Thanks for the review @cdce8p!

I left two small comments where I think a trailing comma could be useful.

I tried adding these, but black just strips them away again ;)

I left two small comments where I think a trailing comma could be useful.

I tried adding these, but black just strips them away again ;)

Found the issue

The magic-trailing-comma isn't perfect but IMO it works well enough. I would recommend to remove that setting.
https://black.readthedocs.io/en/stable/the_black_code_style/current_style.html#the-magic-trailing-comma

Found the issue

mypy/pyproject.toml

Line 11 in f8fc26e

skip-magic-trailing-comma = true

Good catch! I think it was @hauntsaninja that recommended enabling that setting in the initial refactor-for-black PR.

Whatever the wisdom of that setting, however, I'm not going to change that in this PR, since it's slightly tangential to this PR's purpose :-)

I don't like the magic trailing comma and I would not like that setting changed.

I don't like the magic trailing comma and I would not like that setting changed.

It might not be perfect but what I like about it is it at least gives you the option to choose a better formatting if it makes sense. I opened #13418 to show the impact of removing the option.