[FIXED] Multiprocessing on Python 3 Jupyter

Issue

I come here because I have an issue with my Jupiter's Python3 notebook. I need to create a function that uses the multiprocessing library. Before to implement it, I make some tests. I found a looooot of different examples but the issue is everytime the same : my code is executed but nothing happens in the notebook's interface :

The code i try to run on jupyter is this one :

import os

from multiprocessing import Process, current_process


def doubler(number):
    """
    A doubling function that can be used by a process
    """
    result = number * 2
    proc_name = current_process().name
    print('{0} doubled to {1} by: {2}'.format(
        number, result, proc_name))
    return result


if __name__ == '__main__':
    numbers = [5, 10, 15, 20, 25]
    procs = []
    proc = Process(target=doubler, args=(5,))

    for index, number in enumerate(numbers):
        proc = Process(target=doubler, args=(number,))
        proc2 = Process(target=doubler, args=(number,))
        procs.append(proc)
        procs.append(proc2)
        proc.start()
        proc2.start()

    proc = Process(target=doubler, name='Test', args=(2,))
    proc.start()
    procs.append(proc)

    for proc in procs:
        proc.join()

It's OK when I just run my code without Jupyter but with the command "python my_progrem.py" and I can see the logs :

Is there, for my example, and in Jupyter, a way to catch the results of my two tasks (proc1 and proc2 which both call thefunction "doubler") in a variable/object that I could use after ? If "yes", how can I do it?

Solution

Another way of running multiprocessing jobs in a Jupyter notebook is to use one of the approaches supported by the nbmultitask package.

Answered By - psychemedia