python线程问题，python线程,代码：from thre

python线程问题，python线程,代码：from thre

代码：

from threading import Thread, Eventimport timedef countdown(n, start_env)：    print("countdown starting!")    start_env.set()    while n > 0:        print("T-minus", n)        n -= 1        time.sleep(2)start_env = Event()print('Launching Thread-countdown')t = Thread(target=countdown, args=(10, start_env))t.start()start_env.wait()print("countdown Running..............")t.join()

输出结果：

Launching Thread-countdowncountdown starting!T-minus 10countdown Running..............T-minus 9T-minus 8T-minus 7T-minus 6T-minus 5T-minus 4T-minus 3T-minus 2T-minus 1

我想问：为什么countdown Running 只在T-minus 10后输出一次？

编橙之家文章，