Learned pdb basics: http://www.ferg.org/papers/debugging_in_python.html

Wow IDLE debugger is impressive: http://www.python.org/idle/doc/idle2.html#Debugger

I was playing with 'Path Browser' in IDLE (came to know about it only today) and discovered that Berkeley DB comes with py (at least a simple interface). Just an 'import bsddb" will do.