Is there an way to start a python script and keep it running as process until user says stop explicitly

Question

I am looking something like this.
If i have a method in a class, now that i accept 2 command line arguments (start, stop), so when i run python script.py start, it will start automatically, now after sometime if user enters script.py stop it should end gracefully, can it be done.

This is what i have tried to do

from multiprocessing import Process, Queue
from time import sleep
import sys

def start(name):
    print('hello', name)
    print "Sleeping for 60 sec"
    # sleep (60)



if __name__ == '__main__':


p = Process(target=start, args=('bob',))
p.start()

Thanks