工厂方法模式
定义一个用于创建对象的接口(工厂接口),让子类决定实例化哪一个产品类
from abc import ABCMeta, abstractmethod
# 抽象产品角色(Product)
class Payment(metaclass=ABCMeta):
@abstractmethod
def pay(self, money):
pass
# 具体产品角色(Concrete Product)
class AliPay(Payment):
def __init__(self, use_huabei=False):
self.use_huabei = use_huabei
def pay(self, money):
if self.use_huabei:
print('花呗支付%d元' % money)
else:
print('支付宝余额支付%d元' % money)
# 具体产品角色(Concrete Product)
class WechatPay(Payment):
def pay(self, money):
print('微信支付%d元' % money)
class BankPay(Payment):
def pay(self, money):
print('银行卡支付%d元' % money)
# 抽象工厂角色(Creator)
class PaymentFactory(metaclass=ABCMeta):
@abstractmethod
def create_payment(self):
pass
# 具体工厂角色(Concrete Creator)
class AlipayFactory(PaymentFactory):
def create_payment(self):
return AliPay()
class WechatFactory(PaymentFactory):
def create_payment(self):
return WechatPay()
class BankFactory(PaymentFactory):
def create_payment(self):
return BankPay()
ali_factory = AlipayFactory()
p1 = ali_factory.create_payment()
p1.pay(1000)
we_factory = WechatFactory()
p2 = we_factory.create_payment()
p2.pay(2000)
bank_factory = BankFactory()
p3 = bank_factory.create_payment()
p3.pay(3000)
优点
每个具体产品都对应一个具体工厂类,不需要修改原有工厂类代码
隐藏了对象创建的实现细节
缺点
每增加一个具体产品类,就必须增加一个相应的具体工厂类
Last updated