mutliprocessing using pool with apply_async with callback

mutliprocessing_apply_async_with_callback.py

from multiprocessing import Pool
import os
import time

list_of_movie_names = ["john_wick_1", "john_wick_1", "john_wick_3"]


def hello_world(name):
    print("IT WASN'T JUST A PUPPY")
    time.sleep(1)
    print('YOU WANTED ME BACK...')
    return f"Hello: {name}"


results = []


def response(result):
    results.append(result)


def demo_multi_processing():
    tic = time.time()
    pool = Pool(processes=os.cpu_count())

    for name in list_of_movie_names:
        pool.apply_async(hello_world, args=(name,), callback=response)

    pool.close()
    pool.join()

    print(results)
    toc = time.time()
    print(f'Completed in {toc - tic} seconds')


if __name__ == '__main__':
    demo_multi_processing()