python

Django's Admin - Many-to-Many field confusion

I'm teaching myself Django and creating a personal portfolio site. I've setup a model called FolioItem which makes use of a Many-To-Many relation to another model called FolioImage. The idea being each FolioItem can have numerous FolioImages. class FolioImage(models.Model): image = models.FileField(upload_to='portfolio_images') ...

Convert GeoTIFF to JPEG and Extract GeoTIFF Headers in Python

I am making a Python script which will read in a GeoTIFF file, and will do both: convert the GeoTIFF into a static JPEG (that is much smaller in size), and create a separate text file which contains the GeoTIFF headers. Using the Python GDAL API, I am able to get the script to open a GeoTIFF file, and print details, such as the RasterXS...

Python Source Formatter/Pretty Printer

Is there an online or offline utility that will format/pretty-print Python source code? ...

Python read multiline JSON

I have been trying to use JSON to store settings for a program. I can't seem to get Python 2.6 's JSON Decoder to decode multi-line JSON strings... Here is example input: .settings file: """ {\ 'user':'username',\ 'password':'passwd',\ }\ """ I have tried a couple other syntaxes for this file, which I will specify below (with th...

Php and python regexp difference?

I need to parse a string 'Open URN: 100000 LA: ' and get 100000 from it. on python regexp (?<=Open URN: )[0-9]+(?= LA:) works fine but in php it gives following error: preg_match(): Unknown modifier '[' I need it working php, so please help me to solve this problem and tell about difference in python and php regexps. ...

How should I correctly handle exceptions in Python3

I can't understand what sort of exceptions I should handle 'here and now', and what sort of exceptions I should re-raise or just don't handle here, and what to do with them later (on higher tier). For example: I wrote client/server application using python3 with ssl communication. Client is supposed to verify files on any differences on ...

Script to install and compile Python, Django, Virtualenv, Mercurial, Git, LessCSS, etc... on Dreamhost

The Story After cleaning up my Dreamhost shared server's home folder from all the cruft accumulated over time, I decided to start afresh and compile/reinstall Python. All tutorials and snippets I found seemed overly simplistic, assuming (or ignoring) a bunch of dependencies needed by Python to compile all modules correctly. So, starting...

Help a Python newbie with a Django model inheritance problem

I'm working on my first real Django project after years of PHP programming, and I am running into a problem with my models. First, I noticed that I was copying and pasting code between the models, and being a diligent OO programmer I decided to make a parent class that the other models could inherit from: class Common(model.Model): ...

Why is sys.path showing non-existent items (which cause import problems)?

I'm seeing some additional items in sys.path which 1) don't exist and 2) cause problems with imports (specifically with Nose). Basically, I've created a package (lets call it foo) which I use in multiple projects. The project I'm working on at the moment can import everything from foo without issue, but when I run Nose I get import erro...

ctypes DLL with optional dependencies

Disclaimer: I'm new to windows programming so some of my assumptions may be wrong. Please correct me if so. I am developing a python wrapper for a C API using ctypes. The API ships with both 64 and 32 DLLs/LIBs. I can succesfully load the DLL using ctypes.WinDLL('TheLibName') and call functions etc etc. However some functions were not ...

Why do I get a segmentation fault while redirecting sys.stdout to Tkinter.Text widget in Python?

I'm in the process of building a GUI-based application with Python/Tkinter that builds on top of the existing Python bdb module. In this application, I want to silence all stdout/stderr from the console and redirect it to my GUI. To accomplish this purpose, I've written a specialized Tkinter.Text object (code at the end of the post). ...

How does Blippy get its data

I was wondering how Blippy is able to get my data? It requires me to put in my bank name, bank card number and password, so is it doing a simple website scrape by logging in? My bank, however also requires a seperate passphrase as well. How does it get around that? Can urllib and such libraries be used in Python to replicate Blippy fun...

wxPython ListCtrl Column Ignores Specific Fields

I'm rewriting this post to clarify some things and provide a full class definition for the Virtual List I'm having trouble with. The class is defined like so: from wx import ListCtrl, LC_REPORT, LC_VIRTUAL, LC_HRULES, LC_VRULES, \ EVT_LIST_COL_CLICK, EVT_LIST_CACHE_HINT, EVT_LIST_COL_RIGHT_CLICK, \ ImageList, IMAGE_LIST_SMALL, Men...

How can I share data (which is updated every minute) accoss modules in Python?

I have read in many posts that global variables are bad, but I need them! My situation: I have few variables defined in a dedicated module which are updated every minute and are used by other modules in the application. (Implemented after reading this), Do you think its a good approach or needs any improvement or any better idea? Than...

varargs in lambda functions in Python

Is it possible a lambda function to have variable number of arguments? For example, I want to write a metaclass, which creates a method for every method of some other class and this newly created method returns the opposite value of the original method and has the same number of arguments. And I want to do this with lambda function. How...

Sending file over socket

I'm have a problem sending data as a file from one end of a socket to the other. What's happening is that both the server and client are trying to read the file so the file never gets sent. I was wondering how to have the client block until the server's completed reading the file sent from the client. I have this working with raw packet...

Saving a Django form to a csv file

I have a Django form that is working fine. I'd like to save the data it submits to a CSV file. Is there a "best practice" way to do this? I need to include blank fields in the CSV file where the user has not filled in a "required=False" field ...

How to optimize this Python code?

def maxVote(nLabels): count = {} maxList = [] maxCount = 0 for nLabel in nLabels: if nLabel in count: count[nLabel] += 1 else: count[nLabel] = 1 #Check if the count is max if count[nLabel] > maxCount: maxCount = count[nLabel] maxList = [nLabel,] ...

How do I abort a socket.recv() from another thread in python?

I have a main thread that waits for connection. It spawns client threads that will echo the response from the client (telnet in this case). But say that I want to close down all sockets and all threads after some time, like after 1 connection. How would I do? If I do clientSocket.close() from the main thread, it won't stop doing the recv...

Unit Testing Interfaces in Python

I am currently learning python in preperation for a class over the summer and have gotten started by implementing different types of heaps and priority based data structures. I began to write a unit test suite for the project but ran into difficulties into creating a generic unit test that only tests the interface and is oblivious of th...