My current favorite Python source code documentation system is Epydoc. It's what I use for any non-trivial Python program.

Installation

Installation on Ubuntu is very easy:

$ sudo apt-get install python-epydoc epydoc-doc

If you are on any platform where setuptools is available, then you can just do this:

$ sudo easy_install epydoc

Sample Usage

This will print out great help:

$ epydoc --help

This will generate documentation for all of the listed modules. The -v option says to be verbose. Output will go to the docs directory.

$ epydoc -o docs -v module1 module2 ...