Python3 之裝飾器

標籤：cti   修改   調用   time()   time   span   strong   else   sleep   

裝飾器的作用：擴充函數功能。

特點：1.不修改原函數代碼

           2.保持調用函數不變

 

原理：高階函數 + 嵌套函數 = 裝飾器

 

 1 # Author = Johnston 2 import time 3 def timer(func): 4     def deco(): 5         start_time = time.time() 6         func() 7         end_time = time.time() 8         print("the function run time is %s" %(end_time-start_time)) 9     return deco10 11 @timer  #bar = timer(bar),@time必須寫在需裝飾的函數前面12 def bar():13     time.sleep(3)14     print("in the bar")15 16 bar()

無參數裝飾器

 

# Author = Johnstonimport timedef timer(func):    def deco(name):                       #傳遞參數name        start_time = time.time()        func(name)        end_time = time.time()        print("the function run time is %s" %(end_time-start_time))    return deco@timer  #bar = timer(bar)，@timer必須寫在需裝飾的函數前面def bar(name):    time.sleep(3)    print("%s is in the bar" %name)bar("Johnston")

 內參裝飾器 

 

 1 # Author = Johnston 2 import time 3 def outpara(type): 4     def timer(func): 5         def deco(name): 6             if type==1:          #根據外參數作為判斷執行條件 7                 start_time = time.time() 8                 func(name) 9                 end_time = time.time()10                 print("the function run time is %s" %(end_time-start_time))11             else:12                 print("wrong type")13         return deco14     return timer15 16 @outpara(type=1)  #傳遞條件參數，@outpara必須寫在需裝飾的函數前面
17 def bar(name): 
18 　　time.sleep(3) 
19 　　print("%s is in the bar" %name) 
20 
21 bar("Johnston")

外參裝飾器 

 

Python3 之裝飾器