Isort: known_standard_library resets the stdlib list

[ionelmc]

If you use known_standard_library then isort simply forgets about all the other stdlib modules. It's a pretty useless option and it would only be useful if you'd fill that option with all the stdlib modules. I belive it should be additive instead, and add modules to the already known ones, instead of reseting it.

[timothycrosley]

See: https://timothycrosley.github.io/isort/docs/upgrade_guides/5.0.0/#known_standard_library. You likely want to set extra_standard_library. Really neither mode should be needed as isort's standard library listing is exhaustive from Python's own documentation.

[ionelmc]

Ooof ... yeah, I just discovered extra_standard_library after diggig into the docs. I think it should be mentioned in the readme :)

[timothycrosley]

Good call! I've added a mention to the readme :)