Debugging a Python Program that Hangs

[Kevin D. Smith]

I have a fairly large python program that, when a certain combination 
of options is used, hangs.  I have no idea where it is hanging, so 
simply putting in print statements to locate the spot would be quite 
difficult.  Unfortunately, ctrl-C'ing the program doesn't print a 
traceback either.  Looking through the python debugger documentation, I 
don't see how to run a python program and interactively stopping it 
while it is running.  Is there a way to stop within a running python 
program to see where it is getting hung up?

-- 
Kevin D. Smith