python从子线程中获得返回值的方法

# coding:utf-8import time from threading import Thread def foo(number):  time.sleep(20)  return number class MyThread(Thread):   def __init__(self, number):    Thread.__init__(self)    self.number = number   def run(self):    self.result = foo(self.number)   def get_result(self):    return self.result  thd1 = MyThread(3)thd2 = MyThread(5)thd1.start()thd2.start()thd1.join()thd2.join() print thd1.get_result()print thd2.get_result()