.cgi or .cgp or .py or ?

[haaserd]

Hi,
I am a newbie tinkering with python .cgi scripts on a
Windows machine.  I have it working by following the advice
at http://starship.python.net/crew/aaron_watters/pws.html
but am confused by the comment for saving .py for helper
modules.  Also another site suggested using the extension
.cgp for python.

There isn't any advice in cgi.py.  What is the recommended
naming convention?

TIA,

Roger Haase