from abc import ABC, abstractmethod


class CarFactory(ABC):
    @abstractmethod
    def create_car(self):
        ...


class FordFactory(CarFactory):
    def create_car(self):
        pass


class SingletonMeta(type):
    _instances = {}

    def __call__(cls, *args, **kwargs):
        if cls not in cls._instances:
            instance = super().__call__(*args, **kwargs)
            cls._instances[cls] = instance

        return cls._instances[cls]


class FordFactorySingleton(FordFactory, metaclass=SingletonMeta):
    cars_made = 0

    def create_car(self):
        self.cars_made += 1


if __name__ == "__main__":
    ford_factory = FordFactorySingleton()
    ford_factory.create_car()

    print(f'ford_factory instance made {ford_factory.cars_made} cars')

    ford_factory2 = FordFactorySingleton()
    ford_factory2.create_car()

    print(f'ford_factory2 instance made {ford_factory2.cars_made} cars')

    print(f'Are they the same objects? {id(ford_factory) == id(ford_factory2)}')