[python] How to "test" NoneType in python?

It can also be done with isinstance as per Alex Hall's answer :

>>> NoneType = type(None)
>>> x = None
>>> type(x) == NoneType
True
>>> isinstance(x, NoneType)
True

isinstance is also intuitive but there is the complication that it requires the line

NoneType = type(None)

which isn't needed for types like int and float.