Cc. @davidfstr

This could break users who want to use generic TypedDicts compatible with pre-3.11:

if TYPE_CHECKING:
    class TD(TypedDict, Generic[T]):
        a: T
else:
    class TD(TypedDict):
        a: T

d: TD[int] = {"a": 1}

I think it's safer to keep things unchanged here.

I think it's safer to keep things unchanged here.

Agreed.

Also, this PR appears to conflict with #27663 , which seems likely to be merged soon.

Forbidding parametrization of non-generic TypedDict types is a side effect of #27663. I created a separate issue to make it clear.

If we agree that it should forbidden, we should merge this PR (which also includes tests). If we agree that it should be allowed, we should add other tests, explicitly document this behavior, and change #27663 to keep non-generic TypedDict types parametrizable.

This could break users who want to use generic TypedDicts compatible with pre-3.11:

Why not write if TYPE_CHECKING or sys.version_info >= (3, 11):?

This could break users who want to use generic TypedDicts compatible with pre-3.11:

Why not write if TYPE_CHECKING or sys.version_info >= (3, 11):?

That would work, but it would be a backward compatibility break. We should let code work on 3.11 unchanged if possible.

When you're done making the requested changes, leave the comment: I have made the requested changes; please review again.

And if you don't make the requested changes, you will be poked with soft cushions!

Closing in favor of #92176.