Vim's Omnicompletion with Python just doesn't work

Question

I've searched around for an hour, both on Stack Overflow and elsewhere. Alas! Please help. Vim's omnicompletion just doesn't work.

1. I have Vim 7.2 compiled with Python support.

2. filetype plugin on is in my .vimrc.

3. When a .py file is open, :echo &omnifunc prints pythoncomplete#Complete.

4. I'm working with a large project and I have a tags file generated with exhuberant-ctags. It's in Vim's ctags path. I can test it by typing ^] on a symbol and I'm then taken to the symbols' definition.

5. Update 1: All of my project's code is in the python-in-Vim's path. I can :python import myproject successfully.

Now, anywhere I try C-x C-o, all I get is:

-- Omni completion (^O^N^P) Pattern not found

What am I doing wrong?

Update 2: When I type C-x C-o C-n at the module-level, Vim displays a completion popup with a few module-level constants from other modules in my project. But it's only constants (symbols capital letters) and the completion still doesn't work anywhere else.

Update 3: I've found that C-x C-o at the top of the file starts some kind of omnicompletion, and completion for pprint. brings up the menu and quick-reference of everything in the pprint module. However, none of my own module's imports are being completed.

Update 4, one year later: I gave up and learned Emacs. I have been to the dark side, the mystical land of intrigue and spice, and I say to thee that I have found The Way.

Update 5, two years later: I went back to Vim. Emacs is beautiful, but even after 1.5 years of Emacs, I'm still faster at getting work done in Vim. I've stopped writing Python for now, however, and can't test how well these suggestions work.

Answer 1

What module contains the symbol you are trying to complete? Is it in the python stdlib? Or is it a third-party module?

Make sure that the module/package is in the PYTHONPATH.

In Vim, do:

:python import sys
:python print sys.path

To add the module's directory:

:python sys.path.append("/path/to/directory/")