当第一个在 python3 中完成时，如何终止并行进程？

Question

问题：如何在进程号 1 完成后停止进程号 2？

加长版：我编写了一个多进程 2 个函数的脚本，但我真的不知道如何在第一个进程完成后停止第二个进程。

我的代码：

def printHelloWorld(): # So this takes 5.0053 seconds to completly run
    print("Hello World.")
    time.sleep(5)
    print("Hello World. (after 5 seconds)")


def printText(): # And this takes 10.0102 seconds to completly run
    print("Some text.")
    time.sleep(10)
    print("Some text. (after 10 seconds)")


if __name__ == "__main__": # I multiprocessed these 2 functions to reduce time. 
    # But what I actually want is to terminate process 2 when process 1 has finished.
    p1 = Process(target = printHelloWorld) 
    p2 = Process(target = printText)
    p1.start()
    p2.start()          
    p1.join()
    p2.join()

我尝试了一个 while 循环来检查 p1.is_alive == False 何时应该终止进程 2，但它不起作用。我也搜索了答案，但没有找到符合我要求的答案。

感谢您阅读/回答！

让我澄清一些事情：如果我无法正确解释，我很抱歉，但我想问的是，我如何检查哪个进程首先完成并终止第二个进程，因为它不再需要？

示例：如果我们不知道函数 1 和 2 的执行时间怎么办（这两个函数都在一个并行进程中）。因此，一旦第一个进程停止，我希望另一个进程停止。我怎样才能做到这一点？我希望现在可以清楚地描述这一点。再次抱歉造成混乱！

Answer 1

我建议您使用 Pebble 库。它包装了 Python 的标准库线程和多处理对象。但它很有可能取消正在运行的通话。

import time
from concurrent.futures import wait, FIRST_COMPLETED
from pebble import ProcessPool

def printHelloWorld():  # So this takes 5.0053 seconds to completly run
    print("Hello World.")
    time.sleep(5)
    print("Hello World. (after 5 seconds)")


def printText():  # And this takes 10.0102 seconds to completly run
    print("Some text.")
    time.sleep(10)
    print("Some text. (after 10 seconds)")


if __name__ == "__main__":  # I multiprocessed these 2 functions to reduce time.
    with ProcessPool(max_workers=2) as pool:
        f1 = pool.schedule(printHelloWorld)
        f2 = pool.schedule(printText)
        done, not_done = wait((f1, f2), return_when=FIRST_COMPLETED)
        for f in not_done:
            f.cancel()

Answer 2

你试过Process.terminate吗？

import time
from multiprocessing import Process


def printHelloWorld(): # So this takes 5.0053 seconds to completly run
    print("Hello World.")
    time.sleep(5)
    print("Hello World. (after 5 seconds)")


def printText(): # And this takes 10.0102 seconds to completly run
    print("Some text.")
    time.sleep(10)
    print("Some text. (after 10 seconds)")


if __name__ == "__main__": # I multiprocessed these 2 functions to reduce time.
    # But what I actually want is to terminate process 2 when process 1 has finished.
    p1 = Process(target = printHelloWorld)
    p2 = Process(target = printText)
    p1.start()
    p2.start()
    p1.join()
    p2.terminate()  # terminate process 2
    p2.join()