PubNub和Python的multiprocessing.Process不兼容吗？

Question

我正在尝试使用Python的multiprocessing.Process包（Raspbian 9上的Python 3.5-Stretch）在一个进程内从PubNub接收消息。

以下代码可以完美地作为独立程序运行，也可以在使用Python线程包的线程内完美运行。但是，它不适用于multiprocessing.Process。

我是否缺少某些东西，还是PubNub的SubscribeListener与Python的多处理程序包不兼容？

XDocument doc = XDocument.Load("dati.txt");

doc.Descendants().Elements("name")           //all "name" elements
    .Where(d => d.Value == selectednode)     //where node value is user input
    .Where(d => d.Parent.Name == "setting")  //and also its parent element name is "setting"
    .Select(d => d.Parent)                   //Select name's parent
    .Remove();                               //Remove it

//optionally save the xml back to the file or whatever you intend to do with it.

Answer 1

PubNub和Python多重处理

我无法让SDK处理多处理工作程序中的同步请求。但是，以下技巧非常有效：

一起使用多处理和PubNub

简单的example.py文件包含以下代码：

import multiprocessing
import requests

SUB_KEY  = 'demo'
CHANNELS = ['my_channel']

def main():
    mp = multiprocessing.Process(target=subscriber)
    mp.start()
    mp.join()

def subscriber():
    timetoken = '0' ## pointer to last message received
    while True:
        url = "/".join([
            'https://ps.pubnub.com/subscribe'
        ,   SUB_KEY
        ,   ",".join(CHANNELS)
        ,   '0'
        ,   timetoken
        ])

        print(url)

        response  = requests.get(url)
        data      = response.json()
        messages  = data[0]
        timetoken = data[1]

        print(data)

if __name__ == '__main__': main()

多处理子进程的输出

> python example.py 
https://ps.pubnub.com/subscribe/demo/my_channel/0/0
[[], u'15336927707090912']
https://ps.pubnub.com/subscribe/demo/my_channel/0/15336927707090912
[[{u'text': u'hey'}], u'15336927943808959']
https://ps.pubnub.com/subscribe/demo/my_channel/0/15336927943808959
[[{u'text': u'hey'}], u'15336927945476647']
https://ps.pubnub.com/subscribe/demo/my_channel/0/15336927945476647
[[{u'text': u'hey'}], u'15336927946996529']
https://ps.pubnub.com/subscribe/demo/my_channel/0/15336927946996529
[[{u'text': u'hey'}], u'15336927948441519']
https://ps.pubnub.com/subscribe/demo/my_channel/0/15336927948441519
[[{u'text': u'hey'}], u'15336927950007602']
https://ps.pubnub.com/subscribe/demo/my_channel/0/15336927950007602