Weird, but legal ** syntax not accepted

[warsaw]

I saw this in real code, although I don't really understand the reason why this is done. Still, even though it's a bit weird, it's legal and I think mypy should allow it:

class Foo:
    def __init__(self, a=1, b=2):
        self.a = a
        self.b = b


Foo(**{})

$ mypy foo.py
foo.py:7: error: Keywords must be strings

[gvanrossum]

Agreed -- the dict could be type-checked here with a context of Mapping[str, Any] and that would make the empty dict have the type Dict[str, Any] rather than Dict[<nothing>, <nothing>].

Low priority though.