python 串口通信多线程程序

import serial
import threading

class ComClass:
    def __init__(self,port,baud):
        self.port = port
        self.baud = baud
        self.comSerial = None
        self.run = False
        self.open()
        if self.run:
            self.thread1 = threading.Thread(target=self.receiveData)
            self.thread2 = threading.Thread(target=self.sendData)
            self.thread1.start()
            self.thread2.start()
            self.thread1.join()
            self.thread2.join()
            self.close()
        
    def open(self):
        try:
            self.comSerial = serial.Serial(self.port,self.baud)
            self.run = True
            print("打开串口成功")
        except:
            print("打开串口失败")
            self.close()
            
    def close(self):
       self.comSerial.close()
       print("关闭串口")

    def sendData(self):
        print("sendData")
        while self.run:
            send_data = input()
            if send_data:
                self.comSerial.write(send_data.encode('UTF-8'))
                print('发送数据：%s' % send_data)
            if send_data == "break":
                print("发送数据线程结束")
                self.run = False

    def receiveData(self):
        print("receiveData")
        while self.run:
            receive_data = self.comSerial.read(self.comSerial.inWaiting()).decode("gbk")
            if receive_data:
                print('接收数据：%s' % receive_data)

            if receive_data == "break":
                print("接收数据线程结束")
                self.run = False


a = ComClass('COM2',9600)
input("输入任意字符结束程序！")