Python atexit.register example

atexit.register.py

"""
atexit.register example

The atexit module defines a single function to register cleanup functions. 
Functions thus registered are automatically executed upon normal interpreter termination

https://docs.python.org/2/library/atexit.html
"""

# Caution: If you work with IDLE this example doesn't work

try:
    _count = int(open("c:\counter").read())
except IOError:
    _count = 0
 
def incrcounter(n):
    global _count
    _count = _count + n
 
def savecounter():
    open("c:\counter", "w").write("%d" % _count)
 
import atexit, sys
atexit.register(savecounter)
incrcounter(1)