set() is an instance of typing.Sized

[mitar]

>>> import typing
>>> from pytypes import type_util
>>> type_util._isinstance(set(), typing.Sized)
False
>>> isinstance(set(), typing.Sized)
True

The first False is surprising. I would expect it to be True like isinstance is.

[Stewori]

Okay, like explained in #32 (comment), this is an issue with Empty. Currently pytypes only supports empty data structures w.r.t. Container. I'll think about how we can add support for Sized and Iterable (something else?)

[Stewori]

Fixed as of 5736ecd.
Todo: Tests.

[mitar]

I didn't realize that this is associated with there being an empty set.

Thanks again for quick solutions.