Getting started with the Python source

[renguy]

I am interested in making some changes and additions to the Python
environment (Python and IDLE). I have the source code and can build the
source, but what I want to know is what are the "main" functions or
source code for Python and IDLE. Specifically I would like to know what
in Python and IDLE would be analogous to void main () in a standard C
program. This will help me to work out the structure of the interpreter
and the environment. Your help will be greatly appreciated. The changes
I wish to make are for investigating the modification of the Python
environment for novice programmers.