20190527 装饰器

import time

def f():
    print('hello')
    time.sleep(2)
    print('world')
    time.sleep(1)

def calculate_time():
    start_time=time.time()
    f()
    end_time=time.time()
    execuate_time=((end_time-start_time)*1000)
    return execuate_time
print(calculate_time())


#在不改变原函数代码的基础上给涵数f增加新功能,使用装饰器实现
def deco(f):
    def wrapper():
        start_time=time.time()
        f()
        end_time=time.time()
        execuate_time=(end_time-start_time)*1000
        print(execuate_time)
    return wrapper
@deco
def f():
    print('hello')
    time.sleep(1)
    print('world')

if __name__=='__main__':
    f()