我想用Python制作一個(gè)多進(jìn)程UDP服務(wù)器，從類監(jiān)聽(tīng)每個(gè)進(jìn)程的一個(gè)端口：processListener.py：import multiprocessingimport socketclass processListener(multiprocessing.Process):def __init__(self):    multiprocessing.Process.__init__(self)    self.data = Nonedef run(self):    self.startServer()    returndef startServer(self):    udpSocket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)    address = ('', self.port)    udpSocket.bind(address)    while 1:        data, client = udpSocket.recvfrom(1024)        print self.data, '>>>', data.strip()        self.data = data.strip()        udpSocket.sendto('ACK', client)    return而我的主文件是server.py：from processListener import *# Variable Definitionport = 4000# Sever Initializationif __name__ == '__main__':process = processListener()process.port = portprocess.start()while True:    command = raw_input()    if command == 'showdata':            print 'Last Data is:', process.data當(dāng)服務(wù)器運(yùn)行時(shí)，我從UDP發(fā)送數(shù)據(jù)到localhost：4000shell$ None >>> Test Data但是問(wèn)題開(kāi)始于我使用命令 showdatashell$None >>> Test DatashowdataLast Data is: None