[mod_python] includes/external files

hi all -
i been dealing with mod python from a couple of weeks -
but i still dont understand to make stuff as php includes
works good in a python enviromente -
im really interested in web scripting -
and i lookin for a way to use includes or external files with routines and
code to manage my web site.

can someone help me?
a link to a good refernce would be greatù
;)

thank u very much

tropiko