@log的decorator完美实现（原创）

 # -*- coding: utf-8 -*-

 from functools import wraps
 from inspect import isfunction

 def beforecalled(*args, **kwargs):
     print('before called! {}'.format(len(args)))

     for arg in args:
         print(arg)        

 def aftercalled(*args, **kwargs):
     print('after called! {}'.format(len(args)))
     for k,v in kwargs.iteritems():
         print('{0}={1}'.format(k,v))

     jclist=['-' for _ in xrange(20)]
     print(''.join(jclist))

 def logdeco(*decoargs, **decokwargs):
     def decotator(func):
         @wraps(func)
         def wrapper(*funcargs, **funckwargs):
             beforecalled(*decoargs, **decokwargs)
             result = func(*funcargs, **funckwargs)
             aftercalled(*decoargs, **decokwargs)
             return result
         return wrapper
     return decotator

 def log(*decoargs, **decokwargs):
     if len(decoargs)==1 and len(decokwargs)==0:
         if isfunction(decoargs[0]) or hasattr(decoargs[0],'__call__'):
             return logdeco()(decoargs[0])

     def wrappered(func):
         return logdeco(*decoargs, **decokwargs)(func)

     return wrappered

 @log('lisa',50,email='[e-mail]')
 def testmoreparas(x,y):
     print('x*y={}'.format(x*y))

 @log()
 def testemptypara(x,y):
     print('x*y={}'.format(x*y))

 @log
 def testjustlog(x,y):
     print('x*y={}'.format(x*y))    

 if __name__=='__main__':
     testmoreparas(5,6)
     testemptypara(4,5)
     testjustlog(3,4)

 Python 2.7.15 (v2.7.15:ca079a3ea3, Apr 30 2018, 16:22:17) [MSC v.1500 32 bit (Intel)] on win32
 Type "copyright", "credits" or "license()" for more information.
 >>>
 ============ RESTART: D:\pytest\logdecorator.py ============
 before called! 2
 lisa
 50
 x*y=30
 after called! 2
 email=[e-mail]
 --------------------
 before called! 0
 x*y=20
 after called! 0
 --------------------
 before called! 0
 x*y=12
 after called! 0
 --------------------
 >>> 

test result