def assert_is_not ( expected , actual , message = None , extra = None ) : assert expected is not actual , _assert_fail_message ( message , expected , actual , "is" , extra )
python assert not raised
Raises an AssertionError if expected is actual .
def assert_is_not(expected, actual, message=None, extra=None):
    """Raises an AssertionError if expected is actual."""
    assert expected is not actual, _assert_fail_message(
        message, expected, actual, "is", extra
    )