python中的多线程----以2个线程卖票为例

#!/usr/bin/python# -*- coding: UTF-8 -*-#目标：线程1和线程2轮流切换卖100张票

import timeimport threadingif __name__ == '__main__':   con= threading.Condition()   def job():      global num      con.acquire()      con.notify()      if num>=1:         try:            print "线程%s正在售卖%d" % (threading.current_thread().name, num)            num -= 1         finally:            con.wait()                        #两个线程都会持有锁，且不会释放了   def task():      while True:         job()   t3=threading.Thread(target=task,name="线程1")   t4=threading.Thread(target=task,name="线程2")   t3.start()   t4.start()