python继承threading.Thread如何实现有返回值的子类

import threading
class MyThread(threading.Thread):
  def __init__(self,func,args=()):
    super(MyThread,self).__init__()
    self.func = func
    self.args = args
  def run(self):
    self.res = self.func(*self.args)
  def getResult(self):
    try:
      return self.res 
    except Exception:
      return None

import threading
from time import sleep
exitFlag = True
def pp1(*args):
  i = 1
  while(exitFlag):
    print('\r'+' '*20,end='')
    print('\r线程1运行中'+'.'*(i%7),end='')
    sleep(0.5)
    i = (i>=6 and 1 or i+1)  #if i>=6则i=1，否则i=i+1
  print('线程1结束')

def pp2(x,y):
  sleep(3)
  print('\n线程2结束')
  return x + y

class MyThread(threading.Thread):  #MyThread类继承threading.Thread类
  def __init__(self,func,args1=None,args2=None):
    threading.Thread.__init__(self)
    self.func = func
    self.args1 = args1
    self.args2 = args2
  def run(self):     #t.start()语句调用run方法
    self.result = self.func(self.args1,self.args2)  
  def getResult(self):  #getResult方法可获得func函数return的结果
    threading.Thread.join(self)
    return self.result

t1 = MyThread(pp1)   #初始化t1
t2 = MyThread(pp2,2,3) #初始化t1
t1.start()  #启动线程t1
t2.start()  #启动线程t2
t2.join()   #判断线程t2运行结束
exitFlag = False  #线程2运行结束后，线程1才能结束
t1.join()  #判断线程t1运行结束，线程t1结束后，主线程才能往下运行
print('线程2返回结果: ',t2.getResult())
print('主线程结束')