Click on singleton.py to get source.
class Singleton(object):
    __instance = None

    def __new__(cls, *args, **kwargs):
        if cls.__instance is None:
            cls.__instance = object.__new__(cls)
        return cls.__instance


class ExampleSingleton(Singleton):
    pass


x = ExampleSingleton()
y = ExampleSingleton()
print(x is y)