Function complain

mypy/config_parser.py:65–68

(x: object, additional_info: str = "")

    If an element of the input is not str, a type error will be raised."""

    def complain(x: object, additional_info: str = "") -> Never:
        raise argparse.ArgumentTypeError(
            f"Expected a list or a stringified version thereof, but got: '{x}', of type {type(x).__name__}.{additional_info}"
        )

    if isinstance(v, str):
        items = [p.strip() for p in re.split(split_regex, v)]