python之装饰器

 1 #定义装饰器函数
 2 def W1(main_func):
 3     def outer():
 4         print("before")
 5         show()
 6         print("after")
 7     return outer
 8 
 9 #使用装饰器    
10 @W1
11 def show():
12     pass 
13 
14 #执行show方法    
15 show()

 1 #之前函数
 2 def Before(request,kargs):
 3     print ‘before‘
 4     
 5 #之后函数
 6 def After(request,kargs):
 7     print ‘after‘
 8   
 9 #装饰器函数  
10 def Filter(before_func,after_func):
11     def outer(main_func):
12         def wrapper(request,kargs):
13               
14             before_result = before_func(request,kargs)
15             if(before_result != None):
16                 return before_result;
17               
18             main_result = main_func(request,kargs)
19             if(main_result != None):
20                 return main_result;
21               
22             after_result = after_func(request,kargs)
23             if(after_result != None):
24                 return after_result;
25               
26         return wrapper
27     return outer
28 
29 #使用装饰器    
30 @Filter(Before, After)
31 def Index(request,kargs):
32     print ‘index‘