let T = TypeVar("T") in

class list(Generic[T]):

    def append(self, obj: T, /) -> None: ...

let T = TypeVar("T") in

let U = TypeVar("U") in

def two_tvars(x: T, y: U) -> T | U: ...

SimpleGenerator: TypeAlias = let T = TypeVar("T") in Generator[T, None, None]

def make_identity_func() -> let T = TypeVar("T") in Callable[[T], T]: ...

`let` would be a new soft keyword. The syntax would be available in all expressions and in class and def statements.

At runtime, the first example would be equivalent to something like:

T = TypeVar("T")

class list(Generic[T]):

del T

Advantages:

* Less new syntax, so it is easier to get into the language and easier to extend with new flavors of type variables that we may introduce in the future.

* The new syntax is potentially useful outside of typing.

* Allows a way to explicitly scope type variables to part of a type or to a type alias.

Disadvantages:

* Less elegant syntax for generic classes (the flipside of it being more general).

* Does not remove the redundancy in T = TypeVar("T")