python - 运行时错误: threads can only be started once for a beginner

Question

这是我的第一个程序。我试图将此加载动画放入 while 循环中，但它在第二个“f.start()”之后给出此错误。由于我对线程不太了解，所以我在 Google 上找到的“帮助”根本没有帮助，其中涉及类创建和所有内容的长代码。有人可以帮助我了解我可以在这里做什么吗？

我从这里复制了动画代码:Python how to make simple animated loading while process is running

<小时/>

import itertools
import threading
import time
import sys


#here is the animation
def animate():
    for c in itertools.cycle(['|', '/', '-', '\\']):
        if done:
            break
        sys.stdout.write('\rloading ' + c)
        sys.stdout.flush()
        time.sleep(0.25)
    sys.stdout.write('\rDone!     ')

t = threading.Thread(target=animate)

while True:
    done = False
    user_input = input('Press "E" to exit.\n Press"S" to stay.')
    if user_input is "E":
        break
    elif user_input is "S":
        # Long process here
        t.start()
        time.sleep(5)
        done = True
        time.sleep(1)
        print("\nThis will crash in 3 seconds!")
        time.sleep(3)
        break


# Another long process here
t.start()
time.sleep(5)
done = True

Answer 1

正如错误所示，一个线程只能启动一次。因此，请创建一个新线程。另请注意，我使用 join 来等待旧线程停止。

import itertools
import threading
import time
import sys


#here is the animation
def animate():
    for c in itertools.cycle(['|', '/', '-', '\\']):
        if done:
            break
        sys.stdout.write('\rloading ' + c)
        sys.stdout.flush()
        time.sleep(0.25)
    sys.stdout.write('\rDone!     ')

t = threading.Thread(target=animate)

while True:
    done = False
    user_input = input('Press "E" to exit.\n Press"S" to stay.')
    if user_input is "E":
        break
    elif user_input is "S":
        # Long process here
        t.start()
        time.sleep(5)
        done = True
        t.join()
        print("\nThis will crash in 3 seconds!")
        time.sleep(3)
        break


# Another long process here
done = False
t = threading.Thread(target=animate)
t.start()
time.sleep(5)
done = True