def metric(fn):    def wrapper(*args,**kwargs):        #获取当前时间        start_time = time.time()        #调用原始函数        result = fn(*args,**kwargs)        #获取当前时间        end_time = time.time()        #计算执行时间（转换为毫秒）        duration = (end_time - start_time)*1000        print('%s executed in %.2f ms' % (fn.__name__,duration))        return result    return wrapper