This is something that should help considerably with readability of our Python code. Running the formatting is only part of of it, we need to make sure that CI runs the checks on every push that changes the affected files as well or it's useless.
See taskcluster/ci/source-test/mozlint.yml:py-black for the CI portion. It should port fairly easily.

Bringing some sanity to our Python scripts.

Depends on D95399

Bringing some sanity to our Python scripts.

Depends on D95400

These will not be covered by CI for the moment because the global exclude does
not permit reincluding certain files. That deficiency in coverage can be addressed
in a follow-up bug.

Depends on D95402

Pushed by thunderbird@calypsoblue.org:
https://hg.mozilla.org/comm-central/rev/e2ab56cfb900
Add black formatting mozlint check to run in CI. r=justdave
https://hg.mozilla.org/comm-central/rev/340ec9b2ed5d
Run black formatting on all python files. r=mkmelin
https://hg.mozilla.org/comm-central/rev/dd6e7061f3e6
Run black formatting on mozbuild and mozconfigure files. r=mkmelin
https://hg.mozilla.org/comm-central/rev/dfaaefc00d08
Run black formatting on MZLA files in third_party. r=mkmelin

Reopened as suite has not landed. Review pending.

Pushed by thunderbird@calypsoblue.org:
https://hg.mozilla.org/comm-central/rev/6fe08c0e66a2
Follow-up: Reformat mozbuild files with black. rs=linting DONTBUILD

Pushed by thunderbird@calypsoblue.org:
https://hg.mozilla.org/comm-central/rev/4fe4863303d4
Follow-up: Reformat mozbuild files with black. rs=linting