python 線程池 多線程

from Queue import Queue, Empty
from threading import Thread

THREAD_POOL_SIZE = 4




PLACES = (
    'Reykjavik', 'Vien', 'Zadar', 'Venice', 'Wroclaw', 'Bolognia',
    'Berlin', 'Slubice', 'New York', 'Dehli',
)

def fetch_place(place):
    # geocoded = api.geocode(place)[0]

    print(place)

def worker(work_queue):
    while not work_queue.empty():
        try:
            item = work_queue.get(block=False)
        except Empty:
            break
        else:
            fetch_place(item)
            work_queue.task_done()

def main():
    work_queue = Queue()
    for place in PLACES:
        work_queue.put(place)

    threads = [Thread(target=worker, args=(work_queue,))
               for _ in range(THREAD_POOL_SIZE)
               ]

    for thread in threads:
        thread.start()

    work_queue.join()

    while threads:
        threads.pop().join()

if __name__ == '__main__':
    main()