python装饰器的用法

def logger(func):

   def inner(*args, **kwargs): #1

        print "Arguments were: %s, %s" % (args, kwargs)

        return func(*args, **kwargs) #2

  return inner

 

>>> @logger

... def foo1(x, y=1):

...     return x * y

>>> @logger

... def foo2():

...     return 2

>>> foo1(5, 4)

Arguments were: (5, 4), {}

20

>>> foo1(1)

Arguments were: (1,), {}

1

>>> foo2()

Arguments were: (), {}

2