Knowing the source of every argument?

[Barlerer]

I want to have the option to raise a warning if a user supplied both command-line arguments, and setting the same values in the config file. How can I achieve this?

I could also accomplish this, if I knew the source of every argument (from command-line\config)

[tbooth]

This isn't really do-able at the moment, but I have a suggestion of how this could be implemented if a new parser hook were to be added to the main code.

See example 2 in this code: https://github.com/tbooth/ConfigArgParse/blob/devel/tests/test_config_parser_subclasses.py

If there is enough enthusiasm, hopefully we can get this feature merged.