Proper way to specify type annotation of a MapAttribute subclass?

[andrewli1030]

Supposed I define a MapAttribute subclass like follows:

class MyMapAttribute(MapAttribute):
    pass

When I run pre-commit's (rev 2.1.0) mypy hook (rev 0.701), I run into the following error:

error: Missing type parameters for generic type

I am using pynamodb==4.0.0.

[garrettheel]

This is happening because the disallow_any_generics is enabled in your mypy conf. The way we currently type MapAttributes is flawed due to it behaving differently depending on whether you subclass it or instantiate it directly. So basically this is a bug in our type information, but not easy to fix today.

@jpinner-lyft do you think it's worth creating a new issue to track the Model/MapAttribute changes that you had lined up?

[l0b0]

Do you have any hints on how to type result = MapAttribute(…)? Edit: Separate issue

[garrettheel]

@l0b0 would you mind creating a separate issue with more context?