Python does not see Macports-installed modules. Why?

[Tarage]

Hi everyone. The subject line says it all. I'm trying to get py-gtk2 
going on 10.3.9, and in that quest, I've let Macports install all the 
dependent libraries, including python24. However, when I go to the 
python prompt and run a help() then modules, it doesn't see any of the 
modules I've installed! I've experimented with adding various paths to 
the python search path, but apparently I'm not adding the right ones to 
pick up these modules. I've looked through the archives here and across 
the Web. How do I make sure that python will see the Macports-installed 
modules?

Thanks!
~Tarage