FunctionAsProcess.py

'''
Start 3 processes using a function 'f()' as the entry point.
Start 3 instances and wait for completion.
Print activity showing overlapping execution of all processes.
'''

import multiprocessing
import time


def log(proc, msg):
 print(' ' * 2 * proc, "Parent" if 0 == proc else proc, msg)


def f(args):
 log(args, "start")
 for i in range(5):
 log(args, "tick{0}".format(i))
 time.sleep(0.01)
 log(args, "done")


if __name__ == '__main__':
 log(0, "start")
 p1 = multiprocessing.Process(target=f, args=[1])
 p2 = multiprocessing.Process(target=f, args=[2])
 p3 = multiprocessing.Process(target=f, args=[3])
 p1.start()
 p2.start()
 p3.start()
 log(0, "wait")
 p1.join()
 p2.join()
 p3.join()
 log(0, "done")