python3 - 这里的job.get()是什么含义？

Question

代码来源
https://medium.com/geekculture/python-multiprocessing-with-ou...

import multiprocessing as mp

def worker_function(item):
    """
    do some work, write results to output
    """
    res = f'item: {item} - result: {item ** 2}'
    print(res)
    with open('output_no_queue.txt', 'a') as f:
        f.write(str(res) + '\n')


if __name__ == '__main__':
    pool = mp.Pool(16)
    jobs = []
    for item in range(10000):
        job = pool.apply_async(worker_function, (item, ))
        jobs.append(job)

    for job in jobs:
        job.get()

    pool.close()
    pool.join()

这里的job.get()是表达什么呢？jobs是个list,每个job也不是queue,list的元素没有get方法，如何理解呢？

Answer 1

job 是 apply_async 的返回值，是 AsyncResult 类的对象。这个类的对象的 get:

Return the result when it arrives. If timeout is not None and the result does not arrive within timeout seconds then multiprocessing.TimeoutError is raised. If the remote call raised an exception then that exception will be reraised by get().

Answer 2

job = pool.apply_async(worker_function, (item, ))

job 的类型是个 pool.apply_async 的返回值类型，也即 AsyncResult 对象。

所以你就看它的 get 方法是干啥的呗。

https://docs.python.org/zh-cn/3/library/multiprocessing.html#...