multiprocessing.Process() 刚刚停止工作

Question

我在 Spyder 上自学 Python 中的多线程处理，并且正在研究一些相对简单的示例，但突然停止工作。回到以前有效的一些更简单的例子，现在它们似乎没有那么好用了。我想不出我能做些什么来让他们停止工作。以下是我的代码：

import time
import multiprocessing

start = time.perf_counter()

def do_something():
    print('Sleeping 1 second...')
    time.sleep(1)
    print('Done Sleeping...')


p1 = multiprocessing.Process(target = do_something)
p2 = multiprocessing.Process(target = do_something)

p1.start()
p2.start()

p1.join()
p2.join()


finish = time.perf_counter()


print(f'Finished in {round(finish - start, 2)} second(s)')

它似乎只是像中间部分一样运行：

p1 = multiprocessing.Process(target = do_something)
p2 = multiprocessing.Process(target = do_something)

p1.start()
p2.start()

p1.join()
p2.join()

没有吗？

编辑

唯一的输出是

Finished in 0.64 second(s)

没有错误信息。

Answer 1

您需要阅读error 并按照说明进行操作！

RuntimeError: 
        An attempt has been made to start a new process before the
        current process has finished its bootstrapping phase.

        This probably means that you are not using fork to start your
        child processes and you have forgotten to use the proper idiom
        in the main module:

            if __name__ == '__main__':
                freeze_support()
                ...

        The "freeze_support()" line can be omitted if the program
        is not going to be frozen to produce an executable.

请运行以下代码：

import multiprocessing


def worker(num):
    """Returns the string of interest"""
    return "worker %d" % num


def main():
    pool = multiprocessing.Pool(4)
    results = pool.map(worker, range(10))

    pool.close()
    pool.join()

    for result in results:
        # prints the result string in the main process
        print(result)


if __name__ == '__main__':
    # Better protect your main function when you use multiprocessing
    main()