Python开启一个线程定时器

import threading
import time
class aa(threading.Thread):
def __init__(self,no,interval):
"""Costructor"""
threading.Thread.__init__(self)
self.no = noself.interval =interval
self.isstop = False
def run(self):
while not self.isstop:
print 'thread %d' %self.no
time.sleep(self.interval)
def stop(self):
self.isstop = True
def factory():
t1=aa(1,2)
t1.start()
t1.sleep(20)
t1.stop()
if __name__ =="__main__"
factory()