python装饰器

#通过引用全局变量来控制账号登陆
flag = False
def login(func):
    def inner(*args,**kwargs):
        global flag
        if flag:
            ret = func(*args, **kwargs)
            return ret
        else:
            username = input('user:')
            password = input('pswd:')
            if username == 'ryan' and password == '123456':
                flag = True
                ret = func(*args, **kwargs)
                return ret
    return inner


@login
def say_hi():
    print('hello world')

@login
def say_bye():
    print('goodbye my friends')

say_hi()
say_bye()

 计时器：

from time import time
from time import sleep
def timmer(func):
    def inner(*args,**kwargs):
        start = time()
        ret = func(*args,**kwargs)
        end = time()
        print(end - start)
        return ret
    return inner


@timmer
def func_1(words):
    sleep(1)
    print(words)


@timmer
def func_2(words):
    sleep(2)
    print(words)


func_1('你好呀')
func_2('你是大坏蛋')