logging.basicConfig uses **kwargs and does not validate them.

This caused me to shoot myself in the foot multiple times by passing logLevel instead of level accidentally, and then trying to figure out why my messages don't get logged.

New changeset 2bc3e839a3a3 by Vinay Sajip in branch '3.4':
Issue #23207: logging.basicConfig() now does additional validation of its arguments.
https://hg.python.org/cpython/rev/2bc3e839a3a3

New changeset 06ba5e776a6e by Vinay Sajip in branch 'default':
Closes #23207: logging.basicConfig() now does additional validation of its arguments.
https://hg.python.org/cpython/rev/06ba5e776a6e

The argument validation in basicConfig has introduced another problem.
I cannot pass in an optional filename/filemode argument pair.

Previously, I passed in an optional logfile argument from ArgumentParser (which could be None). Now, I get a ValueError because filemode is not popped if filename is None.

logging.basicConfig(..., filename=args.logfile, filemode="w")
...
ValueError: Unrecognised argument(s): filemode

Suggested fix to place mode assignment alongside filename in basicConfig():
    filename = kwargs.pop("filename", None)
    mode = kwargs.pop("filemode", 'a')
    if filename:
        h = FileHandler(filename, mode)

New changeset d3b420807a86 by Vinay Sajip in branch '3.4':
Issue #23207: Improved kwarg validation.
https://hg.python.org/cpython/rev/d3b420807a86

New changeset 7ff0d7b50b36 by Vinay Sajip in branch 'default':
Issue #23207: merged fix from 3.4.
https://hg.python.org/cpython/rev/7ff0d7b50b36