🔒 Mypy: Overloaded function signatures 1 and 2 overlap with incompatible return types

[kind sapphire]

I have a function that will return a single response as an int if the count passed to the function is 1. Elsewise, a list of responses is returned.

I tried to type this using overloads, however I get an error from MyPy: Overloaded function signatures 1 and 2 overlap with incompatible return types [overload-overlap]

I've researched, and it seems like the problem is that a count of 1 would satisfy both overloads, which is not allowed.

Does anyone know how to get around this?

@overload
def read_and_check(self, address: int, count: Literal[1] = 1) -> int: ...

@overload
def read_and_check(self, address: int, count: int) -> list[int]: ...

[sour pine]

@kind sapphire

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[zinc peak]

have you made the actual implementation?

    @overload
    def read_and_check(self, address: int, count: Literal[1] = 1) -> int: ...
    @overload
    def read_and_check(self, address: int, count: int) -> list[int]: ...
    def read_and_check(self, address: int, count: int = 1):
        """actual implementation"""
        ...

[kind sapphire]

Yes, just forgot to put it here...

Here is a working example:

from typing import Literal, overload


@overload
def read_and_check(address: int, count: Literal[1] = 1) -> int: ...


@overload
def read_and_check(address: int, count: int) -> list[int]: ...


def read_and_check(address: int, count: int = 1) -> int | list[int]:
    """actual implementation"""
    if count == 1:
        return 1
    else:
        return [1, 2, 3]

Curiously, this is fine with Pyright

But MyPy gives the same error.

[sour pine]

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