mp_spawn.py

import multiprocessing as mp
import subprocess
import sys
import time

import os

print("hello!", sys.argv)


def foo(e):
    print("hi")
    e.wait()
    print("bye")


if __name__ == '__main__':
    print("main")
    mp.set_start_method('spawn')
    e = mp.Event()
    p = mp.Process(target=foo, args=(e,))
    p.start()
    time.sleep(0.5)
    cmd = "pstree -a {}".format(os.getpid())
    print(subprocess.check_output(cmd, shell=True, universal_newlines=True))
    e.set()
    p.join()
    print("done")