Lowest common denominator of set and fronzenset?

[dimaqq]

How to type a function argument so that both set and frozenset can be passed?
I mean to make a promise to the function user that:

• function doesn't modify the argument
• function doesn't need it to be hashable

(To be fair this is really a form of "repeatable [unordered] iterable" for which there's no good type hint).

[erictraut]

I'm not sure I understand your question. Would a simple union type meet your needs?

def func(x: set[Any] | frozenset[Any]):
    pass

[dimaqq]

If that’s the best possible, sure, though it gets rather repetitive when parametrized.

[erictraut]

You can create a type alias to reduce repetition:

type MySet = set[Any] | frozenset[Any]

def func(x: MySet):
    pass

[Azureblade3808]

collections.abc.Set (also known as typing.AbstractSet) may suit your need.

from collections.abc import Set

def func(x: Set[int]): ...

func({0})
func(frozenset({0}))