Can we make AbstractContextManager.__exit__ concrete?

[NeilGirdhar]

@ajoino

say that changing the type to be a protocol would make the most sense here,

I agree that this would fix things, however there are some notable advantages to having base classes:

• runtime instance checking is faster,
• runtime instance checking is more precise, and
• intent to implement is clearly specified.

Personally, I think we should prefer base classes to protocols, but I understand your point.

@ajoino

There was a discussion about adding a “this method must be overridden but should not be considered abstract”-method decorator recently

That’s a very cool idea, and would be a fine solution to this.

@Daverball

There has been a discussion just recently how type checkers should treat this case: Calling abstract methods

Nice find! So my suggestion is the same as Guido’s I guess?

@Daverball

I think this is a bug in type checker behavior, not a problem with the implementation.

Okay, I guess my preference would be to remove this odd decoration. I don’t think we do it in any other similar place? I don’t think I’ve ever written a method that I decorated with @abstractmethod that didn’t also raise in its body.