Example

import os

def child():

print('A new child ', os.getpid())

os._exit(0)

def parent():

while True:

newpid = os.fork()

if newpid == 0:

child()

else:

pids = (os.getpid(), newpid)

print("parent: %d, child: %d" % pids)

if input( ) == 'q':

break

parent()