python版本的策略模式

# -*- coding:UTF-8 -*-
import abc


class Strategy(metaclass=abc.ABCMeta):
    @abc.abstractmethod
    def algorithm_interface(self):
        pass


class ConcreteStrategyA(Strategy):
    def algorithm_interface(self):
        print(‘算法A实现‘)


class ConcreteStrategyB(Strategy):
    def algorithm_interface(self):
        print(‘算法B实现‘)


class ConcreteStrategyC(Strategy):
    def algorithm_interface(self):
        print(‘算法C实现‘)


class Context:
    def __init__(self,strategy):
        self.strategy=strategy

    def context_interface(self):
        self.strategy.algorithm_interface()


if __name__=="__main__":
    context = Context(ConcreteStrategyA())
    context.context_interface()
    context = Context(ConcreteStrategyB())
    context.context_interface()
    context = Context(ConcreteStrategyC())
    context.context_interface()