Terminating python script easily

[Balban]

Hi,

I have a python build script that calls various commands, some using
os.system().

Often, if I want to terminate the script prematurely, I press ctrl-c,
but I have to do this many times before I can kill the script for
good. I was wondering is there a way that I define a signal handler
and kill the whole thing at once with a single ctrl-c? Perhaps I
should  also call my other scripts with a method other than os.system
() as well?

Thank you,

Bahadir