import time

def timer(seconds): print(f"计时开始，时长：{seconds}秒") time.sleep(seconds)

ti

print("计时结束！")

if name == "main":

try: seconds =

int(input("请输入计时时长（秒）：")) timer(seconds)

    timer(seconds)
exc

    timer(seconds)


    timer(second

    timer(s

    t

except ValueError:

    prin

    p

print("输入无效，请输入一个整数作为计时时长。")

``