How to write python plug-ins for your own python program?

[Tian]

I am writing an audio game using Python. in this game you can apply
some sound effects for the clips you have recorded. I want to make this
function extensible. I want user to be able to add new sound effect
plug-ins in the future.

I want the plug-in to be a simple python code (text file) and a
description file. I will set some rules for plug-in writing (like you
must inherit some class and implement some method). I hope plugin can
be added while original program is running. Is there any good method to
read in python code and test availability and invoke the functions
inside?

Thanks


Tian