Types from the typing module that don't exist in the specified Python version are not detected by Mypy

[matthewslouismarie]

Hello there,

I think this is not the desired behaviour of Mypy. If I set the version of Python to 3.5, it doesn't report Deque imports, even though this type only appeared in Python 3.6.

mypy.ini:

[mypy]
python_version = 3.5

The python code:

from typing import Deque

...

This does not report any errors with mypy 0.670.

[gvanrossum]

Thanks for reporting! But it's not a flaw in mypy itself, it's in typeshed, which has a separate repo: https://github.com/python/typeshed. Please report it there!

[ilevkivskyi]

These type aliases (Deque etc) are added dynamically by mypy for subtle reasons, so this can't be fixed in typeshed. I think we can track this as part of #3413 (although it is not the same issue, the two should be probably fixed together).

[gvanrossum]

OK, reopening.

[AlexWaygood]

Python 3.5 is no longer supported by mypy, and I can't reproduce this with any other aliases, so I'm closing this.