Python设计模式之抽象工厂模式

import randomclass PetShop:  """宠物商店"""  def __init__(self, animal_factory=None):    """宠物工厂是我们的抽象工厂。我们可以随意设置。"""     self.pet_factory = animal_factory  def show_pet(self):    """使用抽象工厂创建并显示一个宠物"""    pet = self.pet_factory.get_pet()    print("我们有一个可爱的 {}".format(pet))    print("它说 {}".format(pet.speak()))    print("我们还有 {}".format(self.pet_factory.get_food()))# 工厂生产的事物class Dog:  def speak(self):    return "汪"  def __str__(self):    return "Dog"class Cat:  def speak(self):    return "喵"  def __str__(self):    return "Cat"# Factory classesclass DogFactory:  def get_pet(self):    return Dog()  def get_food(self):    return "狗食"class CatFactory:  def get_pet(self):    return Cat()  def get_food(self):    return "猫粮"# 随机创建合适的工厂def get_factory():  """让我们动起来！"""  return random.choice([DogFactory, CatFactory])()# 多个工厂显示宠物if __name__ == "__main__":  for i in range(4):    shop = PetShop(get_factory())    shop.show_pet()    print("=" * 20)