Replace types-SQLAlchemy requirement with SQLAlchemy in Flask-SQLAlchemy

[kkirsche]

This removes the types-SQLAlchemy requirement from Flask-SQLAlchemy because the user may instead be using sqlalchemy-provided stubs rather than third-party stubs.

If there is a way to instead make this conditional, this should be closed and that approach should be used instead to isolate the version appropriately.

[kkirsche]

Sounds like maybe this should be an issue instead :/ from the pre-commit results

[AlexWaygood]

There's two things that don't make this possible yet, unfortunately:

• We currently don't have the infrastructure set up to allow non-types dependencies in typeshed: Allow non-types dependencies #5768
• SQLAlchemy now has inline type annotations for much of its code, and has a py.typed file on its master branch. But the most recent release (1.4.39) doesn't have a py.typed file. Without a py.typed file, the type annotations are only for internal use; a type-checker won't be able to see them and use them if SQLAlchemy is installed as a package. Until SQLAlchemy cuts a release with a py.typed file, typeshed's types-SQLAlchemy stubs will still be necessary.

[srittau]

It's currently not possible to depend on non-type packages from typeshed packages. Also, SQLAlchemy doesn't ship with a py.typed file at the moment, so its type annotation won't be used. SQLAlchemy 2 will include the py.typed file if I understand correctly.

[kkirsche]

Ah, that's too bad. I was really hoping it'd be possible to use the sqlalchemy sqlalchemy2-stubs with this type set as this would drastically simplify working with Flask-SQLAlchemy for users on 1.4 who use their official mypy stubs

[kkirsche]

Thank you for the information though and sorry for the incorrect PR

[srittau]

If there are useful types from sqlalchemy2-stubs that aren't in types-sqlalchemy yet, I believe it would be useful to have them integrated.

[AlexWaygood]

No worries, thanks for the PR, even if it wasn't successful! :)

[github-actions]

According to mypy_primer, this change has no effect on the checked open source code. 🤖🎉