抽象工厂模式

# -*- coding: utf-8 -*-
# http://ginstrom.com/scribbles/2007/10/08/design-patterns-python-style/
"""Implementation of the abstract factory pattern"""
import random
class :
    """A pet shop"""
    def __init__(self, animal_factory=None):
        self.factory = animal_factory
    def show_pet(self):
        """Creates and shows a pet using the abstract factory"""
        pet = self.factory.get_pet()
        print('We have a lovely {}'.format(pet))
        print('It says {}'.format(pet.speak()))
        print('We also have {}'.format(self.pet_factory.get_food()))
class Dog:
    
    def speak(self):
        print 'woof'
    def __str__(self):
        return 'Dog'
class Cat:
    
    def speak(self):
        print 'meow'
    def __str__(self):
        return 'Cat'
class DogFactory:
    
    def get_pet(self):
        return Dog()
    def get_food(self):
        return 'dog food'
class CatFactory:
    
    def get_pet(self):
        return Cat()
    def get_food(self):
        return 'cat food'
def get_factory():
    """Let's by dynamic!"""
    return random.choice([DogFactory, CatFactory])
if __name__ == '__main__':
    for i in range(3):
        shop = PetShot(get_factory())
        shop.show_pet()
        print('=' * 20)
### OUTPUT ###
# We have a lovely Dog
# It says woof
# We also have dog food
# ====================
# We have a lovely Dog
# It says woof
# We also have dog food
# ====================
# We have a lovely Cat
# It says meow
# We also have cat food
# ====================