设计模式之策略模式

时间 2019-11-11

标签设计模式策略繁體版

原文原文链接

1. 公共接口：python

class MDCash:
    def acceptCash(self):
        return

2. 根据上面定义的接口实现：code

# 正常
class MDCashNormal(MDCash):
    def acceptCash(self, params):
        return params
# 返5
class MDCaseReturn(MDCash):
    def acceptCash(self, params):
        return params - 5
# 打9折
class MDCashRobate(MDCash):
    def acceptCash(self, params):
        return params - params * 0.1

3. 实现context，封装不一样行为的接口。orm

class MDCashContext:
    def __init__(self, cashStrategy):
        self.cashStrategy = cashStrategy
    def performPay(self, params):
        print self.cashStrategy.acceptCash(params)

4. 使用接口

if __name__ == '__main__':
    context = MDCashContext(cashStrategy=MDCaseReturn())
    context.performPay(100)

    context = MDCashContext(cashStrategy=MDCashNormal())
    context.performPay(100)

    context = MDCashContext(cashStrategy=MDCashRobate())
    context.performPay(100)

5. 全部代码：utf-8

#encoding:utf-8

class MDCash:
    def acceptCash(self):
        return

class MDCashNormal(MDCash):

    def acceptCash(self, params):
        return params

class MDCaseReturn(MDCash):
    def acceptCash(self, params):
        return params - 5

class MDCashRobate(MDCash):
    def acceptCash(self, params):
        return params - params * 0.1

class MDCashContext:
    def __init__(self, cashStrategy):
        self.cashStrategy = cashStrategy
    def performPay(self, params):
        print self.cashStrategy.acceptCash(params)

if __name__ == '__main__':
    context = MDCashContext(cashStrategy=MDCaseReturn())
    context.performPay(100)

    context = MDCashContext(cashStrategy=MDCashNormal())
    context.performPay(100)

    context = MDCashContext(cashStrategy=MDCashRobate())
    context.performPay(100)

运行结果：it

95
100
90.0