装饰器

1.装饰器
1)本质就是函数，(装饰其他函数)，为其他函数添加附加功能
2)原则:
1.不能修改被装饰的函数源代码
2.不能修改被装饰的函数的调用方式

实现装饰器知识储备:
1.函数即”变量“
2.高阶函数
3.嵌套函数
高阶函数+嵌套函数=装饰器

案列一

import time
def trrm(fuc): #trrm(test1)
    def cod(*args,**kwargs):
        start_time=time.time()
        fuc(*args,**kwargs) #run test1()
        stop_time=time.time()
        print('the fuc run is %s' %(stop_time-start_time))
    return cod
@trrm
def test1():
    time.sleep(3)
    print('the is test1')
@trrm
def test2():
    time.sleep(3)
    print('the is test2')

test1()
test2()
>>>>>
the is test1
the fuc run is 3.0005998611450195
the is test2
the fuc run is 3.007200002670288

案列二

username,passwd = 'aron',123456
def verification(auth_type):
    def wrrit(fuck):
        def verifi(*args,**kwargs):
            if auth_type == "local":
                usernames = input("please enter user name:").strip()
                passworld = int(input("please enter passworld:"))
                if username == usernames and passwd == passworld:
                    fuck(*args,**kwargs)
                else:
                    exit()
            elif auth_type == "yuanc":
                exit("不会")
        return verifi
    return wrrit

def index():
    print("welcome to index page")

@verification(auth_type="local")
def home():
    print("welcome to home page")

@verification(auth_type="yuanc")
def bbs(arg1):
    print("welcome to %s page" %(arg1))

index()
home()
bbs(5)
>>>>>
welcome to index page
please enter user name:aron
please enter passworld:123456
不会
welcome to home page

Process finished with exit code 1