Add type for variable-length, uniform tuples about typing HOT 4 CLOSED

This is decided and written up in the PEP: the syntax is Tuple[t1, ...] (the ... are a literal ellipsis).

from typing.

It was pointed out on python-ideas that the language about this in the PEP is somewhat ambiguous, e.g. Tuple[t1, ..., t2] or Tuple[..., t1] should be clearly ruled out. (And the language currently clearly allows Tuple[t1, t2, ...] which I think should be ruled out too.)

from typing.

Also, does the empty tuple match Tuple[int, ...]?

I think it should; just like [] matches List[int].

from typing.

I think an empty tuple should match Tuple[int, ...].

from typing.