I (Edgar Merino) have ported the Parport library for Java created by Juan Gabriel del Cid Portillo to Python, simply to control the Parallel Port in both windows and gnu/linux. It provides an easy yet very useful interactive mode to access the parallel port from within the python shell:
from parport import *
send(D0) //Write to DATA PIN 1
send(D0+D1+D2) //Write to DATA PINS 1,2 and 3
 

This library depends on C only.

For windows users: you'll need UserPort in order to access the parallel port (WinXP and maybe others).

RELEASED UNDER THE GNU GPL
Installation: Just uncompress the zip file where you want to use it (for example, the root folder of your proyect :). On windows you'll need to compile the shared library, included in the src directory.

TODO: provide the library with an installer and the windows DLL already compiled.