The thing that the author says they would prefer is already in Python, it's called NewType (https://docs.python.org/3/library/typing.html#typing.NewType)

They say "...so I can't create a bunch of different names for eg typing.Any and then expect type checkers to complain if I mix them."

`MyType = NewType('MyType', Any)`

is how you do this.

At the end, they suggest a workflow: "I think my ideal type hint situation would be if I could create distinct but otherwise unconstrained types for things like function arguments and function returns, have mypy or other typing tools complain when I mixed them, and then later go back to fill in the concrete implementation details of each type hint"

That's just doing the above, but then changing the `NewType('MyType', Any)` to something like `NewType('MyType', list[dict[str, int]])` later when you want to fill in the concrete implementation.

This is great, thank you for this. I've always wanted something that would complain if I passed Meters to something expecting Feet, but aliases didn't consider this an error.

mypy sadly doesn't accept 'NewType('MyType', Any)'; it complains 'error: Argument 2 to NewType(...) must be subclassable (got "Any") [valid-newtype]'. Possibly this is allowed by other Python type checkers. It is accepted at runtime, and I wish mypy allowed Any as a specific exemption to its checks.

(I'm the author of the linked-to article.)

Why is it that many of the examples for the "typing.protocal" class right below this involve meth??? Python WTF?