python實現策略模式

策略模式如圖所示：

代碼如下：
#!/usr/bin/env python
# -*- coding:utf-8 -*-

class Strategy:
    "抽象算法類"

    def algorithmInterface(self):
        "抽象方法"
        pass

class ConcreteStrategyA(Strategy):
    "具體算法類A"

    def algorithmInterface(self):
        "具體實現方法"

        print('Algorithm A')


class ConcreteStrategyB(Strategy):
    "具體算法類A"

    def algorithmInterface(self):
        "具體實現方法"

        print('Algorithm B')


class ConcreteStrategyC(Strategy):
    "具體算法類A"

    def algorithmInterface(self):
        "具體實現方法"

        print('Algorithm C')

class Context:
    "上下文類"

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

    def contextInterface(self):
        "上下文接口"

        self.strategy.algorithmInterface()

if __name__ == '__main__':
    "相同調用方法不同策略"

    context = Context(ConcreteStrategyA())
    context.contextInterface()

    context = Context(ConcreteStrategyB())
    context.contextInterface()

    context = Context(ConcreteStrategyC())
    context.contextInterface()

學習轉載於：www.pythonfan.org