python 装饰器

import time
def func():
    time.sleep(0.1)
    print(‘hello‘)

def timer(f):
    def inner():
        start=time.time()
        f()  #被装饰的函数
        end=time.time()
        print(end-start)
    return inner

func=timer(func)# time(func)得到的是inner
func()

def timer(f):
    def inner():
        start=time.time()
        f()
        end=time.time()
        print(end-start)
    return inner

@timer  #这里相当于func=time(func)
def func():
    time.sleep(0.1)
    print(‘hello‘)


func()