Singleton implementation in Python

python_singleton.py

class SingletonMeta(type):

    _instance = None

    def __call__(self):
        if self._instance is None:
            self._instance = super().__call__()
        return self._instance


class Singleton(metaclass=SingletonMeta):
    # Now implement you singleton class
    def some_business_logic(self):
        pass


if __name__ == "__main__":

    s1 = Singleton()
    s2 = Singleton()

    # You can check they are both same instance
    assert(id(s1) == id(s2))