atexit
— 退出处理程序
¶
2.0 版新增。
源代码： Lib/atexit.py
The
atexit
module defines a single function to register cleanup functions. Functions thus registered are automatically executed upon normal interpreter termination.
atexit
运行这些函数按
reverse
次序当注册它们时；若注册
A
,
B
，和
C
，解释器终止时，运行它们将按次序
C
,
B
,
A
.
注意：
The functions registered via this module are not called when the program is killed by a signal not handled by Python, when a Python fatal internal error is detected, or when
os._exit()
被调用。
This is an alternate interface to the functionality provided by the
sys.exitfunc()
变量。
Note: This module is unlikely to work correctly when used with other code that sets
sys.exitfunc
. In particular, other core Python modules are free to use
atexit
without the programmer’s knowledge. Authors who use
sys.exitfunc
should convert their code to use
atexit
instead. The simplest way to convert code that sets
sys.exitfunc
is to import
atexit
and register the function that had been bound to
sys.exitfunc
.
atexit.
register
(
func
[
,
*args
[
,
**kwargs
]
]
)
¶
注册
func
as a function to be executed at termination. Any optional arguments that are to be passed to
func
must be passed as arguments to
register()
. It is possible to register the same function and arguments more than once.
At normal program termination (for instance, if
sys.exit()
is called or the main module’s execution completes), all functions registered are called in last in, first out order. The assumption is that lower level modules will normally be imported before higher level modules and thus must be cleaned up later.
If an exception is raised during execution of the exit handlers, a traceback is printed (unless
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.
2.6 版改变： This function now returns func ，从而可将其用作装饰器。
另请参阅
atexit
范例
¶
以下简单范例演示导入模块时如何从文件初始化计数器，并在程序终止时自动保存计数器更新值 (终止时不依赖应用程序对此模块做出的明确调用)。
try: _count = int(open("counter").read()) except IOError: _count = 0 def incrcounter(n): global _count _count = _count + n def savecounter(): open("counter", "w").write("%d" % _count) import atexit atexit.register(savecounter)
也可以把位置和关键词自变量传递给
register()
以沿注册函数传递当调用时：
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')
用作 装饰器 :
import atexit @atexit.register def goodbye(): print "You are now leaving the Python sector."
这仅适用于可不带自变量调用的函数。