Python:检测父线程是否调用了exit()

import threading
import time

def child_thread():
    print("Child thread started")
    time.sleep(2)
    print("Child thread finished")

def parent_thread():
    print("Parent thread started")
    child = threading.Thread(target=child_thread)
    child.start()
    time.sleep(1)
    print("Parent thread finished")

if __name__ == "__main__":
    parent = threading.Thread(target=parent_thread)
    parent.start()
    parent.join()
    
    if not parent.is_alive():
        print("Parent thread called exit()")
    else:
        print("Parent thread did not call exit()")