t.py

import time

import concurrent.futures
import psutil


def test(x):
    print('entering', x)
    time.sleep(1)
    print('exiting', x)

 
with concurrent.futures.ProcessPoolExecutor(max_workers=1) as executor:
    out = [executor.map(test, range(100))]
    for _ in range(20):
        time.sleep(1)
        for child in psutil.Process().children():
            print(' - - - - - -', child)
    concurrent.futures.wait(out)