#!/usr/bin/env python
# -*- coding: utf-8 -*-
from threading import Thread
from Queue import Queue
class MyThreadPool(object):
    def __init__(self, num_threads=20):
        self.tasks = Queue(num_threads)
        for _ in xrange(num_threads):
            # Init the pool with the number of num_threads
            MyThread(self.tasks)
    def add_task(self, func, *args, **kwargs):
        self.tasks.put((func, args, kwargs))
    def wait_completion(self):
        # Blocks until all items in the queue have been gotten and processed.
        self.tasks.join()
class MyThread(Thread):
    def __init__(self, tasks):
        Thread.__init__(self)
        self.tasks = tasks
        # This must be set before start() is called. The entire Python program
        # exits when no alive non-daemon threads are left.
        self.daemon = True
        self.start()
    def run(self):
        while True:
            # Block until an item is available.
            func, args, kwargs = self.tasks.get()
            try:
                func(*args, **kwargs)
            except Exception as e:
                print e
            # Tells the queue that the processing on the task is complete.
            self.tasks.task_done()
if __name__ == '__main__':
    ''' test task '''
    from time import sleep
    def nap(sec):
        sleep(sec)
        print 'Had a %ds nap...' % sec
    tp = MyThreadPool(5)
    nap_time = [i for i in xrange(1, 11)]
    for i, t in enumerate(nap_time, 1):
        print 'Worker No.%d needs a %ds nap.' % (i, t)
        tp.add_task(nap, t)
    tp.wait_completion()