In attempting to solve a package management issue here, I learned I may have issues with the way I'm using PYTHONPATH to access packages outside of the site-packages directory.
I receive an import error when attempting to import modules from a package (say wxPython) from its versioned directory folder name (i.e. wx-2.8-msw-unicode) when said directory is not in the python site-packages directory.
To recreate the issue: Create a directory outside of the python directory, say C:\foo. Download wxPython, and place it in that directory (giving C:\foo\wx-2.8-msw-unicode). Add more if you like. Add the directory C:\foo to your PYTHONPATH environment variable. Open a new python interactive shell and run
import sys
for i in sys.paths:
    print i
to verify that the path is there (which it is), then
import wx
I receive an Import Error. What am I doing wrong? Is this behavior correct?