python--decorators (two different usage scenarios)

Tag:__name__   ret   error       ...    orm   for   false    support    

#例子, add validation function to Show_name () function by adorner #version 1  #普通函数不带参数, adorner with parameter Def auth (func):     # print (func.__name__)   #通过打印这个结果得知, Show_name function was passed in     def auth_decorator ( USER, PWD):        u =  "Toby"          p =  "1qaz#edc"         if user  == u:            if pwd ==  p:                print ( "Auth done ...")                  func ()   #所以形式参数func等价于show_name ()              else:                 Print ("password Error ")         else:             print ("Not found user")     return auth_ Decorator@authdef show_name ():     print ("My name is toby") Show_name (" Toby "," 1qaz#edc ") # ###################################################################################### # # # #version  2  common functions and adorners with parametric Def auth (func):     # print (func.__name__)   #通过打印这个结果得知, the Show_name function was passed in     def auth_decorator (NAME, USER, PWD):         u =  "Toby"          p =  "1qaz#edc"         if user == u:             if pwd == p:        &Nbsp;        print ("Auth done ...")                  func (name)   #所以形式参数func等价于show_name ()             else:                 print ("Password error")          else:             print ("Not found user")     return auth_decorator@authdef show_ Name:     print ("my name is {0}". Format (name)) Show_name ("TTR",  " Toby "," 1qaz#edc ") #此时就要把show_name函数看成是show_name (NAME, USER, PWD) So, pass three parameters in # #################### ##################################################################### #version  3  The syntax used below, Allows dynamic creation of a decorated function object Def auth (func): &NBSp;   # print (func.__name__)   #通过打印这个结果得知, Show_name function was passed in     def  auth_decorator (USER, PWD):        u =  "Toby"         p =  "1qaz#edc"          if user == u:             if pwd == p:                 print ("Auth done ...")                  func ()   #所以形式参数func等价于show_name ()              else:                 print ("Password error")         else :              print ("Not found user")     return  auth_decoratordef show_name ():     print ("My name is juck") # In this function with the auth_enable parameter to control whether to decorate the Show_name function #auth_enable parameter is true, you must provide the user and pwd# is said to be open authentication and shutdown verification by Auth_enable to decide def  Show_name_strengthen (auth_enable=false, u=none, p=none ):     if auth_ Enable:        s = auth (Show_name)          s (u, p)     else:         show_name () #show_name_strengthen () Show_name_strengthen (true,  "Toby",  "1qaz#edc") ' two different grammars, Use the scene:     1, syntax with the @ symbol to use the adorner, this syntax is often used to make a permanent change to different functions     2, This syntax allows us to dynamically create a decorated function object, such as an adorner with several different functions,     introducing a judging condition to use a different adorner, which means that multiple optional behaviors can be supported.

python--decorators (two different usage scenarios)