texField2" onClick="somefunction()"/>
</form>
Another thing, What I am doing is I click on button on 1st form (it takes me
to another page, I go back to history and click on 2nd button then go back to
history and so on) it seems scraping would be slow. Is there any better way to
do the same?
Thank you !!
Edit:
from selenium import webdriver
mydriver = webdriver.Firefox()
baseurl = """http://www.comprasnet.gov.br/consultalicitacoes/ConsLicitacao_Filtro.asp?numprp=&dt_publ_ini=24/02/2016&dt_publ_fim=10/03/2016&chkModalidade=1,2,3,20,5,99&chk_concor=31,32,41,42&chk_pregao=1,2,3,4&chk_rdc=1,2,3,4&optTpPesqMat=M&optTpPesqServ=S&chkTodos=-1&chk_concorTodos=-1&chk_pregaoTodos=-1&txtlstUf=&txtlstMunicipio=&txtlstUasg=&txtlstGrpMaterial=&txtlstClasMaterial=&txtlstMaterial=&txtlstGrpServico=&txtlstServico=&txtObjeto="""
mydriver.get(baseurl)
mydriver.find_element_by_id('ok').click()
buttons = mydriver.find_element_by_xpath("//form//input[@type='button']")
for button in buttons:
button.click()
Answer: You can get forms buttons by xpath with code below:
buttons = driver.find_elements_by_xpath(".//form//input[@type='button']")
And iterate them via simple for loop:
for button in buttons:
button.click()
Alternativelly you can use [find_elements_by_css_selector](http://selenium-
python.readthedocs.org/locating-elements.html#locating-elements) function to
get elements:
buttons = driver.find_elements_by_css_selector("input[type='button']")
|
Multiple Matrix Multiplications with Numpy
Question: I have about 650 csv-based matrices. I plan on loading each one using Numpy as
in the following example:
m1 = numpy.loadtext(open("matrix1.txt", "rb"), delimiter=",", skiprows=1)
There are matrix2.txt, matrix3.txt, ..., matrix650.txt files that I need to
process.
My end goal is to multiply each matrix by each other, meaning I don't
necessarily have to maintain 650 matrices but rather just 2 (1 ongoing and 1
that I am currently multiplying my ongoing by.)
Here is an example of what I mean with matrices defined from 1 to n: M1, M2,
M3, .., Mn.
M1*M2*M3*...*Mn
The dimensions on all the matrices are the same. **The matrices are not
square. There are 197 rows and 11 columns.** None of the matrices are sparse
and every cell comes into play.
What is the best/most efficient way to do this in python?
EDIT: I took what was suggested and got it to work by taking the transpose
since it isn't a square matrix. As an addendum to the question, i**s there a
way in Numpy to do element by element multiplication**?
Answer: A Python3 solution, if "each matrix by each other" actually means just
multiplying them in a row and _the matrices have compatible dimensions_ ( (n,
m) · (m, o) · (o, p) · ... ), which you hint at with "(1 ongoing and 1
that...)", then use (if available):
from functools import partial
fnames = map("matrix{}.txt".format, range(1, 651))
np.linalg.multi_dot(map(partial(np.loadtxt, delimiter=',', skiprows=1), fnames))
or:
from functools import reduce, partial
fnames = map("matrix{}.txt".format, range(1, 651))
matrices = map(partial(np.loadtxt, delimiter=',', skiprows=1), fnames)
res = reduce(np.dot, matrices)
Maps etc. are lazy in python3, so files are read as needed. Loadtxt doesn't
require a pre-opened file, a filename will do.
Doing all the combinations lazily, given that the matrices have the same shape
(will do a lot of rereading of data):
from functools import partial
from itertools import starmap, combinations
map_loadtxt = partial(map, partial(np.loadtxt, delimiter=',', skiprows=1))
fname_combs = combinations(map("matrix{}.txt".format, range(1, 651)), 2)
res = list(starmap(np.dot, map(map_loadtxt, fname_combs)))
Using a bit of grouping to reduce reloading of files:
from itertools import groupby, combinations, chain
from functools import partial
from operator import itemgetter
loader = partial(np.loadtxt, delimiter=',', skiprows=1)
fname_pairs = combinations(map("matrix{}.txt".format, range(1, 651)), 2)
groups = groupby(fname_pairs, itemgetter(0))
res = list(chain.from_iterable(
map(loader(k).dot, map(loader, map(itemgetter(1), g)))
for k, g in groups
))
Since the matrices are not square, but have the same dimensions, you would
have to add transposes before multiplication to match the dimensions. For
example either `loader(k).T.dot` or `map(np.transpose, map(loader, ...))`.
If on the other hand the question actually was meant to address element wise
multiplication, replace `np.dot` with `np.multiply`.
|
Django error: datetime.datetime
Question: When I execute `python manage.py migrate`, I get this error on the screen:
File "/usr/local/lib/python2.7/dist-packages/django/db/backends/base/schema.py", line 146, in column
sql
default_value = self.effective_default(field)
File "/usr/local/lib/python2.7/dist-packages/django/db/backends/base/schema.py", line 211, in effect
ive_default
default = field.get_db_prep_save(default, self.connection)
File "/usr/local/lib/python2.7/dist-packages/django/db/models/fields/__init_.py", line 710, in get_
db_prep_save
prepared=False)
File "/usr/local/lib/python2.7/dist-packages/django/db/models/fields/init.py", line 2003, in get
db_prep_value
value = self.get_prep_value(value)
File "/usr/local/lib/python2.7/dist-packages/django/db/models/fields/__init_.py", line 2010, in get
_prep_value
if value and ':' in value:
TypeError: argument of type 'datetime.datetime' is not iterable
I tried to execute `python manage.py syncdb` but the same error appears. What
could be the issue?
`Models.py` for more information:
from django.db import models
import datetime
from django.utils import timezone
class Machine(models.Model):
name = models.CharField(max_length=20, unique=True)
ins_date = models.DateField(default=timezone.now)
mod_date = models.DateField(default=timezone.now)
nagios_name = models.CharField(max_length=20)
dns = models.CharField(max_length=30)
ip_int = models.GenericIPAddressField(null=True, blank=True)
ip_ext = models.GenericIPAddressField()
vlan = models.IntegerField(null=True, blank=True)
custom = models.BooleanField(default=False)
def __str__(self):
return self.name
class SecurityGroup(models.Model):
name = models.CharField(max_length=20)
description = models.CharField(max_length=30, null=True, blank=True)
ins_date = models.DateField(default=timezone.now)
mod_date = models.DateField(default=timezone.now)
def __str__(self):
return self.name
class NACL(models.Model):
machine = models.ForeignKey(Machine)
securityGroup = models.ForeignKey(SecurityGroup)
ins_date = models.DateField(default=timezone.now)
mod_date = models.DateField(default=timezone.now)
BYADMIN_CHOICES = ((1, "Input"),(0, "Output"),)
class Rule(models.Model):
type_rule = models.CharField(max_length=10)
description = models.CharField(max_length=30, null=True, blank=True, default=None)
protocol = models.CharField(max_length=10)
port_range_min = models.IntegerField()
port_range_max = models.IntegerField(null=True, blank=True)
#sg_object = models.CharField(max_length=20, null=True, blank=True)
ip_object = models.GenericIPAddressField(null=True, blank=True)
securityGroup_object = models.ForeignKey(SecurityGroup, null=True, blank=True)
bound = models.BooleanField(choices=BYADMIN_CHOICES, default=1) #if bound == True: input else: output
class Meta:
unique_together = (("type_rule", "protocol", "port_range_min", "bound"))
def __str__(self):
return ("INPUT: " if(self.bound) else "OUTPUT: ") + self.type_rule + " " + self.protocol + " " + str(self.port_range_min) + " " + (str(self.securityGroup_object) if(self.securityGroup_object != None) else self.ip_object)
class Sg_rule(models.Model):
securityGroup = models.ForeignKey(SecurityGroup)
rule = models.ForeignKey(Rule)
ins_date = models.DateField(default=timezone.now)
mod_date = models.DateField(default=timezone.now)
class Service(models.Model):
name = models.CharField(max_length=20)
macroService = models.CharField(max_length=20)
def __str__(self):
return self.name
class M_Service(models.Model):
machine = models.ForeignKey(Machine)
service = models.ForeignKey(Service)
ins_date = models.DateField(default=timezone.now)
mod_date = models.DateField(default=timezone.now)
And the migration that is failing:
# -*- coding: utf-8 -*-
from __future__ import unicode_literals
from django.db import migrations, models
import datetime
from django.utils.timezone import utc
class Migration(migrations.Migration):
dependencies = [
('adminApp', '0009_auto_20160229_1716'),
]
operations = [
migrations.AddField(
model_name='rule',
name='ip_object',
field=models.GenericIPAddressField(default=datetime.datetime(2016, 2, 29, 17, 17, 42, 169176, tzinfo=utc)),
preserve_default=False,
),
migrations.AlterField(
model_name='rule',
name='sg_object',
field=models.CharField(max_length=20),
),
]
Answer: Your migration is trying to use a datetime as the default for an ip address
field. That doesn't make sense!
field=models.GenericIPAddressField(default=datetime.datetime(2016, 2, 29, 17, 17, 42, 169176, tzinfo=utc)),
|
python - web scraping BeautifulSoup and urllib
Question: I am using python 3.4 and my script looks like:
import urllib
from urllib.request import Request, urlopen
from urllib.error import URLError, HTTPError
from bs4 import BeautifulSoup
url = "http://www.embassy-worldwide.com/"
headers={'User-Agent': 'Mozilla/5.0'}
#req = Request(url, headers)
try:
req = urllib.request.Request(url, headers)
#print (req)
except HTTPError as e:
print('Error code: ', e.code)
except URLError as e:
print('Reason: ', e.reason)
else:
print('good!')
print (req)
#html = urllib.request.urlopen(req)
with urllib.request.urlopen(req) as response:
html = response.read()
print(html)
the code above results in an error:
**ValueError: Content-Length should be specified for iterable data of type
{'User-Agent': 'Mozilla/5.0'}**
How can I get the html code and then iterate the tags to get a list with all
countries?
Answer: Try this style in urllib3:
import sys
import re
import time
import pprint
import codecs
import unicodedata
import urllib3
import json
urllib3.disable_warnings()
cookie = '_session_id=29913b5f1b8836d2a8387ef4db00745e'
header = 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_2) AppleWebKit/536.26.17 (KHTML, like Gecko) Version/6.0.2 Safari/536.26.17'
url = 'https://yoururl.com/'
m = urllib3.PoolManager(num_pools = 15)
r = m.request('GET', url, None, {'User-Agent' : header, 'Cookie' : cookie})
print(r.data)
The imports are more than needed. It's just a snippet from a bigger part of a
scraper I use. And mine uses some regex because the tiny snippets I need are
in my case faster in regex than a full beautifulsoup implementation.
|
Attribute error : RPi.GPIO.PWM has no attribute 'ChangeDutyCycle'
Question: So i'm making a little robot using a raspberry pi B+ , everything is going
fairly nicely, but I get this error message that I don't seem to be able to
solve ..
Attribute error : RPi.GPIO.PWM has no attribute 'ChangeDutyCycle'
Here's two things you might need to know : :D \- The code worked perfectly
before I put it as a class, ChangeDutyCycle DOES exist \- If I put my mouse in
an 'unallowed' i.e. which gives ChangeDutyCycle a value less than 0 or more
than 100, the error changes and becomes 'ChangeDutyCycle can't accept value
less than 0 or more than 100' (So first you tell me there is no such function,
and then tell me it can't have some values? :roll: )
So I'm going slightly crazy now. Note : I'm a complete beginner in python, and
honestly, it seems to me like a bad version of java, but the RPi GPIO seems to
be optimised for this language so I'm trying it out, so if you see any other
mistake or bad things, do let me know :D
The code now :
My 'main', where I take input from a pygame window (position of mouse)
#!/usr/bin/python
# -*- coding: utf-8 -*-
import pygame
import RPi.GPIO as GPIO
from pygame.locals import *
from control import control
print('Path :', pygame.__file__)
def main():
pygame.init()
screen = pygame.display.set_mode((200,200))
ctrl = control()
bg = pygame.Surface(screen.get_size())
bg = bg.convert()
bg.fill((250,250,250))
font = pygame.font.Font(None, 36)
text = font.render("Hello", 1, (10,10,10,))
textpos = text.get_rect()
textpos.centerx = bg.get_rect().centerx
bg.blit(text, textpos)
screen.blit(bg, (0,0))
pygame.display.flip()
try:
while 1:
for event in pygame.event.get():
bg.fill((250, 250, 250))
if event.type == QUIT:
return
pos = pygame.mouse.get_pos()
x = pos[0]-100
y = -(pos[1]-200)-100
text = font.render(str(x)+' '+str(y), 1, (10,10,10,))
ctrl.updateEngine(x,y)
bg.blit(text,textpos)
screen.blit(bg, (0,0))
pygame.display.flip()
except KeyboardInterrupt:
return
finally:
ctrl.cleanup()
if __name__ == '__main__': main()
And my class with functions to control motors , control.py :
import RPi.GPIO as GPIO
from time import sleep
import sys
import Tkinter as tk
class control:
def __init__(self):
import RPi.GPIO as GPIO
GPIO.setmode(GPIO.BCM)
GPIO.setup(3, GPIO.OUT)# set GPIO 25 as output for white led
GPIO.setup(18, GPIO.OUT)# set GPIO 24 as output for red led
GPIO.setup(2, GPIO.OUT)
GPIO.setup(17, GPIO.OUT)
self.Rb = GPIO.PWM(2, 100)
self.Lf = GPIO.PWM(18, 100)
self.Lb = GPIO.PWM(17, 100)
self.Rf = GPIO.PWM(3, 100)
self.Rb.start(0)
self.Rf.start(0)
self.Lb.start(0)
self.Lf.start(0)
def cleanup(self):
self.Rb.stop()
self.Rf.stop()
self.Lb.stop()
self.Lf.stop()
def updateEngine(self, x, y):
self.clear()
if y>15 and (x>15 or x<-15) :
self.Rf.ChangeDutyCucle(y-15-x)
self.Lf.ChangeDutyCycle(y-15+x)
elif y<-15 and (x>15 or x<-15) :
self.Rb.ChangeDutyCycle(-15-y-x)
self.Lb.ChangeDutyCycle(-15-y+x)
def clear(self):
self.Rf.ChangeDutyCycle(0)
self.Rb.ChangeDutyCycle(0)
self.Lf.ChangeDutyCycle(0)
self.Lb.ChangeDutyCycle(0)
So the error happens in control.py, at the updateEngine method. Also you'll
note I imported an amazing number of 3 times the same package (RPi.GPIO) cause
I'm not sure where to import it ! :)
Any help would be graciously accepted :)
Answer: I tracked down my issue to a typo: My `updateEngine` function had a call to
`self.Rf.ChangeDutyCucle`, when it should have been `self.Rf.ChangeDutyCycle`.
|
Unicode error ascii can't encode character
Question: I am trying to import a csv file in order to train my classifier but I keep
receiving this error
traceback (most recent call last):
File "updateClassif.py", line 17, in <module>
myClassif = NaiveBayesClassifier(fp, format="csv")
File "C:\Python27\lib\site-packages\textblob\classifiers.py", line 191, in __init__
super(NLTKClassifier, self).__init__(train_set, feature_extractor, format, **kwargs)
File "C:\Python27\lib\site-packages\textblob\classifiers.py", line 123, in __init__
self.train_set = self._read_data(train_set, format)
File "C:\Python27\lib\site-packages\textblob\classifiers.py", line 143, in _read_data
return format_class(dataset, **self.format_kwargs).to_iterable()
File "C:\Python27\lib\site-packages\textblob\formats.py", line 68, in __init__
self.data = [row for row in reader]
File "C:\Python27\lib\site-packages\textblob\unicodecsv\__init__.py", line 106, in next
row = self.reader.next()
UnicodeEncodeError: 'ascii' codec can't encode character u'\xe6' in position 55: ordinal not in range(128)
The CSV file contains 1600000 lines of tweets so I believe some tweets contain
special characters. I have tried saving it using open office as someone
recommended but still the same result. I also tried using latin encoding but
the same result. This is my code :
with codecs.open('tr.csv', 'r' ,encoding='latin-1') as fp:
myClassif = NaiveBayesClassifier(fp, format="csv")
This is the code from the library I am using:
def __init__(self, csvfile, fieldnames=None, restkey=None, restval=None,
dialect='excel', encoding='utf-8', errors='strict', *args,
**kwds):
if fieldnames is not None:
fieldnames = _stringify_list(fieldnames, encoding)
csv.DictReader.__init__(self, csvfile, fieldnames, restkey, restval, dialect, *args, **kwds)
self.reader = UnicodeReader(csvfile, dialect, encoding=encoding,
errors=errors, *args, **kwds)
if fieldnames is None and not hasattr(csv.DictReader, 'fieldnames'):
# Python 2.5 fieldnames workaround. (http://bugs.python.org/issue3436)
reader = UnicodeReader(csvfile, dialect, encoding=encoding, *args, **kwds)
self.fieldnames = _stringify_list(reader.next(), reader.encoding)
self.unicode_fieldnames = [_unicodify(f, encoding) for f in
self.fieldnames]
self.unicode_restkey = _unicodify(restkey, encoding)
def next(self):
row = csv.DictReader.next(self)
result = dict((uni_key, row[str_key]) for (str_key, uni_key) in
izip(self.fieldnames, self.unicode_fieldnames))
rest = row.get(self.restkey)
Answer: Note that the traceback says _En_ codeError, not DecodeError. It looks like
the NaiveBayesClassifier is expecting ascii. Either make it accept Unicode,
or, if this is OK for your application, replace non-ascii characters with '?'
or something.
|
Cookies and render for an angular js app using Phantomjs and python
Question: I have an object that can call a web page fine, even with `add_cookie`.
However, I want to render a site that is making heavy use of angularjs. For
some reason I seem to be unable to set the correct cookies, which I have
pulled from a live session. So I am uncertain how much of this is cookie-foo
that I'm getting wrong, and how much is angular-js-foo that needs to happen
that I'm missing. If people have input here that would be great, but even
comments pointing me to where to go ingest would be helpful because I'm not
getting far on my own. I've scrubbed the values following. Even some pointers
on how to debug this. My goal is to render the `div`s on the page.
from selenium import webdriver
from selenium.webdriver.common.desired_capabilities import DesiredCapabilities
from bs4 import BeautifulSoup
class WebPage():
def __init__(self):
dcap = dict(DesiredCapabilities.PHANTOMJS)
dcap["phantomjs.page.settings.userAgent"] = (
"Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/53 "
"(KHTML, like Gecko) Chrome/15.0.87"
)
self.driver = webdriver.PhantomJS(desired_capabilities=dcap, service_args=['--ignore-ssl-errors=true', '--ssl-protocol=any'])
self.driver.set_window_size(1024, 768)
def get_page(self):
url = "http://proadvisor.intuit.com/search/index-standalone.html?v2#/search-result?location=60613&distance=500"
self.driver.get(url)
cookie = {'aam_aud': 'a_value', 'ttax': 0}
self.driver.add_cookie(cookie)
page = BeautifulSoup(self.driver.page_source, "lxml")
page.find_all("div")
if __name__ == '__main__':
wp = WebPage()
wp.get_page()
and just now getting:
> selenium.common.exceptions.WebDriverException: Message: Error Message =>
> 'Can only set Cookies for the current domain' caused by Request =>
> {"headers":{"Accept":"application/json","Accept-
> Encoding":"identity","Connection":"close","Content-Length":"104","Content-
> Type":"application/json;charset=UTF-8","Host":"127.0.0.1:34940","User-
> Agent":"Python-
> urllib/3.3"},"httpVersion":"1.1","method":"POST","post":"{\"cookie\":
> {\"aam_aud\": \"a_value\", \"ttax\": 0}, \"sessionId\":
> \"A-hash\"}","url":"/cookie","urlParsed":{"anchor":"","query":"","file":"cookie","directory":"/","path":"/cookie","relative":"/cookie","port":"","host":"","password":"","user":"","userInfo":"","authority":"","protocol":"","source":"/cookie","queryKey":{},"chunks":["cookie"]},"urlOriginal":"/session/a_hash/cookie"}
Answer: You have to add domain to your cookie.
Try something like this:
cookie = {'aam_aud': 'a_value', 'ttax': 0, 'domain' : http://proadvisor.intuit.com}
You might have to play with it a bit for your base URL, but I think that
should work. You have to tell the cookie on what websites you want to use that
cookie on.
|
normalizing JSON datestrings to UTC python
Question: I have an important test that says "Calculate users that logged in during the
month of April normalized to the UTC timezone."
Items look as such:
[ {u'email': u' [email protected]',
u'login_date': u'2014-05-08T22:30:57-04:00'},
{u'email': u'[email protected]',
u'login_date': u'2014-04-25T13:27:48-08:00'},
]
It seems to me that an item like `2014-04-13T17:12:20-04:00` means "April
13th, 2014, at 5:12:20 pm, 4 hours behind UTC". Then I just use strptime to
convert to datetime ([Converting JSON date string to python
datetime](http://stackoverflow.com/questions/10805589/converting-json-date-
string-to-python-datetime)), and subtract a timedelta of however many hours I
get from a regex that grabs the end of string? I feel this way because some
have a + at the end instead of -, like `2014-05-07T00:30:06+07:00`
Thank you
Answer: It is probably best to use the
[`dateutil.parser.parse`](https://pypi.python.org/pypi/python-dateutil/2.5.0)
and [`pytz`](https://pypi.python.org/pypi/pytz) packages for this purpose.
This will allow you to parse a string and convert it to a datetime object with
UTC timezone:
>>> s = '2014-05-08T22:30:57-04:00'
>>> import dateutil.parser
>>> import pytz
>>> pytz.UTC.normalize(dateutil.parser.parse(s))
datetime.datetime(2014, 5, 9, 2, 30, 57, tzinfo=<UTC>)
|
Concatenate audio files [Python 2.7]
Question: **Is** there any way to concatenate or merge two audio files into one?
**Requirements** : Must use built-in modules only [may use PyGame]
**Audio File format** : .wma OR .wav OR .mp3
I have looked at many questions now and found solutions that involved
downloading modules (which I do not prefer).
Any help would be welcome.
Answer: I make some research and found this.
#import libraries
from glob import iglob
import shutil
import os
#create path variable
PATH = r'C:\music'
#create everything.mp3
destination = open('everything.mp3', 'wb')
for filename in iglob(os.path.join(PATH, '*.mp3')):
shutil.copyfileobj(open(filename, 'rb'), destination)
#make them all together with for
destination.close()
#close file
from [here](http://stackoverflow.com/questions/1001538/how-do-i-concatenate-
files-in-python).
|
Reading Twitter JSON result
Question: What is the correct way to read these twitter search results?
{u'contributors': None, u'truncated': False, u'text': u"Google's deep learning project can figure out where any photo was taken, without geotags https://t.co/8URtvHUgjx https://t.co/hTQobCpA4U", u'is_quote_status': False, u'in_reply_to_status_id': None, u'id': 703129624285286400, u'favorite_count': 198, u'source': u'<a href="http://sproutsocial.com" rel="nofollow">Sprout Social</a>', u'retweeted': False, u'coordinates': None, u'entities': {u'symbols': [], u'user_mentions': [], u'hashtags': [], u'urls': [{u'url': u'https://t.co/8URtvHUgjx', u'indices': [89, 112], u'expanded_url': u'http://www.theverge.com/2016/2/25/11112594/google-new-deep-learning-image-location-planet?utm_campaign=theverge&utm_content=chorus&utm_medium=social&utm_source=twitter', u'display_url': u'theverge.com/2016/2/25/1111\u2026'}], u'media': [{u'source_user_id': 275686563, u'source_status_id_str': u'702916863450345474', u'expanded_url': u'http://twitter.com/verge/status/702916863450345474/photo/1', u'display_url': u'pic.twitter.com/hTQobCpA4U', u'url': u'https://t.co/hTQobCpA4U', u'media_url_https': u'https://pbs.twimg.com/media/CcFDKaHWEAEyUOR.jpg', u'source_user_id_str': u'275686563', u'source_status_id': 702916863450345474, u'id_str': u'702916862934388737', u'sizes': {u'small': {u'h': 383, u'resize': u'fit', u'w': 680}, u'large': {u'h': 675, u'resize': u'fit', u'w': 1200}, u'medium': {u'h': 675, u'resize': u'fit', u'w': 1200}, u'thumb': {u'h': 150, u'resize': u'crop', u'w': 150}}, u'indices': [113, 136], u'type': u'photo', u'id': 702916862934388737, u'media_url': u'http://pbs.twimg.com/media/CcFDKaHWEAEyUOR.jpg'}]}, u'in_reply_to_screen_name': None, u'in_reply_to_user_id': None, u'retweet_count': 232, u'id_str': u'703129624285286400', u'favorited': False, u'user': {u'follow_request_sent': False, u'has_extended_profile': False, u'profile_use_background_image': True, u'default_profile_image': False, u'id': 275686563, u'profile_background_image_url_https': u'https://pbs.twimg.com/profile_background_images/481546505468145664/a59ZFvIP.jpeg', u'verified': True, u'profile_text_color': u'333333', u'profile_image_url_https': u'https://pbs.twimg.com/profile_images/615501837341466624/I4jVBBp-_normal.jpg', u'profile_sidebar_fill_color': u'EFEFEF', u'entities': {u'url': {u'urls': [{u'url': u'http://t.co/W2SFxIXkC4', u'indices': [0, 22], u'expanded_url': u'http://www.theverge.com', u'display_url': u'theverge.com'}]}, u'description': {u'urls': [{u'url': u'https://t.co/W2SFxIXkC4', u'indices': [0, 23], u'expanded_url': u'http://www.theverge.com', u'display_url': u'theverge.com'}]}}, u'followers_count': 1180845, u'profile_sidebar_border_color': u'000000', u'id_str': u'275686563', u'profile_background_color': u'FFFFFF', u'listed_count': 29266, u'is_translation_enabled': True, u'utc_offset': -18000, u'statuses_count': 88374, u'description': u'https://t.co/W2SFxIXkC4 covers the future of technology, science, art, and culture. Snapchat: verge', u'friends_count': 139, u'location': u'New York', u'profile_link_color': u'FA4D2A', u'profile_image_url': u'http://pbs.twimg.com/profile_images/615501837341466624/I4jVBBp-_normal.jpg', u'following': False, u'geo_enabled': True, u'profile_banner_url': u'https://pbs.twimg.com/profile_banners/275686563/1433249898', u'profile_background_image_url': u'http://pbs.twimg.com/profile_background_images/481546505468145664/a59ZFvIP.jpeg', u'screen_name': u'verge', u'lang': u'en', u'profile_background_tile': False, u'favourites_count': 1217, u'name': u'The Verge', u'notifications': False, u'url': u'http://t.co/W2SFxIXkC4', u'created_at': u'Fri Apr 01 19:54:22 +0000 2011', u'contributors_enabled': False, u'time_zone': u'Eastern Time (US & Canada)', u'protected': False, u'default_profile': False, u'is_translator': False}, u'geo': None, u'in_reply_to_user_id_str': None, u'possibly_sensitive': False, u'lang': u'en', u'created_at': u'Fri Feb 26 08:09:00 +0000 2016', u'in_reply_to_status_id_str': None, u'place': None, u'metadata': {u'iso_language_code': u'en', u'result_type': u'popular'}}
I tried the following code but it always throws errors:
with open('../data/full_results.txt', 'r') as fh:
for tweet in fh:
print(tweet['text'])
> TypeError: string indices must be integers, not str
while trying the below code, I get ValueError:
with open('../data/full_results.txt', 'r') as fh:
for line in fh:
tweet = json.loads(line)
print(tweet['text'])
> ValueError: Expecting property name: line 1 column 2 (char 1)
But when I assign the same twitter response line to a variable in `Ipython`,
In [2]: tweet = {u'contributors': None, ... u'result_type': u'popular'}}
In [3]: tweet[text]
Out [3]: u"Google's deep learning ...."
It gives correct result. But I can't understand why?
Answer: `tweet` is a line read from the file, not a dictionary. And, it looks like
each line is not a valid JSON string, but looks like a string representation
of a dictionary. First thing to check/fix is how these tweets were dumped into
this file in this format in the first place. You need to use
[`json.dump()`](https://docs.python.org/2/library/json.html#json.dump) or
[`json.dumps()`](https://docs.python.org/2/library/json.html#json.dumps) to
have a proper JSON in the output file. Then, to read the tweets, if you have a
tweet per line, the following should work:
import json
with open('../data/full_results.txt', 'r') as fh:
for line in fh:
tweet = json.loads(line)
print(tweet['text'])
If you have a _list of tweets_ dumped to JSON:
import json
with open('../data/full_results.txt', 'r') as fh:
tweets = json.load(fh)
for tweet in tweets:
print(tweet['text'])
If you cannot change the way tweets were dumped into the file, you might load
the tweets with
[`ast.literal_eval()`](https://docs.python.org/2/library/ast.html#ast.literal_eval):
from ast import literal_eval
with open('../data/full_results.txt', 'r') as fh:
for line in fh:
tweet = literal_eval(line)
print(tweet['text'])
|
How to remove first few characters from every 1st line of each json file
Question: I am relatively new to python. I am trying to merge all JSON files into a one
single JSON file from a folder. I could do my merge. However I would like to
remove the some characters of the 1st line in every file to make the entire
JSON valid.
# Script to combine all jsons but need to remove the closing , at the end
import glob
import re
# read the whole folder
read_files = glob.glob("bus_stop_1012/*.json")
with open("bus_stop_1012/bus_arrival_1012.json", "wb") as outfile:
# this is the beginning of the combined file
outfile.write(' ')
for f in read_files:
# will append each data file
with open(f, "rb") as infile:
outfile.write(infile.read())
# will have to add , at the end of each element
outfile.write(',')
# move back 1 character to remove the last , and end the file
outfile.seek(-1,1)
outfile.write(']}')
which generates this single JSON file from a example of 2 json files:
{"data": [{"time": "2016-03-02 17:45:20 SGT+0800", "result":{
"BusStopID": "1012",
"Services": [
{
"NextBus": {
"EstimatedArrival": "2016-03-02T17:48:21+08:00",
"Feature": "WAB",
"Latitude": "1.2871405",
"Load": "Seats Available",
"Longitude": "103.8456715",
"VisitNumber": "1"
},
"Operator": "SBST",
"OriginatingID": "10589",
"ServiceNo": "12",
"Status": "In Operation",
"SubsequentBus": {
"EstimatedArrival": "2016-03-02T17:56:02+08:00",
"Feature": "WAB",
"Latitude": "0",
"Load": "Seats Available",
"Longitude": "0",
"VisitNumber": "1"
},
"SubsequentBus3": {
"EstimatedArrival": "2016-03-02T18:06:02+08:00",
"Feature": "WAB",
"Latitude": "0",
"Load": "Seats Available",
"Longitude": "0",
"VisitNumber": "1"
},
"TerminatingID": "77009"
}
],
"odata.metadata":
"http://datamall2.mytransport.sg/ltaodataservice/$metadata#BusArrival/@Element"
}},{"data": [{"time": "2016-03-02 17:49:36 SGT+0800", "result":{
"BusStopID": "1012",
"Services": [
{
"NextBus": {
"EstimatedArrival": "2016-03-02T17:48:47+08:00",
"Feature": "WAB",
"Latitude": "1.2944553333333333",
"Load": "Seats Available",
"Longitude": "103.85045283333334",
"VisitNumber": "1"
},
"Operator": "SBST",
"OriginatingID": "10589",
"ServiceNo": "12",
"Status": "In Operation",
"SubsequentBus": {
"EstimatedArrival": "2016-03-02T17:58:26+08:00",
"Feature": "WAB",
"Latitude": "1.2821243333333334",
"Load": "Seats Available",
"Longitude": "103.841401",
"VisitNumber": "1"
},
"SubsequentBus3": {
"EstimatedArrival": "2016-03-02T18:06:02+08:00",
"Feature": "WAB",
"Latitude": "0",
"Load": "Seats Available",
"Longitude": "0",
"VisitNumber": "1"
},
"TerminatingID": "77009"
}
],
"odata.metadata": "http://datamall2.mytransport.sg/ltaodataservice/$metadata#BusArrival/@Element"
}}]}
I would need the **{"data": [** of each subsequent JSON file to be removed as
it is found in every JSON file.
Answer: You could decode from JSON, extract the elements you want, then write those
out as JSON again.
If the goal is to produce one large `{"data": [....]}` list, you can get away
with writing each element in the list separately if you take care not to write
a last comma:
import glob
import json
# read the whole folder
read_files = glob.glob("bus_stop_1012/*.json")
with open("bus_stop_1012/bus_arrival_1012.json", "wb") as outfile:
# this is the beginning of the combined file
outfile.write('{"data": [\n')
sep = ''
for f in read_files:
# will append each data file
with open(f) as infile:
try:
for obj in json.load(infile)['data']:
outfile.write(sep)
json.dump(obj, outfile)
sep = ','
except ValueError:
print 'Failed to load {}'.format(f)
outfile.write(']}')
|
python read csv file with row and column headers into dictionary with two keys
Question: I have csv file of the following format,
,col1,col2,col3
row1,23,42,77
row2,25,39,87
row3,48,67,53
row4,14,48,66
I need to read this into a dictionary of two keys such that
dict1['row1']['col2'] = 42
dict1['row4']['col3'] = 66
If I try to use
[csv.DictReader](https://docs.python.org/3/library/csv.html#csv.DictReader)
with default options
with open(filePath, "rb" ) as theFile:
reader = csv.DictReader(theFile, delimiter=',')
for line in reader:
print line
I get the following output
{'': 'row1', 'col2': '42', 'col3': '77', 'col1': '23'}
{'': 'row2', 'col2': '39', 'col3': '87', 'col1': '25'}
{'': 'row3', 'col2': '67', 'col3': '53', 'col1': '48'}
{'': 'row4', 'col2': '48', 'col3': '66', 'col1': '14'}
I'm not sure of how to process this output to create the type of dictionary
that I'm interested in.
For sake of completeness, it would also help if you can address how to write
back the dictionary into a csv file with the above format
Answer: Using the CSV module:
import csv
dict1 = {}
with open("test.csv", "rb") as infile:
reader = csv.reader(infile)
headers = next(reader)[1:]
for row in reader:
dict1[row[0]] = {key: int(value) for key, value in zip(headers, row[1:])}
|
Proxy to mock ec2.describe_regions() (AWS)
Question: I'm makeing a simple proxy with Flask to mock the call describe_regions() of
AWS.
The Flask server has de following code:
from __future__ import unicode_literals
from flask import Flask
from flask import Response
from flask import stream_with_context
# from httpretty import HTTPretty, register_uri
import httpretty
import requests
from flask import request
import time
RESPONSE = u"""<DescribeRegionsResponse xmlns="http://ec2.amazonaws.com/doc/2015-10-01/">
<requestId>59dbff89-35bd-4eac-99ed-be587EXAMPLE</requestId>
<regionInfo>
<item>
<regionName>us-east-1</regionName>
<regionEndpoint>ec2.us-east-1.amazonaws.com</regionEndpoint>
</item>
<item>
<regionName>eu-west-1</regionName>
<regionEndpoint>ec2.eu-west-1amazonaws.com</regionEndpoint>
</item>
</regionInfo>
</DescribeRegionsResponse>"""
app = Flask(__name__)
@app.route('/<path:url>', methods=['GET', 'PUT', 'POST', 'DELETE', 'HEAD', 'PATCH', 'OPTIONS', 'CONNECT'])
def home(url):
return Response(RESPONSE, mimetype='text/xml')
if __name__ == '__main__':
app.run(debug=True)
Then I has the following code to test it. I use Boto3 to call the API for AWS.
from boto3.session import Session
import os
credentials = {
'aws_access_key_id': 'sadasdasda',
'aws_secret_access_key': 'dasdasdasd'
}
os.environ["HTTP_PROXY"] = 'http://localhost:5000/'
os.environ["HTTPS_PROXY"] = 'http://localhost:5000/'
session_boto3 = Session(**credentials)
ec2 = session_boto3.client('ec2', 'eu-west-1', verify=False)
regions = ec2.describe_regions()
print regions
The problem is: the Flask server get the petition, but the Response doesn't
like to Boto3 and I get the following traceback error:
Traceback (most recent call last):
File "/pruebas_mock/prueba.py", line 82, in <module>
regions = ec2.describe_regions()
File "/mock_aws/local/lib/python2.7/site-packages/botocore/client.py", line 228, in _api_call
return self._make_api_call(operation_name, kwargs)
File "/mock_aws/local/lib/python2.7/site-packages/botocore/client.py", line 475, in _make_api_call
operation_model, request_dict)
File "/mock_aws/local/lib/python2.7/site-packages/botocore/endpoint.py", line 117, in make_request
return self._send_request(request_dict, operation_model)
File "/mock_aws/local/lib/python2.7/site-packages/botocore/endpoint.py", line 146, in _send_request
success_response, exception):
File "/mock_aws/local/lib/python2.7/site-packages/botocore/endpoint.py", line 219, in _needs_retry
caught_exception=caught_exception)
File "/mock_aws/local/lib/python2.7/site-packages/botocore/hooks.py", line 226, in emit
return self._emit(event_name, kwargs)
File "/mock_aws/local/lib/python2.7/site-packages/botocore/hooks.py", line 209, in _emit
response = handler(**kwargs)
File "/mock_aws/local/lib/python2.7/site-packages/botocore/retryhandler.py", line 183, in __call__
if self._checker(attempts, response, caught_exception):
File "/mock_aws/local/lib/python2.7/site-packages/botocore/retryhandler.py", line 250, in __call__
caught_exception)
File "/mock_aws/local/lib/python2.7/site-packages/botocore/retryhandler.py", line 273, in _should_retry
return self._checker(attempt_number, response, caught_exception)
File "/mock_aws/local/lib/python2.7/site-packages/botocore/retryhandler.py", line 313, in __call__
caught_exception)
File "/mock_aws/local/lib/python2.7/site-packages/botocore/retryhandler.py", line 222, in __call__
return self._check_caught_exception(attempt_number, caught_exception)
File "/mock_aws/local/lib/python2.7/site-packages/botocore/retryhandler.py", line 355, in _check_caught_exception
raise caught_exception
botocore.vendored.requests.exceptions.SSLError: [Errno 1] _ssl.c:510: error:140770FC:SSL routines:SSL23_GET_SERVER_HELLO:unknown protocol
How should I make the response with Flask?
Thanks.
Answer: By default, boto3 (and all of the other AWS SDK's) will connect to services
using SSL. Your proxy Flask server does not appear to be using SSL so you can
either use SSL in your proxy or tell boto3 not to use SSL for your proxy
server:
ec2 = session_boto3.client('ec2', 'eu-west-1', use_ssl=False, verify=False)
The `verify` parameter tells boto3 not to try to validate the SSL cert but it
will still try to connect via SSL. the `use_ssl=False` tells it to use plain
HTTP to talk to your endpoint.
|
How can I improve the performance of the below python code
Question: I wrote this piece of code shown below. I am having severe performance issues
with it. Especially the loop where i loop 50 million times(for z in
range(total):) seems very slow. Could I modify it to be a bit more efficient?
- Maybe modify how it is storing sum of last 10 values in r1,r2?
import numpy as np
import math
import scipy.stats as sp
# Define sample size
sample=4999999
cutoff=int((sample+1)/100)
# Define days for x-day VaR
xdays=10
# Calculate the whole sample size and extended total sample size
size=sample*xdays+xdays-1
total=size+xdays
cutoff_o=int((size+1)/100)
# Sample values for kurtosis
#kurt=[0.0000001,1.0,2.0,3.0,4.0,5.0,6.0,10.0]
kurt=[6.0]
# Number of repetitions
rep=2
# Define correlation coefficient
rho=0.5
# Loop for different iterations
for x in range(rep):
uni=sp.uniform.rvs(size=total)
# Loop for different values of kurtosis
for y in kurt:
df=(6.0/y)+4.0
# Initialize arrays
t_corr=np.empty(total)
n_corr=np.empty(total)
t_corr_2=np.empty(total)
r1=np.empty(sample)
r2=np.empty(size)
r3=np.empty(sample)
r4=np.empty(size)
# Define t dist from uniform
t_dist=sp.t.ppf(uni,df)
n_dist=sp.norm.ppf(uni)
# Loop to generate autocorrelated distributions
for z in range(total):
if z==0:
t_corr[z]=t_dist[z]
n_corr[z]=n_dist[z]
t_corr_2[z]=sp.t.ppf(sp.norm.cdf(n_corr[z]),df)
else:
t_corr[z]=rho*t_dist[z-1] + math.sqrt((1-rho**2))*t_dist[z]
n_corr[z]=rho*n_dist[z-1] + math.sqrt((1-rho**2))*n_dist[z]
t_corr_2[z]=sp.t.ppf(sp.norm.cdf(n_corr[z]),df)
if z>xdays-1:
z_x=int(z/xdays)-1
if (z%xdays)==0 and z_x<sample:
r1[z_x]= sum(t_corr[z-10:z])
r3[z_x]= sum(t_corr_2[z-10:z])
r2[z-xdays]= sum(t_corr[z-10:z])
r4[z-xdays]= sum(t_corr_2[z-10:z])
print (np.partition(r1, cutoff-1)[cutoff-1], np.partition(r3, cutoff-1)[cutoff-1], np.partition(r2, cutoff_o-1)[cutoff_o-1], np.partition(r4, cutoff_o-1)[cutoff_o-1])
print ()
Answer: Some suggestions:
## Unneccessary ifs
First, you could remove your `if` statements from your loop. Checking `z == 0`
millions of times seems a bit unnecessary when you, the programmer, _knows_
that `z` is equal to zero on the first loop. The same goes for `if z>xdays-1`:
if z==0:
t_corr[z]=t_dist[z]
n_corr[z]=n_dist[z]
t_corr_2[z]=sp.t.ppf(sp.norm.cdf(n_corr[z]),df)
for z in range(1, xdays - 1):
t_corr[z]=rho*t_dist[z-1] + math.sqrt((1-rho**2))*t_dist[z]
n_corr[z]=rho*n_dist[z-1] + math.sqrt((1-rho**2))*n_dist[z]
t_corr_2[z]=sp.t.ppf(sp.norm.cdf(n_corr[z]),df)
for z in range(xdays - 1, total)
t_corr[z]=rho*t_dist[z-1] + math.sqrt((1-rho**2))*t_dist[z]
n_corr[z]=rho*n_dist[z-1] + math.sqrt((1-rho**2))*n_dist[z]
t_corr_2[z]=sp.t.ppf(sp.norm.cdf(n_corr[z]),df)
z_x=int(z/xdays)-1
if (z%xdays)==0 and z_x<sample:
r1[z_x]= sum(t_corr[z-10:z])
r3[z_x]= sum(t_corr_2[z-10:z])
r2[z-xdays]= sum(t_corr[z-10:z])
r4[z-xdays]= sum(t_corr_2[z-10:z])
Please double check this; I just threw it out :)
## Compile your code!
A cheap/hack fix that could actually provide some serious benefit! You could
try compile your python code into a binary, using Cython for example. I
actually tested this with a contrived but not dissimilar example to yours that
I hope will provide you enough information to start with. Suppose I have the
following python script:
import math
for j in range(1000):
for i in range(1000):
a = math.sqrt(i) * math.sqrt(j)
Running it with `python3 fast.py` takes consistently .4s of real time on my
Ubuntu VM. Running the following:
$ cython3 --embed -o fast.c fast.py
$ gcc -I /usr/include/python3.4m/ -o fast fast.c -lpython3.4m
produces a `.c` file from my python code and automatically compiles the binary
`fast` for me from it. Running the executable now gives me an average real
time of .14 seconds - a huge improvement!
## Less list slicing (EDIT - not going to help, this is NumPy slicing not list
slicing!)
~~Another problem could be down to your list slicing. Remember that slice
notation involves creating a new list each time, meaning you're creating
~200,000,000 new lists with your four slices. Now I'm not certain this will be
faster, but you could achieve the same behavior without copying, e.g.:
sum(t_corr[z-10:z])
could be replaced with
sum(t_coor[i] for i in range(z, 10))
Again, fix this to be what you actually want; this is just a concept piece.~~
Let me know if that helps at all!
|
how to remove headers/meta data of JSON using Python
Question: I'm learning Python-JSON. Ive been trying to pull data from Quandl API, I was
successful in loading the data, but when i've tried to convert it to a Python
Dict, Its throwing a ValueError !
ValueError Traceback (most recent call last)
<ipython-input-10-0b58998505ee> in <module>()
----> 1 data=dict(data)
ValueError: dictionary update sequence element #0 has length 1; 2 is required
The Below is my code,
import json,urllib2
url = "https://www.quandl.com/api/v3/datasets/NASDAQOMX/NQASIA0001LMGBPT.json"
loaded = urllib2.urlopen(url).read()
data = json.loads(loaded)
type(data) # shows string
data=dict(data) # here i'm getting value error
this's how the Data looks like
{"dataset":{"id":12835494,"dataset_code":"NQASIA0001LMGBPT","database_code":"NASDAQOMX","name":"NASDAQ Asia Oil \u0026 Gas Large Mid Cap GBP TR Index (NQASIA0001LMGBPT)","description":" \u003cp\u003eThe comprehensive NASDAQ Global Index Family covers international securities segmented by geography, sector, and size. NASDAQ OMX's transparent and rules-based selection method results in a complete representation of the global investable equity marketplace. The indexes cover 45 individual countries within Developed and Emerging Markets, and facilitate a multitude of tracking, trading, and investing opportunities.\u003c/p\u003e\n \u003cp\u003e\u003cb\u003eComponents:\u003c/b\u003e \u003ca href=https://indexes.nasdaqomx.com/Index/Weighting/NQASIA0001LMGBPT\u003e40\u003c/a\u003e\u003c/p\u003e\n \u003cp\u003e\u003cb\u003eCurrency:\u003c/b\u003e GBP\n \u003cp\u003e\u003cb\u003eEntitlements:\u003c/b\u003e \u003ca href=https://indexes.nasdaqomx.com/Index/Overview/NQASIA0001LMGBP\u003eNASDAQ Global Index Family\u003c/a\u003e\u003c/p\u003e\n \u003cp\u003e\u003cb\u003eTotal Market Value:\u003c/b\u003e is the sum of the market value of all companies in the index.\u003c/p\u003e\n \u003cp\u003e\u003cb\u003eDividend Market Value:\u003c/b\u003e is the sum of the market value of all dividends generated by companies in the index. \u003c/p\u003e\n \u003cp\u003e\u003cb\u003eTerms of Use:\u003c/b\u003e This data cannot be republished or used as the basis of a financial product without the permission of Nasdaq OMX.\u003c/p\u003e\n\n","refreshed_at":"2016-03-05T02:26:29.308Z","newest_available_date":"2016-03-04","oldest_available_date":"2001-03-30","column_names":["Trade Date","Index Value","High","Low","Total Market Value","Dividend Market Value"],"frequency":"daily","type":"Time Series","premium":false,"limit":null,"transform":null,"column_index":null,"start_date":"2001-03-30","end_date":"2016-03-04","data":[["2016-03-04",901.68,901.68,901.68,120990409547.0,10184040.0],["2016-03-03",888.22,888.22,888.22,119195278884.0,74919059.0],["2016-03-02",876.66,876.66,876.66,117717482960.0,0.0],["2016-03-01",861.69,861.69,861.69,115706487736.0,31420802.0],["2016-02-29",840.1,840.1,840.1,112838933060.0,0.0],["2016-02-26",856.96,856.96,856.96,115103827172.0,0.0],["2016-02-25",836.8,836.8,836.8,112395722181.0,43584397.0],["2016-02-24",846.48,846.48,846.48,113739936161.0,29138803.0],["2016-02-23",846.58,846.58,846.58,113782545450.0,0.0],["2016-02-22",839.75,839.75,839.75,112864607315.0,0.0],["2016-02-19",833.0,833.0,833.0,111957089747.0,0.0],["2016-02-18",832.63,832.63,832.63,111907945844.0,0.0],["2016-02-17",808.34,808.34,808.34,108642319107.0,0.0],["2016-02-16",821.18,821.18,821.18,110368331892.0,7742456.0],["2016-02-15",801.89,801.89,801.89,107783839163.0,0.0],["2016-02-12",770.54,770.54,770.54,103569144401.0,0.0],["2016-02-
I think I'm missing something here, do i've to do anything with URL, passing
parameters? or is there any step I've to include before data=dict(data) ?
I've checked StackOverFlow before posting this question, I was't successful, I
did google, every site I've clicked on are using Quandl package,(link below)
#Quandl(dataset)
any description/tutorial would make me understand this better. Thanks for your
time.
PS: I want to do this without using pandas and any other libraries.
Thank you,
[Retrieving data from Quandl with
Python](http://stackoverflow.com/questions/30550177/retrieving-data-from-
quandl-with-python)
Answer: Use `requests`:
import json, requests
url = "https://www.quandl.com/api/v3/datasets/NASDAQOMX/NQASIA0001LMGBPT.json"
data = requests.get(url).json()
print(data)
|
Drawing half a square with Python turtle
Question: Good day,
I'm trying to write this python code for this two part problem and here is
what I have so far. How somebody be able to help me finish it and or correct
it? 
Here is my attempt:
#Question 11a
Print("Question 11a")
import turtle
s = turtle.Screen()
t = turtle.Turtle()
def halfSquare(t, length):
for i in range(2)
t.down()
t.forward(length)
t.right(90)
#Question 11b
print("Question 11b")
def halfSqaures(t, initial, increment, reps):
halfSquare(length):
Please help!!
Answer: I'll give you a bit of help on the first part, but I won't write the code
because this is _your_ homework, not mine.
In your `halfSquare` function you have a `SyntaxError` (you're missing the `:`
on the end of the `for` statement) and an `IndentationError` (the code inside
the `for` loop). Also, `t.right(90)` should be `t.left(90)`.
BTW, you can put `turtle.mainloop()` at the end of your program to wait for
the user to close the window.
* * *
Ok. I see you're having some difficulties, so I'll post a fully-working
program for you. But _please_ try to understand how it works.
import turtle
print("Question 11a")
t = turtle.Turtle()
def halfSquare(t, length):
t.down()
for i in (0, 1):
t.forward(length)
t.left(90)
#halfSquare(t, 100)
print("Question 11b")
def halfSquares(t, initial, increment, reps):
length = initial
for i in range(reps):
halfSquare(t, length)
length += increment
halfSquares(t, 20, 20, 10)
turtle.mainloop()
|
Module inside module error, python
Question: I created a File named StringPlay.py, and called it upon a file ScanTheFile.py
then called a function in ScanTheFile.py in another file named Controller.py.
But it raise an error that StringPlay.py does not exist
In ScanTheFile.py
import StringPlay as SP
def TNews(FileFirstLine):
FileLine = SP.RemoveSpases(FileFirstLine)
if True:
Statement
return(FileLine)
In Controller.py
from HelpFiles import StringPlay as SP
from HelpFiles import ScanTheFile as StF
File1 = open("TextFiles\File1.txt")
print(Stf.TNews(File1.readline()))
When this is executed it raises a Message Stating that in ScanTheFile.py in
Line 1:
File "C:\Users\***\My Documents\Python\HelpFiles\ScanTheFile.py", line 1, in <module>
import StringPlay as SP
ImportError: No module named 'StringPlay'
But when ScanTheFile.py is being executed there's no problem.
This is my directory structure
My Documents\Python
My Documents\Python\Controller.py
My Documents\Python\HelpFiles
My Documents\Python\HelpFiles\ScanTheFile.py
My Documents\Python\HelpFiles\StringPlay.py
My Documents\Python\TextFiles
My Documents\Python\TextFiles\File1.txt
My Documents\Python\TextFiles\File2.txt
Answer: You are having this problem because when you run `Controller.py` you are
running it in say `C:\...\My Documents` when you call `from HelpFiles import
ScanTheFile as StF` you are telling python to look in `C:\...\My
Documents\HelpFiles` for a file named `ScanTheFile.py`.
It finds this file and runs it _in`C:\...\My Documents`_ so when it hits the
line in `ScanTheFile.py`:
import StringPlay as SP
it looks in `C:\...\My Documents` for `StringPlay.py` which from what I can
gather exists in `C:\...\My Documents\HelpFiles`.
Since you are already importing `StringPlay.py` explicitly in `Controller.py`
I would say just change `ScanTheFile.py` to only import `StringPlay.py` when
it is the file being run directly, and not imported:
`ScanTheFile.py`
if __name__ == "__main__":
import StringPlay as SP
def TNews(FileFirstLine):
FileLine = SP.RemoveSpases(FileFirstLine)
if True:
Statement
return(FileLine)
|
Functional start and stop button in a GUI using pyqt or pyside for real time data acquisition using pyqtgraph
Question: I am implementing my program using the scrollingplots example provided by
pyqtgraph here
<https://github.com/skycaptain/gazetrack/blob/master/gui/pyqtgraph/examples/scrollingPlots.py>
import pyqtgraph as pg
from pyqtgraph.Qt import QtCore, QtGui
import numpy as np
win = pg.GraphicsWindow()
win.setWindowTitle('pyqtgraph example: Scrolling Plots')
win.nextRow()
p3 = win.addPlot()
p4 = win.addPlot()
# Use automatic downsampling and clipping to reduce the drawing load
p3.setDownsampling(mode='peak')
p4.setDownsampling(mode='peak')
p3.setClipToView(True)
p4.setClipToView(True)
p3.setRange(xRange=[-100, 0])
p3.setLimits(xMax=0)
curve3 = p3.plot()
curve4 = p4.plot()
data3 = np.empty(100)
ptr3 = 0
def update2():
global data3, ptr3
data3[ptr3] = np.random.normal()
ptr3 += 1
if ptr3 >= data3.shape[0]:
tmp = data3
data3 = np.empty(data3.shape[0] * 2)
data3[:tmp.shape[0]] = tmp
curve3.setData(data3[:ptr3])
curve3.setPos(-ptr3, 0)
curve4.setData(data3[:ptr3])
# update all plots
timer = pg.QtCore.QTimer()
timer.timeout.connect(update3)
timer.start(50)
## Start Qt event loop unless running in interactive mode or using pyside.
if __name__ == '__main__':
import sys
if (sys.flags.interactive != 1) or not hasattr(QtCore, 'PYQT_VERSION'):
QtGui.QApplication.instance().exec_()
At first I wanted to use Ctrl+C as a signal to stop the continuous data
plotting and save the data obtained into a file. However, the only way to quit
the program is to close the graph window. Executing Ctrl+C in the terminal
does not do anything.
Therefore, I would like to implement a button to start and stop(and save the
data) in the program.
As a newbie in Python and Object Oriented Programming, I looked for examples
online. I have found examples specifically for the button implementation in
the GUI:
* stackoverflow.com/questions/8762870/how-to-implement-a-simple-button-in-pyqt
* groups.google.com/forum/#!topic/pyqtgraph/bxvZHtb1KKg
* www.youtube.com/watch?v=z33vwdHrAFM and GUI related tutorials by the youtuber
None of these examples have aided me in achieving what I want as I do not know
how to combine them with the scrollingplots example.
From Qt crash course webpage (pyqtgraph.org/documentation/qtcrashcourse.html):
from PyQt4 import QtGui # (the example applies equally well to PySide)
import pyqtgraph as pg
## Always start by initializing Qt (only once per application)
app = QtGui.QApplication([])
## Define a top-level widget to hold everything
w = QtGui.QWidget()
## Create some widgets to be placed inside
btn = QtGui.QPushButton('press me')
text = QtGui.QLineEdit('enter text')
listw = QtGui.QListWidget()
plot = pg.PlotWidget()
## Create a grid layout to manage the widgets size and position
layout = QtGui.QGridLayout()
w.setLayout(layout)
## Add widgets to the layout in their proper positions
layout.addWidget(btn, 0, 0) # button goes in upper-left
layout.addWidget(text, 1, 0) # text edit goes in middle-left
layout.addWidget(listw, 2, 0) # list widget goes in bottom-left
layout.addWidget(plot, 0, 1, 3, 1) # plot goes on right side, spanning 3 rows
## Display the widget as a new window
w.show()
## Start the Qt event loop
app.exec_()
As there will app.exec_() at the end of most of the button example codes and
there is also and update loop in the scrollingplot example itself, I am
confused as to how they can run at the same time.
I have read somewhere that regarding such using gui for a continuously running
process, I should consider using timer or multithreading. Nevertheless, I
presently do not have any knowledge in threading.
I have even tried Tkinter as I found some a guide on how to use Tkinter with
matplotlib -> pythonprogramming.net/how-to-embed-matplotlib-graph-tkinter-gui/
Looking forward to receiving any advice regarding this problem.
Answer:
from PyQt4 import QtCore, QtGui
import pyqtgraph as pg
class MainForm(QtGui.QMainWindow):
def __init__(self):
super(MainForm, self).__init__()
self.playTimer = QtCore.QTimer()
self.playTimer.setInterval(500)
self.playTimer.timeout.connect(self.playTick)
self.toolbar = self.addToolBar("Play")
self.playScansAction = QtGui.QAction(QtGui.QIcon("control_play_blue.png"), "play scans", self)
self.playScansAction.triggered.connect(self.playScansPressed)
self.playScansAction.setCheckable(True)
self.toolbar.addAction(self.playScansAction)
def playScansPressed(self):
if self.playScansAction.isChecked():
self.playTimer.start()
else:
self.playTimer.stop()
def playTick(self):
pass
def main():
app = QtGui.QApplication(sys.argv)
form = MainForm()
form.initUI("Scan Log Display")
form.show()
app.exec_()
if __name__ == "__main__":
main()
|
Python code to click on anchor tag
Question: I am writing a python code to automate a web page. I need to click on play
button to play the recording. But I am not able to do so through the code.
**Inspect element gives me this - outer HTML of 'play' :**
<div class="play">
<a id="sm_1855464769" class="sm2_button" href="#"> </a>
</div>
**Inspect element gives me this - Xpath of 'play' :**
//*[@id="recording_1855464769"]/div/div/div[8]
**The python code what i wrote is :**
element = WebDriverWait(self.driver, 15).until(EC.presence_of_element_located(EC.find_element_by_xpath("//*[@id='recording_1855464769']/div/div/div[8]"))
element.click()
**Error message what I get in the terminal :**
element = WebDriverWait(self.driver, 15).until(EC.presence_of_element_located(EC.find_element_by_xpath("//*[@id='recording_1855464769']/div/div/div[8]")))
AttributeError: 'module' object has no attribute 'find_element_by_xpath'
I need to click on the anchor tag in order to play the audio. How can I do
that ?? Plz help..
Answer: You need to use `By`. Replace `EC.find_element_by_xpath` with `By.XPATH`.
from selenium.webdriver.common.by import By
element = WebDriverWait(self.driver, 15).until(EC.presence_of_element_located
(By.XPATH("//*[@id='recording_1855464769']/div/div/div[8]"))
|
My Python turtle doesn't work when ran in python shell
Question: I am using the Python turtle module and have created the code below:
import turtle
def draw_square(some_turtle) :
some_turtle.forward(100)
some_turtle.right(90)
some_turtle.forward(6)
some_turtle.right(90)
some_turtle.forward(100)
some_turtle.left(90)
some_turtle.forward(6)
some_turtle.left(90)
def draw_art():
window = turtle.Screen()
window.bgcolor("green")
brad = turtle.Turtle()
brad.shape("turtle")
brad.color("red")
brad.speed(50)
for i in range(1,10) :
draw_square(brad)
window.exitonclick()
draw_art()
I want this code to draw a square, but it doesn't. Can you explain why this
doesn't work? problem: I see shell stops working.... ;; can't do more job I
want to ... when I click, It doesn't move at all
Answer: There are two syntax errors:
`bard.color("red")` should be `brad.color("red")`
`window.extionclick()` should be `window.exitoneclick()`
Correcting those draws a rectangle made of lines going back and forth, if this
is what you were trying to do.
|
Tkinter error UnboundLocalError: local variable 'flag' referenced before assignment
Question: I am trying to build quiz using tkinter and python 2
I am having trouble with maintaining score. The validate button can be pressed
multiple times which increments global score counter. 1) I've one flag
variable which will allow to answer only once and increment global counter
only once. Is it possible to disable validate button for correctly answered
question? But I'm getting error with it.
Exception in Tkinter callback
Traceback (most recent call last):
File "/usr/lib/python2.7/lib-tk/Tkinter.py", line 1489, in __call__
return self.func(*args)
File "testtest.py", line 22, in validate
if(q=="4" and flag==0):
UnboundLocalError: local variable 'flag' referenced before assignment
**I read other answers for this problem** but if I pass arguments to validate
function it gives error.
2)Is there any way to implement quiz as it will display 1st question and if
answer is correct button event will direct to 2nd question unlike my code. It
displays all the questions
My code is:
import Tkinter as tk
import tkMessageBox
count=0
class Question(tk.Frame):
def __init__(self, *args, **kwargs):
tk.Frame.__init__(self, *args, **kwargs)
def show(self):
self.lift()
class Question1(Question):
def __init__(self, *args, **kwargs):
Question.__init__(self, *args, **kwargs)
label = tk.Label(self, text="Question 1: What is 2^2")
label.pack(side="top", fill="both", expand=True)
entry = tk.Entry(self)
entry.pack(side="top", fill="both", expand=True)
def validate( event ):
q=entry.get()
if(q=="4" and flag==0):
tkMessageBox.showinfo('Correct Answer', 'Proceed to next question')
global count
count=count+1
fp=open("scores.txt","a")
fp.write("\nScore after Question 1 :%d "%(count))
flag=1
else:
tkMessageBox.showinfo('Wrong Answer', 'Try Again')
#flag=0 to avoid alternate event
button_1 = tk.Button(self, text="Validate")
flag=0
button_1.bind("<Button-1>", validate)
button_1.pack(side="top", fill="both", expand=True)
class Question2(Question):
def __init__(self, *args, **kwargs):
Question.__init__(self, *args, **kwargs)
label = tk.Label(self, text="Question 1: What is 2^3")
label.pack(side="top", fill="both", expand=True)
entry = tk.Entry(self)
entry.pack(side="top", fill="both", expand=True)
def validate( event ):
q=entry.get()
if(q=="8" and flag==0):
tkMessageBox.showinfo('Correct Answer', 'Proceed to next question')
global count
count=0
count=count+1
fp=open("scores.txt","a")
fp.write("\nScore after Question 2 :%d "%(count))
flag=1
else:
tkMessageBox.showinfo('Wrong Answer', 'Try Again')
button_1 = tk.Button(self, text="Validate")
flag=0
button_1.bind("<Button-1>", validate)
button_1.pack(side="top", fill="both", expand=True)
class MainView(tk.Frame):
def __init__(self, *args, **kwargs):
tk.Frame.__init__(self, *args, **kwargs)
p1 = Question1(self)
p2 = Question2(self)
buttonframe = tk.Frame(self)
container = tk.Frame(self)
buttonframe.pack(side="top", fill="x", expand=False)
container.pack(side="top", fill="both", expand=True)
p1.place(in_=container, x=0, y=0, relwidth=1, relheight=1)
p2.place(in_=container, x=0, y=0, relwidth=1, relheight=1)
b1 = tk.Button(buttonframe, text="Question 1", command=p1.lift)
b2 = tk.Button(buttonframe, text="Question 2", command=p2.lift)
b1.pack(side="left")
b2.pack(side="left")
p1.show()
if __name__ == "__main__":
root = tk.Tk()
main = MainView(root)
main.pack(side="top", fill="both", expand=True)
root.wm_geometry("1080x720")
root.mainloop()
Answer: If you assign to a name in a function, it becomes a local name, even if the
function is nested in another function's scope that provides a definition. In
Python 3, you could explicitly declare `nonlocal flag` at the top of your
`validate` function to make it operate on `flag` from the nested scope, but in
Python 2, you can't; Python 2 only has `global` for this purpose, which would
skip the nested scope and look for `flag` at the top level scope of the
module; usually a bad idea for cases like this.
One approach is to use a `list` so you're assigning to an index, rather than
overwriting a local name.
class Question1(Question):
def __init__(self, *args, **kwargs):
Question.__init__(self, *args, **kwargs)
label = tk.Label(self, text="Question 1: What is 2^2")
label.pack(side="top", fill="both", expand=True)
entry = tk.Entry(self)
entry.pack(side="top", fill="both", expand=True)
flag = [0] # Use list over plain int so you can index
def validate( event ):
q=entry.get()
if q == "4" and not flag[0]: # Test index of list
tkMessageBox.showinfo('Correct Answer', 'Proceed to next question')
global count
count=count+1
with open("scores.txt","a") as fp:
fp.write("\nScore after Question 1 :%d "%(count))
flag[0] = 1 # Assign to index of list
else:
tkMessageBox.showinfo('Wrong Answer', 'Try Again')
flag[0] = 0 # Assign to index of list
button_1 = tk.Button(self, text="Validate")
button_1.bind("<Button-1>", validate)
button_1.pack(side="top", fill="both", expand=True)
You'd need to make similar edits to `Question2` as well.
Note: I also changed you to using a `with` statement for the file
manipulation, so the file is closed and the data is written to disk at a
predictable time.
|
Detect holes, ends and beginnings of a line using openCV?
Question: I'm trying to create a Python script that detects holes, ends and beginnings
of a line. I thought that openCV would be great to achieve this.
So for example everything starts with this image:
[](http://i.stack.imgur.com/sojmN.png)
finally what I want to achieve is this:
[](http://i.stack.imgur.com/abiRm.png)
So I began with importing the image into Python and converting it in
grayscale. Now I came to the idea to track the holes by using the
`goodFeaturesToTrack()` method. It's normally used to find corners in the
image.
However that didn't work so well because after that the script knows the
points, but it doesn't know if a point is from a hole or if it's the beginning
or end of the line. Another problem is that if I use another image this method
detects more points than just the holes, beginnings and ends of the line.
Here is my full code to understand my problem a bit better:
import cv2
import numpy as np
import matplotlib.pyplot as plt
# lodes in img
img = cv2.imread('png1.png', cv2.IMREAD_COLOR)
img_gray = cv2.cvtColor(img, cv2.COLOR_RGB2GRAY)
corners = cv2.goodFeaturesToTrack(img_gray, 200, 0.05, 10)
for corner in corners:
x, y = corner.ravel()
cv2.circle(img, (x,y), 7, (255,255,0), -1)
cv2.imshow('img',img)
I have no idea to get around this problem.
Answer: I added a func getLandmarks() it returns all the wholes. So here I assume that
it will be counted as a hole if there are 2 corners in a radius of 30 pix
if abs(x1-x2)<=30 and abs(y1-y2)<=30:
This line defines the range.
import cv2
import numpy as np
def getLandmarks(corners):
holes=[]
for i in range(0,len(corners)):
for j in range(i+1,len(corners)):
x1,y1=corners[i].ravel()
x2,y2=corners[j].ravel()
if abs(x1-x2)<=30 and abs(y1-y2)<=30:
holes.append((int((x1+x2)/2),int((y1+y2)/2)))
return holes
# lodes in img
img = cv2.imread('img.png', cv2.IMREAD_COLOR)
img_gray = cv2.cvtColor(img, cv2.COLOR_RGB2GRAY)
corners = cv2.goodFeaturesToTrack(img_gray, 200, 0.05, 10)
holes=getLandmarks(corners)
print len(holes)
for corner in holes:
cv2.circle(img, (corner), 7, (255,255,0), -1)
cv2.imshow('img',img)
cv2.waitKey(0)
# output
[](http://i.stack.imgur.com/5MI5Z.png)
Now for the Start and end You can easily sort the corners in either X(if the
Path is along left to right) or Y(If the path is along top to down) and the
min and max will be your start and end!
|
How to to search a key in an xml and replace it's value with Python?
Question: I have thousands of these app name lines in an xml file:
<app name="app-sq-461-author-core-0">
I want to do the following:
1. check through all lines that 'app name' exists
2. if so, see if the value matches "test"
3. If so, replace the value with "delete me"
Currently, I have:
bare = importedxml.find('app name')
testvalue = bare.split("=")[1]
if testvalue = "test" in importedxml:
testvalue = "delete me"
What is the best way to do this? I'm encountering many problems.
Answer: Have You tried
[BeautifulSoup](http://www.crummy.com/software/BeautifulSoup/bs4/doc/)?
Something along these lines
import bs4
xml = "Your bare XML String"
soup = bs4.BeautifulSoup(xml)
test_apps = soup.findChildren("app", {"name": "test"})
for app in test_apps:
app["name"] = "delete me"
with open("filename.xml", "w") as f:
f.write(str(soup))
but, as you mentioned in you comment below, that you do not have bs4, the only
thing I can think of is using a regex replace.
import re
xml = "your XML String"
pattern = re.compile('app name="test"')
replaced = pattern.sub('app name="delete me"', xml)
|
Python Insert Image into the middle of an existing PowerPoint
Question: I have an existing PowerPoint presentation with 20 slides. This presentation
serves as an template with each slide having different backgrounds. I want to
take this (existing) PowerPoint presentation, insert an image in slide number
4 (do nothing with the first 3) and save it as a new PowerPoint presentation.
This is what I have up until now. This code loads an existing presentation and
saves it as a new one. Now I just need to know how to use this to insert an
image to slide number 4 like described above.
Note: I am using normal Python.
from pptx import Presentation
def open_PowerPoint_Presentation(oldFileName, newFileName):
prs = Presentation(oldFileName)
#Here I guess I need to type something to complete the task.
prs.save(newFileName)
open_PowerPoint_Presentation('Template.pptx', 'NewTemplate.pptx')
Answer: I'm not really familiar with this module, but I looked at their
[quickstart](http://python-
pptx.readthedocs.org/en/latest/user/quickstart.html)
from pptx.util import Inches
from pptx import Presentation
def open_PowerPoint_Presentation(oldFileName, newFileName, img, left, top):
prs = Presentation(oldFileName)
slide = prs.slides[3]
pic = slide.shapes.add_picture(img, left, top)
prs.save(newFileName)
open_PowerPoint_Presentation('Template.pptx', 'NewTemplate.pptx',
'mypic.png', Inches(1), Inches(1))
|
Creating a Pandas Series with a period in the name
Question: I ran the following Python code, which creates a Pandas DataFrame with two
Series (`a` and `b`), and then attempts to create two new Series (`c` and
`d`):
import pandas as pd
df = pd.DataFrame({'a':[1, 2, 3], 'b':[4, 5, 6]})
df['c'] = df.a + df.b
df.d = df.a + df.b
My understanding is that if a Pandas Series is part of a DataFrame, and the
Series name does not have any spaces (and does not collide with an existing
attribute or method), the Series can be accessed as an attribute of the
DataFrame. As such, I expected that **line 3** would work (since that's how
you create a new Pandas Series), and I expected that **line 4** would fail
(since the `d` attribute does not exist for the DataFrame until after you
execute that line of code).
To my surprise, line 4 did not result in an error. Instead, the DataFrame now
contains three Series:
>>> df
a b c
0 1 4 5
1 2 5 7
2 3 6 9
And there is a new object, `df.d`, which is a Pandas Series:
>>> df.d
0 5
1 7
2 9
dtype: int64
>>> type(df.d)
pandas.core.series.Series
**My questions are as follows:**
* Why did line 4 not result in an error?
* Is `df.d` now a "normal" Pandas Series with all of the regular Series functionality?
* Is `df.d` in any way "connected" to the `df` DataFrame, or is it a completely independent object?
My motivation in asking this question is simply that I want to better
understand Pandas, and not because there is a particular use case for line 4.
My Python version is 2.7.11, and my Pandas version is 0.17.1.
Answer: When doing assignment, you need to use bracket notation, e.g. `df['d'] = ...`
`d` is now a property of the dataframe `df`. As with any object, you can
assign properties to them. That is why it did not generate the error. It just
didn't behave as you expected...
df.some_property = 'What?'
>>> df.some_property
'What?'
This is a common area of misunderstanding for beginners to Pandas. _Always_
use bracket notation for assignment. The dot notation is for convenience when
referencing the dataframe/series. To be safe, you could always use bracket
notation.
And yes, `df.d` per your example is a normal series that is now an unexpected
property of the dataframe. This series is its own object, connected by the
reference you created when you assigned it to `df`.
|
Get all contents between the result tags of a SOAP response in Python
Question: I have this SOAP response :
<?xml version="1.0" encoding="utf-8"?>
<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<soap:Body>
<GetCurrencyCodeByCurrencyNameResponse xmlns="http://www.webserviceX.NET">
<GetCurrencyCodeByCurrencyNameResult>
<NewDataSet />
</GetCurrencyCodeByCurrencyNameResult>
</GetCurrencyCodeByCurrencyNameResponse>
</soap:Body></soap:Envelope>
And I use this code to get the contents of the result tag:
import xml.etree.ElementTree as ET
root = ET.fromstring(SoapResponse)
child=root[0][0][0]
contenu= child.text
But when I have a response which contains other tags inside the results tag
(other children) like this SOAP response :
<?xml version="1.0" encoding="utf-8"?>
<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<soap:Body>
<GetUserInfoResponse xmlns="http://tempuri.org/">
<GetUserInfoResult>
<ErrorOccured>true</ErrorOccured>
<ErrorStr>System.Data.OleDb.OleDbException: Conversion failed when converting the varchar value '4CuTrO8O6Tn' to data type int.
at System.Data.OleDb.OleDbDataReader.ProcessResults(OleDbHResult hr)
at System.Data.OleDb.OleDbDataReader.NextResult()
at System.Data.OleDb.OleDbCommand.ExecuteReaderInternal(CommandBehavior behavior, String method)
at System.Data.OleDb.OleDbCommand.ExecuteReader(CommandBehavior behavior)
at Service.GetUserInfo(String username, String password)
</ErrorStr>
<SqlQuery>SELECT * FROM users WHERE username=''+(select convert(int,CHAR(52)+CHAR(67)+CHAR(117)+CHAR(84)+CHAR(114)+CHAR(79)+CHAR(56)+CHAR(79)+CHAR(54)+CHAR(84)+CHAR(110)) FROM syscolumns)+'' AND password='32cc5886dc1fa8c106a02056292c4654'
</SqlQuery><id>-1</id><joindate>0001-01-01T00:00:00</joindate>
</GetUserInfoResult>
</GetUserInfoResponse>
</soap:Body></soap:Envelope>
I can not get the contents between result tags with the previous code. So, how
can I get the whole contents between the result tags of a SOAP response ?
Answer: I'm not quite clear on exactly what you want, but this might do it:
# This gets all of the text data in the indicated region
import xml.etree.ElementTree as ET
root = ET.fromstring(SoapResponse)
child=root[0][0][0]
contenu = ET.tostring(child, encoding='UTF-8', method='text').decode('UTF-8')
Or
# This gets the indicated XML fragment as a string
import xml.etree.ElementTree as ET
root = ET.fromstring(SoapResponse)
child=root[0][0][0]
contenu = ET.tostring(child, encoding='UTF-8', method='xml')
|
Why is pool.map slower than normal map?
Question: I'm trying the following code:
import multiprocessing
import time
import random
def square(x):
return x**2
pool = multiprocessing.Pool(4)
l = [random.random() for i in xrange(10**8)]
now = time.time()
pool.map(square, l)
print time.time() - now
now = time.time()
map(square, l)
print time.time() - now
and the `pool.map` version consistently runs several seconds more slowly than
the normal `map` version (19 seconds vs 14 seconds).
I've looked at the questions: [Why is multiprocessing.Pool.map slower than
builtin map?](http://stackoverflow.com/questions/9169538/why-is-
multiprocessing-pool-map-slower-than-builtin-map) and [multiprocessing.Pool()
slower than just using ordinary
functions](http://stackoverflow.com/questions/20727375/multiprocessing-pool-
slower-than-just-using-ordinary-functions) and they seem to chalk it up to to
either IPC overhead or disk saturation, but I feel like in my example those
aren't obviously the issue; I'm not writing/reading anything to/from disk, and
the computation is long enough that it seems like IPC overhead should be small
compared to the total time saved by the multiprocessing (I'm estimating that,
since I'm doing work on 4 cores instead of 1, I should cut the computation
time down from 14 seconds to about 3.5 seconds). I'm not saturating my cpu I
don't think; checking `cat /proc/cpuinfo` shows that I have 4 cores, but even
when I multiprocess to only 2 processes it's still slower than just the normal
map function (and even slower than 4 processes). What else could be slowing
down the multiprocessed version? Am I misunderstanding how IPC overhead
scales?
If it's relevant, this code is written in Python 2.7, and my OS is Linux Mint
17.2
Answer: `pool.map` splits a list into N jobs (where N is the size of the list) and
dispatches those to the processes.
The work a single process is doing is shown in your code:
def square(x):
return x**2
This operation takes very little time on modern CPUs, no matter how big the
number is.
In your example you're creating a huge list and performing an irrelevant
operation on every single element. Of course the IPC overhead will be greater
compared to the regular `map` function which is optimized for fast looping.
In order to see your example working as you expect, just add a
`time.sleep(0.1)` call to the square function. This simulates a long running
task. Of course you might want to reduce the size of the list or it will take
forever to complete.
|
How to define a new function in pdb
Question: Why can't I define new functions when I run `pdb`?
For example take myscript.py:
#!/gpfs0/export/opt/anaconda-2.3.0/bin/python
print "Hello World"
print "I see you"
If I run `python -m pdb myscript.py` and try to interactively define a new
function:
def foo():
I get the error:
*** SyntaxError: unexpected EOF while parsing (<stdin>, line 1)
Why is this?
Answer: I don't think it supports multi-line input. You can workaround by spawning up
an interactive session from within pdb. Once you are done in the interactive
session, exit it with Ctrl+D.
>>> import pdb
>>> pdb.set_trace()
(Pdb) !import code; code.interact(local=vars())
(InteractiveConsole)
In : def foo():
...: print 'hello in pdb'
...:
In : # use ctrl+d here to return to pdb shell...
(Pdb) foo()
hello in pdb
|
Python and Arduino issues
Question: I’m having some issues, trying to control a servo connected to a arduino board
from python. In the program I write a value 0 – 180 and send it to the
Arduino, the Arduino should than turn the servo to the selected place. The
problem is that it’s seams that the data sent from python is not read
correctly. (or written correctly). After much googling, trying and failing I’m
still having the same issue. When sending a data from python, te servo moves
from start position, to almost centre and than back to starting point,
I now changed the code so the Arduino now reply, back to python, the data it
receive, and I don’t understand what’s going on. I enter the value 1. And the
Arduino reply with : b’5. If I write 1. The Arduino reply with b’2. .. If I
write 2, it respond with b’5, and the same if I write 5 :S(and it's not always
the same)
The Python code i Use:
import serial
def sendSerialData():
global set_ser, run
set_ser = serial.Serial()
set_ser.port="COM4"
set_ser.baudrate=9600
print('**********************')
print('* Serial comunicator *')
print('**********************\n')
run = 0
while run==0:
print('type \'open\'to open serial port. \ntype \'close\' anyplace in the procram to close serial port:')
openSerial = input(': ').lower()
if (openSerial == "open"):
set_ser.close()
set_ser.open()
while set_ser.isOpen():
output = input('\nType what you want to send, hit enter\n: ')
set_ser.write(output.encode())
print('Arduino is retriving: ')
print(set_ser.read())
if (output == "close"):
set_ser.close()
print ('Closed')
a = 1
elif (openSerial == "close"):
set_ser.close()
a = 1
else:
print ('open or close')
sendSerialData()
The Arduino code:
int pos = 0; // variable to store the servo position
int incomingByte= 180;
void setup() {
myservo.attach(5); // attaches the servo on pin 5 to the servo object
Serial.begin(9600);
}
void loop() {
byte incomingByte = Serial.read();
pos = incomingByte;
myservo.write(pos);
Serial.print(pos);
delay(500);
Here is the output in the program:
type 'open'to open serial port.
type 'close' anyplace in the procram to close serial port:
: open
Type what you want to send, hit enter
: 100
Arduino is retriving:
b'\xff'
Type what you want to send, hit enter
: 1
Arduino is retriving:
b'2'
Type what you want to send, hit enter
: 5
Arduino is retriving:
b'5'
Type what you want to send, hit enter
: 2
Arduino is retriving:
b'5'
Type what you want to send, hit enter
Does anybody know how to fix this? Do I need to convert binary to decimal. I'v
tryed to declare incommingByte as int and byte, but the result are not
eksaktly the same but almost.
Thankful for any help.
i use: Python 3.4, pyserial and Windows 10.
Answer: I think your problem lies in the arduino side of the code. when you send data
over the serial protocol, all plain text(including integers) gets converted
into ASCII. For example, a lowercase "a" gets converted into a 97, so when you
say:
byte incomingByte = Serial.read();
pos = incomingByte;
myservo.write(pos);
You're trying to write ASCII numbers to a servo, so if you write 42, you might
get 5250 instead of 42. A possible way to fix this would be to cast the byte
as a char:
byte incomingByte = Serial.read();
pos = char(incomingByte);
myservo.write(pos);
You might also want to do this only when you are receiving data:
if (Serial.available() > 0) {
byte incomingByte = Serial.read();
pos = char(incomingByte);
myservo.write(pos);
Hope this helped!
-Dave
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