Python multiprocessing TypeError: join() takes exactly 1 argument (2 given)

Question

我对多处理做了很多研究！基本上我是从 API 下载数据并插入数据库。

我创建了一个池并使用 pool.imap 访问下载功能，用结果创建一个元组并一次性插入数据库中。

我反复访问这个函数，有时我的进程挂了！我已尝试关注 https://docs.python.org/2/library/multiprocessing.html#multiprocessing.pool.multiprocessing.Pool.map 并访问超时连接。

但是pool.join（超时）returns"TypeError: join() takes exactly 1 argument (2 given)"。我想一个参数是默认的 "self"?

一小段代码：

timeout = 10
pool = Pool(10)
in_tuple = [x for x in pool.imap(multi_details,items) if x is not None]
pool.close()
pool.join(timeout) # from the documentation I should be able to put the timeout in join

writing_to_database(in_tuple)

# function that generate the content for DB
def multi_details(item):
        tuple = get_details(item)
        return tuple

我看到了创建进程和生成 terminate() 或 join(timeout) 的不同方法，但都没有使用 imap/map - 在我的案例中，这更简单！

Answer 1

与 Process class 不同，Pool class 在其 join 方法中不接受 timeout 参数： https://docs.python.org/2/library/multiprocessing.html#multiprocessing.pool.multiprocessing.Pool.join

Answer 2

这就是解决方案！

我没能使用 "next(timeout)" 因为它只解析了几个项目而不是在运行整个列表之前停止！

我开始使用apply_async。唯一就是我有种奇怪的感觉，比imap.

慢

功能代码为：

timeout = 1
pool = Pool(10)
for x in items:
    try:
        res = pool.apply_async(multi_details,(x,)).get(timeout)
    except Exception as e:
        pass # you can put anything you want but my scope was to skip the things that took too much!
    else:
        if res is not None: # now this could be a better pythonic way to write this. Any help will be highly appreciated!
            in_tuple.append(res)
pool.close()
pool.join()

谢谢，希望有用！

Python multiprocessing TypeError: join() takes exactly 1 argument (2 given)

Python multiprocessing TypeError: join() takes exactly 1 argument (2 given)

python

multithreading

terminate

multiprocessing