工厂模式的python实现

#1.什么是工厂模式

#2.工厂模式的分类
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	1. 简单工厂模式
	2. 工厂方法模式
	3. 抽象工厂方法模式
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#3.简单工厂模式的python实现
from abc import ABCMeta, abstractmethod
class Animal(metaclass=ABCMeta):
	@abstractmethod
	def do_say(self):
		pass
	
class Dog(Animal):
	def do_say(self):
		print("wang wang!!")
	
class Cat(Animal):
	def do_say(self):
		print("miao miao!!")

## 定义工厂
class ForestFactory(object):
	def make_sound(self, object_type):
		return eval(object_type)().do_say()

## client code
if __name__ == "__main__":
	ff = ForestFactory()
	animal = input("Which animal should make_sound Dog or Cat?")
	ff.make_sound(animal)


#4.工厂方法模式的python实现
from abc import ABCMeta, abstractmethod
class Section(metaclass=ABCMeta):
	@abstractmethod
	def describe(self):
		pass

class PersonSection(Section):
	def describe(self):
		print("personal section")

class AlbumSection(Section):
	def describe(self):
		print("Album section")
		
class PatentSection(Section):
	def describe(self):
		print("Patent section")

class PublicationSection(Section):
	def describe(self):
		print("Publication section")

# 创建一个抽象类, 并提供一个工厂方法
class Profile(metaclass=ABCMeta):
	def __init__(self):
		self.sections = []
		self.createProfile()		

	@abstractmethod
	def createProfile(self):
		pass
	
	def getSections(self):
		return self.sections
	
	def addsections(self, section):
		self.sections.append(section)

class Zhihu(Profile):
	def createProfile(self):
		self.addsections(PersonSection())
		self.addsections(AlbumSection())
		self.addsections(PublicationSection())

class Csdn(Profile):
	def createProfile(self):
		self.addsections(PatentSection())
		self.addsections(PersonSection())

if __name__ == ‘__main__‘:
	profile_type = input("which profile you‘d like to create (Zhihu or Csdn)")
	profile = eval(profile_type)()
	print("create profile..", type(profile).__name__)
	print("Profile has sections --", profile.getSections())		
	

#5.抽象工厂模式的python实现
from abc import ABCMeta, abstractmethod


class PizzaFactory(metaclass=ABCMeta):
    
    @abstractmethod
    def createVegPizza(self):
        pass
    
    @abstractmethod
    def createNonVegPizza(self):
        pass

class IndianPizzaFactory(PizzaFactory):
    
    def createVegPizza(self):
        return DeluxVeggiePizza()
    def createNonVegPizza(self):
        return ChickenPizza()

class USPizzaFactory(PizzaFactory):
    
    def createVegPizza(self):
        return MexicanVegPizza()
    def createNonVegPizza(self):
        return HamPizza()

class VegPizza(metaclass=ABCMeta):
    
    @abstractmethod
    def prepare(self, VegPizza):
        pass

class NonVegPizza(metaclass=ABCMeta):
    
    @abstractmethod
    def serve(self, VegPizza):
        pass

class DeluxVeggiePizza(VegPizza):
    
    def prepare(self):
        print("Prepare ", type(self).__name__)

class ChickenPizza(NonVegPizza):
    
    def serve(self, VegPizza):
        print(type(self).__name__, " is served with Chicken on ", type(VegPizza).__name__)

class MexicanVegPizza(VegPizza):
    
    def prepare(self):
        print("Prepare ", type(self).__name__)

class HamPizza(NonVegPizza):
    
    def serve(self, VegPizza):
        print(type(self).__name__, " is served with Ham on ", type(VegPizza).__name__)

class PizzaStore:
    
    def __init__(self):
        pass
    
    def makePizzas(self):
        for factory in [IndianPizzaFactory(), USPizzaFactory()]:
            self.factory = factory
            self.NonVegPizza = self.factory.createNonVegPizza()
            self.VegPizza = self.factory.createVegPizza()
            self.VegPizza.prepare()
            self.NonVegPizza.serve(self.VegPizza)


pizza = PizzaStore()
pizza.makePizzas()

#6.工厂方法与抽象工厂方法的比较
# 工厂方法开发了一个创建对象的方法    
# 抽象工厂方法开放了一个或者多个方法创建一个系列的相关对象
# 工厂方法使用继承和子类来决定要创建哪个对象
# 抽象共产方法使用组合将创建对象的任务委托给其他类
# 共产方法用于创建一个产品
# 抽象工厂方法用于创建相关产品的系列
#
#7.工厂模式的优缺点
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	优点: 1.松耦合, 即对象的创建可以独立于类的实现
		  2.客户端无需了解创建对象的类的实现,但是依然可以创建对象
		  3.可以在工厂中添加其他类来创建其他类型的对象
		  4.工厂可以重用现有对象
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