I'm not convinced that every change is an improvement, but it all seems to be OK. Are you planning to do more work here?

Do you have in mind the changes from str + str to f"{str}{str}"? Not sure about them either. While f-strings are faster and considered more readable in a majority of situations, they might not be an improvement here. I can revert this class of changes if you agree, absolutely not a problem.

I don't intend adding more changes (although Sourcery suggests more). I do think it might be worthwhile to add Sourcery to the repository, it provides AI assistance for PR review. I find it useful, although not bulletproof or astounding.