Function _call_with_optional_argument

src/_pytest/python.py:760–769

Call the given function with the given argument if func accepts one argument, otherwise calls func without arguments.

(func, arg)

def _call_with_optional_argument(func, arg) -> None:
    """Call the given function with the given argument if func accepts one argument, otherwise
    calls func without arguments."""
    arg_count = func.__code__.co_argcount
    if inspect.ismethod(func):
        arg_count -= 1
    if arg_count:
        func(arg)
    else:
        func()


def _get_first_non_fixture_func(obj: object, names: Iterable[str]) -> Optional[object]: