49 lines
1.1 KiB
Python
49 lines
1.1 KiB
Python
"""
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实例：
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一个任务状态机
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"""
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from abc import ABC, abstractmethod
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class Task:
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state: 'State'
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def __init__(self):
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self.set_state(PendingState())
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def set_state(self, state: 'State'):
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self.state = state
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def handle(self):
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self.state.handle(self)
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# 状态接口
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class State(ABC):
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@abstractmethod
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def handle(self, context):
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pass
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# 具体状态 - 待处理
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class PendingState(State):
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def handle(self, context):
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print("任务待处理，开始处理任务...")
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context.set_state(InProgressState())
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# 具体状态 - 处理中
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class InProgressState(State):
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def handle(self, context):
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print("任务处理中，完成任务...")
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context.set_state(CompletedState())
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# 具体状态 - 已完成
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class CompletedState(State):
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def handle(self, context):
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print("任务已完成，无法再处理。")
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if __name__ == "__main__":
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print("============= 状态模式 =============")
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task = Task()
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task.handle()
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task.handle()
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task.handle()
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print("\n=========== 状态模式结束 ===========") |