🔒 Dynamic Classes: MYPY saying `Variable is not valid as a type`, any suggested fixes?

[cobalt plover]

Firstly, you can peep the example code here: https://paste.pythondiscord.com/EZ6Q

My big question here is why does class A seem fine to MyPy, but class B gives an error? Is there some way I can make the function B work? It's for instances when the bar_cls arguments fulfill my "modifications" to the class, and I don't need to define a class using the class keyword as I won't need to modify it's inner functions or anything. If the answer is that I just need to construct all of these subclasses like A then I guess that works too.

Using python 3.12

[opal berry]

@cobalt plover

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[sacred vapor]

what line?

I suspect at least 14, 19, 25, 26

37, 37, 38, 38, 46, 46

47

[cobalt plover]

sorry, on line 62 where I have put the comment with the error

[sacred vapor]

oh, I thought those with lowercase t in type would have cause mypy complain

[cobalt plover]

I think mypy is fine with type instead of Type now. Using 3.12 too which might have been relevant

the error I commented in the code is the only mypy error that shows up

[coral ingot]

I'm not exactly sure why, but I don't think using a type returned from a function like that is supported. You can see what is seen as a valid type expression here https://typing.readthedocs.io/en/latest/spec/annotations.html#type-and-annotation-expressions

[cobalt plover]

im guessing there is something different enough about creating a class with type vs using the class keyword that it doesn't like for some reason. Even though to me, it should essentially be the same thing

[coral ingot]

If you ask in #type-hinting someone might know the reason behind why it was chosen to be like that

[cobalt plover]

yeah I tried using TypeAlias like https://mypy.readthedocs.io/en/stable/common_issues.html#variables-vs-type-aliases suggests but that doesn't seem to work

oh right I forgot there was a type specific chat, lemme ping this in there

[opal berry]

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