Python atexit模块

atexit模块介绍

作用：让注册的函数在解释器正常终止时自动执行，可以注册多个函数，所注册的函数会逆序执行（据查资料，造成逆序的原因为函数压栈造成的，先进后出）

1、正常注册 ，示例如下。

def goodbye(name, adjective):
    print("Goodbye %s, it was %s to meet you."% (name, adjective))

def hello():
    print('hello world!')

def a():
    print('a')

import atexit
atexit.register(goodbye, 'Donny', 'nice')
atexit.register(a)
hello()
# 输出
PS E:\Atom\files\app> python .\ex9_atexit.py
hello world!
a
Goodbye Donny, it was nice to meet you.

2、可以使用装饰器来注册，但是只适用于没有参数时调用。

import atexit

@atexit.register
def hello():
    print('Hello world!')

# 输出
PS E:\Atom\files\app> python .\ex9_atexit.py
Hello world!

3、取消注册， 示例如下。

def goodbye(name, adjective):
    print("Goodbye %s, it was %s to meet you."% (name, adjective))

def hello():
    print('hello world!')

def a():
    print('a')

import atexit
atexit.register(goodbye, 'Donny', 'nice')
atexit.register(a)
atexit.register(a)
atexit.register(a)
hello()
atexit.unregister(a)
# 输出
PS E:\Atom\files\app> python .\ex9_atexit.py
hello world!
Goodbye Donny, it was nice to meet you.

这个模块一般用来在程序结束时，做资源清理。