What am I missing here in Multi-Processing?

Question

import multiprocessing
import time

def sq(a):
    for n in a:
        time.sleep(0.2)
        print('square '+str(n*n))

def cub(a):
    for n in a:
        time.sleep(0.2)
        print('cube '+str(n*n*n))

if __name__ == "__main__":
    arr=[2,3,4,5]
    p1=multiprocessing.Process(target=sq,args=(arr,))
    p2=multiprocessing.Process(target=cub,args=(arr,))

    p1.start()
    p2.start()

    p1.join()
    p2.join()

    print('done')

Here I'm getting output only done but not the square and cube.

This is the code what I'm trying for multi-processing. I got the output in case of multi-threading as most of syntax is same but not in case of multi-processing.

Answer 1

Unfortunately the multiprocessing library in Python will not work in an IDE. I just double checked with 2 IDEs in 2 different environments but none of them accesses the methods. When I ran it from the command line it worked fine. There is an explanation in this post here Python multiprocessing

Edit:

From the video you shared in your comment, it appears that Pycharm is an exception. I tested in mine and it worked. The point is there is nothing wrong with the code. If it is not working in your IDE, it means it is not supported. So I guess you can either use Pycharm like in the tutorial or use command line.