Python multiprocessing hello world. Split a list and process sublists in different jobs

multiprocessing_with_joining_back_results.py

import multiprocessing
import os
# split a list into evenly sized chunks
def chunks(l, n):
    return [l[i:i+n] for i in range(0, len(l), n)]


def do_job(job_id, data_slice, queue):
    for item in data_slice:
        print ("job", job_id, item)
        queue.put(item + ' done by job ' + str(job_id))
        


def dispatch_jobs(data, job_number):
    total = len(data)
    chunk_size = total // job_number
    slice = chunks(data, chunk_size)
    jobs = []
    queue = multiprocessing.Queue()
    for i, s in enumerate(slice):
        j = multiprocessing.Process(target=do_job, args=(i, s, queue))
        jobs.append(j)
    for j in jobs:
        j.start()
    for j in jobs:
        j.join()
    while not queue.empty():
        print(queue.get())
        
    


if __name__ == "__main__":
    data = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p']
    dispatch_jobs(data, os.cpu_count())