Since the usage of isinstance could be "isinstance(1, (int, float))", I'm wondering why it doesn't accept "[int, float]", if I do so, it would raise TypeError saying "arg 2 must be a type or tuple of types". What's the difference in effect between a tuple and a list here? (I know a tuple is immutable, but I think it doesn't matter when passing some other types of non-string iterables(yielding strings), am I right?