python設計模式第九天【策略模式】

標籤：str   method   imp   平滑   ace   bubuko   object   pytho   模式   

1. 定義

對一系列演算法進行封裝，為所有演算法定義一個抽象的演算法介面，可以平滑的進行演算法切換

 

2. 策略模式的UML圖

 

3.代碼實現

#!/usr/bin/env python#! _*_ coding:UTF-8 _*_from abc import ABCMeta, abstractmethodclass Context(object):    def setStrategy(self, strategy):        self.__strategy = strategy    def operation(self):        self.__strategy.algorithmInterface()class Strategy(object):    @abstractmethod    def algorithmInterface(self):        passclass ConcreteStrategyA(Strategy):    def algorithmInterface(self):        print "strategy A"class ConcreteStrategyB(Strategy):    def algorithmInterface(self):        print "strategy B"if __name__ == "__main__":    context = Context()    concreteStrategyA = ConcreteStrategyA()    concreteStrategyB = ConcreteStrategyB()    context.setStrategy(concreteStrategyA)    context.operation()    context.setStrategy(concreteStrategyB)    context.operation()

結果：

/Users/liudaoqiang/PycharmProjects/numpy/venv/bin/python /Users/liudaoqiang/Project/python_project/day09_strategy/strategy_test.pystrategy Astrategy BProcess finished with exit code 0

 

python設計模式第九天【策略模式】