Lib/atexit.py

   1 """
   2 atexit.py - allow programmer to define multiple exit functions to be executed
   3 upon normal program termination.
   4
   5 One public function, register, is defined.
   6 """
   7
   8 __all__ = ["register"]
   9
  10 import sys
  11
  12 _exithandlers = []
  13 def _run_exitfuncs():
  14     """run any registered exit functions
  15
  16     _exithandlers is traversed in reverse order so functions are executed
  17     last in, first out.
  18     """
  19
  20     exc_info = None
  21     while _exithandlers:
  22         func, targs, kargs = _exithandlers.pop()
  23         try:
  24             func(*targs, **kargs)
  25         except SystemExit:
  26             exc_info = sys.exc_info()
  27         except:
  28             import traceback
  29             print >> sys.stderr, "Error in atexit._run_exitfuncs:"
  30             traceback.print_exc()
  31             exc_info = sys.exc_info()
  32
  33     if exc_info is not None:
  34         raise exc_info[0], exc_info[1], exc_info[2]
  35
  36
  37 def register(func, *targs, **kargs):
  38     """register a function to be executed upon normal program termination
  39
  40     func - function to be called at exit
  41     targs - optional arguments to pass to func
  42     kargs - optional keyword arguments to pass to func
  43
  44     func is returned to facilitate usage as a decorator.
  45     """
  46     _exithandlers.append((func, targs, kargs))
  47     return func
  48
  49 if hasattr(sys, "exitfunc"):
  50     # Assume it's another registered exit function - append it to our list
  51     register(sys.exitfunc)
  52 sys.exitfunc = _run_exitfuncs
  53
  54 if __name__ == "__main__":
  55     def x1():
  56         print "running x1"
  57     def x2(n):
  58         print "running x2(%r)" % (n,)
  59     def x3(n, kwd=None):
  60         print "running x3(%r, kwd=%r)" % (n, kwd)
  61
  62     register(x1)
  63     register(x2, 12)
  64     register(x3, 5, "bar")
  65     register(x3, "no kwd args")