python multithreading semaphore

sema.py

#!/usr/bin/env python

import threading 
import urllib2
import time, random

class GrabUrl(threading.Thread):
	def __init__(self, arg0):
		threading.Thread.__init__(self)
		self.host = arg0
	def run(self):
		k = random.randint(10, 20)
		print "Processing " + self.host + " waiting for : " + str(k)
		time.sleep(k)
		print "exiting " + self.host
		pool.release()


class Handler(threading.Thread):
	def __init__(self):
		threading.Thread.__init__(self)
	def run(self):
		for i in hosts:
			pool.acquire()
			graburl = GrabUrl(i)
			graburl.setDaemon = True
			graburl.start()


maxconn = 2
pool = threading.BoundedSemaphore(value=maxconn)
hosts = ['http://yahoo.com', 'http://google.com', 'http://amazon.com', 
		'http://ibm.com', 'http://apple.com']
print str(len(hosts))
handler = Handler()
handler.start(handler.join()
print "exiting main"