python

Python: Implementing slicing in __getitem__

I am trying to implement slice functionality for a class I am making that creates a vector representation. I have this code so far, which I believe will properly implement the slice but whenever I do a call like v[4] where v is a vector python returns an error about not having enough parameters. So I am trying to figure out how to defin...

How to parse a directory tree in python?

I have a directory called "notes" within the notes I have categories which are named "science", "maths" ... within those folder are sub-categories, such as "Quantum Mechanics", "Linear Algebra". ./notes --> ./notes/maths ------> ./notes/maths/linear_algebra --> ./notes/physics/ ------> ./notes/physics/quantum_mechanics My problem is t...

Pygame, sounds don't play

I'm trying to play sound files (.wav) with pygame but when I start it I never hear anything. This is the code: import pygame pygame.init() pygame.mixer.init() sounda= pygame.mixer.Sound("desert_rustle.wav") sounda.play() I also tried using channels but the result is the same ...

django - variable declared in base project does not appear in app

I have a variable called STATIC_URL, declared in settings.py in my base project: STATIC_URL = '/site_media/static/' This is used, for example, in my site_base.html, which links to CSS files as follows: <link rel="stylesheet" href="{{ STATIC_URL }}css/site_tabs.css" /> I have a bunch of templates related to different apps which exte...

A UnicodeDecodeError that occurs with json in python on Windows, but not Mac.

On windows, I have the following problem: >>> string = "Don´t Forget To Breathe" >>> import json,os,codecs >>> f = codecs.open("C:\\temp.txt","w","UTF-8") >>> json.dump(string,f) Traceback (most recent call last): File "<stdin>", line 1, in <module> File "C:\Python26\lib\json\__init__.py", line 180, in dump for chunk in iterable...

Python: is not sequence

In python is there an easy way to tell if something is not a sequence? I tried to just do: if x is not sequence but python did not like that ...

Pass arguments from django-registration to django-profiles when user registers.

I'm using both django-registrations and django-profiles. When the user registers I'd like to ask them to fill in the form fields from profiles as well as the usual username and password. How do I combine these two into one sign up page? ...

How to remove commas etc from a matrix in python

say ive got a matrix that looks like: [[0, 0, 0, 0, 0], [0, 0, 0, 0, 0], [0, 0, 0, 0, 0]] how can i make it on seperate lines: [[0, 0, 0, 0, 0], [0, 0, 0, 0, 0], [0, 0, 0, 0, 0]] and then remove commas etc: 0 0 0 0 0 And also to make it blank instead of 0's, so that numbers can be put in later, so in the end it will be like: _ ...

Python: Improving long cumulative sum

I have a program that operates on a large set of experimental data. The data is stored as a list of objects that are instances of a class with the following attributes: time_point - the time of the sample cluster - the name of the cluster of nodes from which the sample was taken node - the name of the node from which the sample was ...

Using Python to get a CSV output for the following example.

Hi there, I'm back again with my ongoing saga of Student-Project Allocation questions. Thanks to Moron (who does not match his namesake) I've got a bit of direction for an evaluation portion of my project. Going with the idea of the Assignment Problem and Hungarian Algorithm I would like to express my data in the form of a .csv file ...

large amount of data in many text files - how to process?

Hi, I have large amounts of data (a few terabytes) and accumulating... They are contained in many tab-delimited flat text files (each about 30MB). Most of the task involves reading the data and aggregating (summing/averaging + additional transformations) over observations/rows based on a series of predicate statements, and then saving th...

Update model instance with dynamic field names

What I want to do is pretty simple: f=Foobar.objects.get(id=1) foo='somefield' bar='somevalue' f.foo=bar f.save() This doesn't work as it tries to update the f object's 'foo' field, which of course doesn't exist. How can I accomplish this? ...

linear combinations in python/numpy

greetings, I'm not sure if this is a dumb question or not. Lets say I have 3 numpy arrays, A1,A2,A3, and 3 floats, c1,c2,c3 and I'd like to evaluate B = A1*c1+ A2*c2+ A3*c3 will numpy compute this as for example, E1 = A1*c1 E2 = A2*c2 E3 = A3*c3 D1 = E1+E2 B = D1+E3 or is it more clever than that? In c++ I had a neat way to a...

Custom constructors for models in Google App Engine (python)

I'm getting back to programming for Google App Engine and I've found, in old, unused code, instances in which I wrote constructors for models. It seems like a good idea, but there's no mention of it online and I can't test to see if it works. Here's a contrived example, with no error-checking, etc.: class Dog(db.Model): name = db....

What is a flexible, hybrid python collection object?

As a way to get used to python, I am trying to translate some of my code to python from Autohotkey_L. I am immediately running into tons of choices for collection objects. Can you help me figure out a built in type or a 3rd party contributed type that has as much as possible, the functionality of the AutoHotkey_L object type and its m...

Django doesn't refresh my request object when reloading the current page.

I have a Django web site which I want ot be viewable in different languages. Until this morning everything was working fine. Here is the deal. I go to my say About Us page and it is in English. Below it there is the change language button and when I press it everything "magically" translates to Bulgarian just the way I want it. On the ot...

Caveats to be aware of when using threading in Python?

I'm quite new to threading in Python and have a couple of beginner questions. When starting more than say fifty threads using the Python threading module I start getting MemoryError. The threads themselves are very slim and not very memory hungry, so it seems like it is the overhead of the threading that causes the memory issues. Is t...

Sort and limit queryset by comment count and date using queryset.extra() (django)

I am trying to sort/narrow a queryset of objects based on the number of comments each object has as well as by the timeframe during which the comments were posted. Am using a queryset.extra() method (using django_comments which utilizes generic foreign keys). I got the idea for using queryset.extra() (and the code) from here. This i...

File encyption with Python

Is there a way to encrypt files (.zip, .doc, .exe, ... any type of file) with Python? I've looked at a bunch of crypto libraries for Python including pycrypto and ezpycrypto but as far as I see they only offer string encryption. ...

Subfolders in py2exe

I would like to add subfolders while creating the python script using py2exe.. The syntax I have used is -- setup(windows = [{"script":"test.py"}],data_files= [('Folder A', [('Subfolder B' ,[os.path.join('Folder A','XYZ.py')] )] )] ) What will be the correct synt...