Python单例模式__new__实现

__new__实现的串口单例，查了很多单例格式，都只有框架怎么用的案例没有，学习了一下做记录，如果有问题欢迎来拍砖。

import sys
import serial
import serial.tools.list_ports
import threading
import time

class SerialComm(object):
    _instance_lock = threading.Lock()
    def __new__(cls,commport,
                 baudrate,
                 bytesize=8,
                 parity=serial.PARITY_NONE,
                 stopbit=1,
                 timeout=5):
        if not hasattr(SerialComm,"_instance"):
            with SerialComm._instance_lock:
                if not hasattr(SerialComm,"_instance"):
                    SerialComm._instance = CommFunc(commport, baudrate, bytesize, parity, stopbit, timeout)
        return SerialComm._instance

class CommFunc(object):
    def __init__(self,commport,baudrate,bytesize=8,
                 parity=serial.PARITY_NONE,stopbit=1,timeout=5):
        self.bAsynRecv = False
        self.bStartRecv = False
        self.recvThd = None
        self.comm = \
            serial.Serial(commport, baudrate, bytesize, parity, stopbit, timeout)

    @staticmethod
    def getPortList():
        nameList = []
        infoList = list(serial.tools.list_ports.comports())
        if len(infoList) > 0:
           for i in range(len(infoList)):
               tmpList = list(infoList[i])
               nameList.append(tmpList[0])
        return nameList

    def setAsynRecv(self, callBackFunc):
        self.bAsynRecv = True
        self.bStartRecv = True
        self.callFunc = callBackFunc
        self.recvThd = threading.Thread(target=self.recvThread,daemon=True)
        self.recvThd.start()

    def openComm(self):
        if self.comm.isOpen():
            return True
        else:
            self.comm.open()
            if self.comm.isOpen():
                return True
            else:
                return False

    def modifyComm(self, baudrate=115200,bytesize=8,parity=serial.PARITY_NONE,
                   stopbit=1, timeout=5, bAsnyRecv=True):
        commName = self.comm.port()
        bAsynRecv = self.bAsynRecv
        self.closeComm()
        self.comm = serial.Serial(commName,baudrate,bytesize,
                                  parity,stopbit,timeout)
        self.openComm()
        if bAsnyRecv:
            self.setAsynRecv()

    def closeComm(self):
        if self.bStartRecv:
            self.bStartRecv = False
            time.sleep(5)
        if self.comm.isOpen():
            self.comm.close()
        return

    def sendData(self, data):
        len = self.comm.write(data)
        return len

    def recvData(self):
        return self.comm.readall()

    def recvThread(self):
        while self.bStartRecv:
            content = self.recvData()
            if self.callFunc is not None:
                self.callFunc(content)
            print(content)

if __name__ == "__main__":
    portList = CommFunc.getPortList()
    print(portList[0],len(portList))
    comm = SerialComm("COM3",baudrate=115200)
    comm.openComm()
    comm.setAsynRecv(None)
    time.sleep(6)
    comm.closeComm()