python装饰器

 1 import time
 2 def logger(fn):
 3     def wrap(*args,**kwargs):
 4         #before
 5         start=datetime.datetime.now()
 6         print("args={},kwargs={}".format(args,kwargs))#此行报错我却不知道
 7         ret=fn(*args,**kwargs)
 8         #after
 9         delta=(datetime.datetime.now()-start).total_seconds()
10         if delta>2:
11             print('dd')
12         else:
13             print("jj")
14         #print(ret)
15         return ret
16     return wrap
17 def show():
18     return 'super'
19 @logger    
20 def add(x,y):
21     time.sleep(3)
22     return x+y
23 
24 #wandou=logger(add) 也可以写add=logger(add)
25 print(add(4,6))

运行结果：

1 RESTART: C:/Users/Administrator/AppData/Local/Programs/Python/Python36/tryyyyy/zhuangshi.py 
2 args=(4, 6),kwargs={}
3 dd
4 10
5 >>>