Use `_PyArg_NoKeywords` instead of `_PyArg_NoKwnames` when checking the `kwds` tuple when creating `GenericAlias`. This fixes an interpreter crash when passing in keyword arguments to `GenericAlias`'s constructor.
Needs backport to 3.9.
Automerge-Triggered-By: GH:gvanrossum
This implements things like `list[int]`,
which returns an object of type `types.GenericAlias`.
This object mostly acts as a proxy for `list`,
but has attributes `__origin__` and `__args__`
that allow recovering the parts (with values `list` and `(int,)`.
There is also an approximate notion of type variables;
e.g. `list[T]` has a `__parameters__` attribute equal to `(T,)`.
Type variables are objects of type `typing.TypeVar`.
kj
Mikhail Golubev
Batuhan Taskaya
Victor Stinner
Hai Shi
Serhiy Storchaka
Dong-hee Na
Guido van Rossum