@Dreamsorcerer
may be it is better to move all of this kind of importing

if sys.version_info >= (3, 8):
    from typing import Final
else:
    from typing_extensions import Final

to typedefs.py and then import it from there. What do you think?

to typedefs.py and then import it from there. What do you think?

I'm not overly opposed to it, but I think it could make maintenance slightly more difficult. e.g. When we drop support for Python 3.7, I can currently grep for "3, 8" or "typing_extensions" to find every place that should be updated. I don't really want to leave the code importing from typedefs when it's no longer needed.

Then it could be still present in typedefs.py but without version checking.
I mean to find all occurrences is not a big problem. Just run the tests or mypy.

Yep, OK, we'll do it that way.

This pull request introduces 1 alert when merging ff09e43 into 726f44e - view on LGTM.com

new alerts:

• 1 for Unused import