Which is the best way to allow configuration options be overridden at the command line in Python?

Question

I have a Python application which needs quite a few (~30) configuration parameters. Up to now, I used the OptionParser class to define default values in the app itself, with

Answer 1

Check out ConfigArgParse - its a new PyPI package (open source) that serves as a drop in replacement for argparse with added support for config files and environment variables.