### 导航 - [索引](../genindex.xhtml "总目录") - [模块](../py-modindex.xhtml "Python 模块索引") | - [下一页](traceback.xhtml "traceback --- Print or retrieve a stack traceback") | - [上一页](abc.xhtml "abc --- 抽象基类") | -  - [Python](https://www.python.org/) » - zh\_CN 3.7.3 [文档](../index.xhtml) » - [Python 标准库](index.xhtml) » - [Python运行时服务](python.xhtml) » - $('.inline-search').show(0); | # [`atexit`](#module-atexit "atexit: Register and execute cleanup functions.") --- 退出处理器 - - - - - - [`atexit`](#module-atexit "atexit: Register and execute cleanup functions.") 模块定义了清理函数的注册和反注册函数. 被注册的函数会在解释器正常终止时执行. [`atexit`](#module-atexit "atexit: Register and execute cleanup functions.") 会按照注册顺序的\*逆序\*执行; 如果你注册了 `A`, `B` 和 `C`, 那么在解释器终止时会依序执行 `C`, `B`, `A`. **注意:** 通过该模块注册的函数, 在程序被未被 Python 捕获的信号杀死时并不会执行, 在检测到 Python 内部致命错误以及调用了 [`os._exit()`](os.xhtml#os._exit "os._exit") 时也不会执行. 在 3.7 版更改: When used with C-API subinterpreters, registered functions are local to the interpreter they were registered in. `atexit.``register`(*func*, *\*args*, *\*\*kwargs*)将 *func* 注册为终止时执行的函数. 任何传给 *func* 的可选的参数都应当作为参数传给 [`register()`](#atexit.register "atexit.register"). 可以多次注册同样的函数及参数. 在正常的程序终止时 (举例来说, 当调用了 [`sys.exit()`](sys.xhtml#sys.exit "sys.exit") 或是主模块的执行完成时), 所有注册过的函数都会以后进先出的顺序执行. 这样做是假定更底层的模块通常会比高层模块更早引入, 因此需要更晚清理. If an exception is raised during execution of the exit handlers, a traceback is printed (unless [`SystemExit`](exceptions.xhtml#SystemExit "SystemExit") is raised) and the exception information is saved. After all exit handlers have had a chance to run the last exception to be raised is re-raised. 这个函数返回 *func* 对象，可以把它当作装饰器使用。 `atexit.``unregister`(*func*)Remove *func* from the list of functions to be run at interpreter shutdown. After calling [`unregister()`](#atexit.unregister "atexit.unregister"), *func* is guaranteed not to be called when the interpreter shuts down, even if it was registered more than once. [`unregister()`](#atexit.unregister "atexit.unregister") silently does nothing if *func* was not previously registered. 参见 模块 [`readline`](readline.xhtml#module-readline "readline: GNU readline support for Python. (Unix)")使用 [`atexit`](#module-atexit "atexit: Register and execute cleanup functions.") 读写 [`readline`](readline.xhtml#module-readline "readline: GNU readline support for Python. (Unix)") 历史文件的有用的例子。 ## [`atexit`](#module-atexit "atexit: Register and execute cleanup functions.") 示例 The following simple example demonstrates how a module can initialize a counter from a file when it is imported and save the counter's updated value automatically when the program terminates without relying on the application making an explicit call into this module at termination. ``` try: with open("counterfile") as infile: _count = int(infile.read()) except FileNotFoundError: _count = 0 def incrcounter(n): global _count _count = _count + n def savecounter(): with open("counterfile", "w") as outfile: outfile.write("%d" % _count) import atexit atexit.register(savecounter) ``` Positional and keyword arguments may also be passed to [`register()`](#atexit.register "atexit.register") to be passed along to the registered function when it is called: ``` def goodbye(name, adjective): print('Goodbye, %s, it was %s to meet you.' % (name, adjective)) import atexit atexit.register(goodbye, 'Donny', 'nice') # or: atexit.register(goodbye, adjective='nice', name='Donny') ``` 作为 [decorator](../glossary.xhtml#term-decorator): 使用: ``` import atexit @atexit.register def goodbye(): print("You are now leaving the Python sector.") ``` 只有在函数不需要任何参数调用时才能工作. ### 导航 - [索引](../genindex.xhtml "总目录") - [模块](../py-modindex.xhtml "Python 模块索引") | - [下一页](traceback.xhtml "traceback --- Print or retrieve a stack traceback") | - [上一页](abc.xhtml "abc --- 抽象基类") | -  - [Python](https://www.python.org/) » - zh\_CN 3.7.3 [文档](../index.xhtml) » - [Python 标准库](index.xhtml) » - [Python运行时服务](python.xhtml) » - $('.inline-search').show(0); | © [版权所有](../copyright.xhtml) 2001-2019, Python Software Foundation. Python 软件基金会是一个非盈利组织。 [请捐助。](https://www.python.org/psf/donations/) 最后更新于 5月 21, 2019. [发现了问题](../bugs.xhtml)？ 使用[Sphinx](http://sphinx.pocoo.org/)1.8.4 创建。