第十讲--函数（装饰器）

##1.写一个装饰器，对已经存在的函数，计算函数执行的时间；
import time

def fn1():
    def fn():
        print('fn执行了')
        i = 1
        while True:
            yield i
            i+=1
    result = fn()
    i = 0
    while i <20:
        print(next(result))
        time.sleep(1)
        i +=1

def cal_time(fun):
    start_time = int(time.time())
    fun()
    end_time = int(time.time())
    print(start_time,end_time)
    return end_time - start_time

if __name__ == '__main__':
    time = cal_time(fn1)
    print('生成器的运行时间是{}秒'.format(time))