python C 线程类中__init__的相反
发布时间：2023-12-22 05:01:31 所属栏目：Python 来源：DaWei
导读： 我知道当你创建像newThread = MyThread(property)这样的类并且newthread.start()触发run()时会自动调用__init __().我正在寻找的是在线程终止之前自动调用的东西,所以我不必在每个return语句
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我知道当你创建像newThread = MyThread(property)这样的类并且newthread.start()触发run()时会自动调用__init __().我正在寻找的是在线程终止之前自动调用的东西,所以我不必在每个return语句之前显式调用self.cleanUp(). class MyThread(Thread): def __init__(self,property): Thread.__init__(self) self.property = property def cleanUp(self): # Clean up here def run(self): # Do some stuff self.cleanUp() # Current work around return 解决方法 一种方法是使Thread子类也为 context manager.这将有效地使__exit __()成为您想要触发的特殊方法. 以下显示了我的建议.注意：我重命名了您传递构造函数的属性参数,因为property是Python内置的名称. from threading import Thread import time TEST_THREAD_EXCEPTION = False # change as desired class MyThread(Thread): def __init__(self,attribute): Thread.__init__(self) self.attribute = attribute def cleanup(self): # Clean up here print(' cleaning up after thread') def run(self): if TEST_THREAD_EXCEPTION: raise RuntimeError('OOPS!') # force exception print(' other thread now running...') time.sleep(2) # Do something... def __enter__(self): try: self.run() except Exception as exc: print('Error: {} exception raised by thread'.format(exc)) raise # reraise the exception return self def __exit__(self,*args): self.cleanup() print('main thread begins execution') with MyThread('hello') as thread: print('doing other things in main thread while other thread is running') print('main thread continuing...')输出： main thread begins execution other thread now running... doing other things in main thread while other thread is running cleaning up after thread main thread continuing on...如果将TEST_THREAD_EXCEPTION更改为True,则不会调用cleanup(),因为线程未成功运行 C 尽管您可以根据需要更改它,但可能还需要确保它不会被调用两次.以下是上述代码在这种情况下的作用： main thread begins execution Error: OOPS! exception raised by thread Traceback (most recent call last): File "opposite_init.py",line 37,in <module> with MyThread('hello') as thread: File "opposite_init.py",line 27,in __enter__ self.run() File "opposite_init.py",line 21,in run raise RuntimeError('OOPS!') # force exception RuntimeError: OOPS!（编辑：阜阳站长网） 【声明】本站内容均来自网络，其相关言论仅代表作者个人观点，不代表本站立场。若无意侵犯到您的权利，请及时与联系站长删除相关内容! |
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