Intuitive solution: Misuse print() statements for debugging. Better in the long term: Add proper logging to your application!
Shell: $> python -m pdb <yourcode.py> Inline: import pdb; pdb.set_trace()
at your service since Python 1.4 (1996)
It would seem that David and other renowned people from the community do not use/like/need debuggers: Your mileage may vary.