How should I organize Python source code?

Question

I'm getting started with Python (it's high time I give it a shot), and I'm looking for some best practices.

My first project is a queue which runs command-line experiments in multiple threads. I'm starting to get a very long main.py file, and I'd like to break it up. In general, I'm looking for: How do python programmers organize multiple source files? Is there a particular structure that works for you?

My specific questions include:

1. Should each class be in a separate file?
2. How should I organize unit tests relative to source code?
3. Where should I put doc comments, specifically those for command-line operation?
4. If I use multiple directories, how do I import classes between them?

I can probably draw some of my own conclusions here by trial and error, but I'd rather start from something good.

Answer 1

I found this article super-helpful while addressing the same problem so hopefully it helps you:

http://infinitemonkeycorps.net/docs/pph/

Answer 2

The way you should organise your code and tests is exactly the same you would for any OO language.

Answers from the way I do it. It may not be right but works for me

1. Depends on how your functionality is split. For my main python app I have 1 file with classes for the entry points and then packages of different bits of functionality
2. I use PyDev for eclipse and organise it like I would for Java.

>  Workspace
>     |
>     |-Src
>     |   |-Package1
>     |   |-Package2
>     |   |-main.py
>     |-Test
>         |-TestPackage1
>         |-TestPackage2

1. Use DocString everywhere to keep track of everything
2. After making sure that the relevant init.py files are in the folders. its just a simple case of from module import class