mtsleepD.py

#!/usr/bin/env python3
"""
This script demonstrates basic use of threading.Thread class with its
'target' parameter as an object.
"""

import threading
from time import sleep, ctime

loops = [4, 2]

class ThreadFunc():
    """Callable class instance to be used as a 'target' to the Thread object."""
    def __init__(self, func, args, name=''):
        self.name = name
        self.func = func
        self.args = args

    def __call__(self):
        self.func(*self.args)


def loop(nloop, nsec):
    print("starting loop", nloop, "at:", ctime())
    sleep(nsec)
    print("loop ", nloop, "done at:", ctime())

def main():
    print("starting at:", ctime())
    threads = []
    nloops = range(len(loops))

    for i in nloops:
        t = threading.Thread(
        target=ThreadFunc(loop, (i, loops[i]), loop.__name__)
        )
        threads.append(t)

    for i in nloops:  # Starts threads
        threads[i].start()

    # Waits for all threads to finish.
    for i in nloops:
        threads[i].join()

    print("all DONE at:", ctime())

if __name__ == "__main__":
    main()