# queue_join.py

from queue import Queue
from threading import Thread
from datetime import datetime

num_worker_threads = 4

def worker():
    while True:
        item = q.get()
        print(item, datetime.now())
        q.task_done()

q = Queue()
for i in range(num_worker_threads):
     t = Thread(target=worker)
     t.daemon = True
     t.start()

for item in range(10):
    q.put(item)

q.join()       # block until all tasks are done