43 lines
1019 B
Python
43 lines
1019 B
Python
"""
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实例：
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汤宝宝成为了收银员，消费者可以使用现金或者支付宝支付。
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"""
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from abc import ABC, abstractmethod
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class Strategy(ABC):
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@abstractmethod
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def pay(self, amount: float) -> str:
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pass
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class CashPayment(Strategy):
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def pay(self, amount: float) -> str:
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return(f"使用现金支付了 {amount:.2f} 元。")
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class AlipayPayment(Strategy):
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def pay(self, amount: float) -> str:
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return(f"使用支付宝支付了 {amount:.2f} 元。")
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class Context:
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strategy: Strategy
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def set_strategy(self, strategy: Strategy) -> None:
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self._strategy = strategy
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def pay(self, amount: float) -> str:
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return self._strategy.pay(amount)
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if __name__ == "__main__":
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print("=========== 策略模式 ===========")
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context = Context()
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context.set_strategy(CashPayment())
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print(context.pay(100.0))
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context.set_strategy(AlipayPayment())
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print(context.pay(200.0))
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print("\n========= 策略模式结束 =========") |