Looking for a way to include Pyhtho scripting INSIDE a python program

[John Antypas]

Hello all,

I'm writing in tool in Python that manipulates various data objects read 
from various streams.  I wanted to give the user a chance to do advanced 
work that could not easily be done from a GUI.

At first, I tried putting in a lightweight scripting language, and then 
I thought, why not include Python in itself -- it is certainly powerful 
enough.

I had assumed I'd present the user with a text window in which they 
could type arbitrary python code.  I'd wrap that code around a function 
and pass that function a call of objects they could manipulate by 
calling the methods of that class.

1. How can a python program invoke ANOTHER interpreter?
2. How can I pass the class in as its argument and get the modified 
class back?

I know I can do something very ugly -- call a C method that calls a new 
python interpreter but that seems VERY ugly.

Help?

Thanks.