WinPdb is a great python debugger.
On Mac, if you run it, you may get
/usr/local/lib/wxPython-unicode-2.8.12.0/lib/python2.7/site-packages/wx-2.8-mac-unicode/wx/_core_.so: \
no matching architecture in universal wrapper
WinPdb needs to run 32bit.
$ arch -i386 winpdb test.py