[SQLAlchemy] Annotate row classes

[srittau]

No description provided.

[srittau]

The new homeassistant warning is due the comment I left about Row.count.

https://github.com/home-assistant/core/blob/37c1052cceadec109d681ec3bced6c3f96a5863c/homeassistant/components/recorder/statistics.py#L1184

The comment:

    # The count and index methods are inherited from Sequence.
    # If the result set contains columns with the same names, these
    # fields contains their respective values, instead. We don't reflect
    # this in the stubs.

While we could of course type count and index as Any, I think an explicit cast here is actually advantageous as it's a clear sign that something "interesting" is going on here and it's not the normal Sequence.count field that is being used.

[Avasam]

Is this another case for a permissive union? count: AnyOf[Callable[[Any], int], int]

Maybe not if it's not that common. If a user knows they's using count and index column
(or any other column name that overrides an existing property) they could possibly subtype Row and explicitly set the type for their class. Or just use a cast.

[JelleZijlstra]

@srittau could you respond to Avasam's feedback?

[github-actions]

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

[srittau]

Whoops, I forgot about this PR. Thanks, @Avasam for the thorough PR. I think I addressed all the concerns, although I fixed things a bit differently.