Re: [Python-ideas] "Sum" Type hinting [was: Type hinting for path-related functions]

Koos Zevenhoven writes:

I just don't want to say I broke the type hinting for os.path.*

Blame it on Brett. :-)

But if I'm told Unions are sufficient,

Unions aren't. TypeVars are (and they're basically what you proposed as a solution, I just didn't recognize them in the context of "Union").

There is nothing suspicious about that Union there. "Union[str, bytes] -> str" is a perfectly good type hint for os.fsdecode. You can't get any more precise than that.

Unions are suspicious as *values*, not as arguments. Fortunately, AnyStr is not a Union.