import random


class 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 classes

class 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)