抽象工厂模式

import os
import abc
import six

class Animal(six.with_metaclass(abc.ABCMeta, object)):
    """ clients only need to know this interface for animals"""
    @abc.abstractmethod
    def sound(self, ):
        pass


class AnimalFactory(six.with_metaclass(abc.ABCMeta, object)):
    """clients only need to know this interface for creating animals"""
    @abc.abstractmethod
    def create_animal(self,name):
        pass


class Dog(Animal):
    def __init__(self, name):
        self.name = name
    def sound(self, ):
        print("bark bark")


class DogFactory(AnimalFactory):
    def create_animal(self,name):
        return Dog(name)


class Cat(Animal):
    def __init__(self, name):
        self.name = name
    def sound(self, ):
        print("meow meow")


class CatFactory(AnimalFactory):
    def create_animal(self,name):
        return Cat(name)


class Animals(object):
    def __init__(self,factory):
        self.factory = factory
    def create_animal(self, name):
        return self.factory.create_animal(name)


if __name__ == '__main__':
    atype = raw_input("what animal (cat/dog) ?").lower()
    if atype == 'cat':
        animals = Animals(CatFactory())
    elif atype == 'dog':
        animals = Animals(DogFactory())
    a = animals.create_animal('bulli')
    a.sound()