a simple multi-threading in Python

multi-threading_simple.py

import threading
import urllib
import time

class Mythread(threading.Thread):
	'''Download pictures.'''
	def __init__(self, url):
		threading.Thread.__init__(self)
		self.url = url
		print 'init thread.'

	def run(self):
		print 'thread running'
		print 'begin downloading from %s' % self.url
		urllib.urlretrieve(self.url, r'./' + self.url[7 : 12] + '.jpg')

starttime = time.time()

def main():
	# some pictures' urls
	urllist = ['http://soso7.gtimg.cn/sosopic/0/6704014884959496047/640', 
		   'http://soso1.gtimg.cn/sosopic/0/5484709051946749088/640']
	for url in urllist:
		mythread = Mythread(url)
		mythread.start()
	print 'main thread continues.'
	# wait for mythread
	mythread.join()
	print 'main thread waiting for mythread.'
	print 'Time : %s' % (time.time() - starttime)

if __name__ == '__main__':
	main()