Personally I like black's style in function argument formatting better than PEP8, assuming the example given is representative of both styles; I find black's to be much more readable.

But that's of course a bikeshed.

At any rate, if black's formatting does break PEP8 (as a downthread commenter rebuts), I would think it's weird that black doesn't have a --pep8-correct flag or something for people who do want PEP-compliant stuff. Certainly black can go its own way, but if people are going to consider it "the blessed python code formatter", it should have a mode that actually conforms to the python standard for formatting.

But hey, ultimately it's the black maintainer's choice.