python socket recvfrom_Python：socket.recvfrom()不返回任何地址

我正在尝试编写示例here的Python版本,但是由于某种原因,我在客户端和服务器中对socket.recvfrom()的每次调用都将其地址返回值为None.我唯一能想到的可能是套接字是STREAM套接字,但是当我尝试将类型更改为socket.SOCK_DGRAM时,调用socket.listen()时出错.我该如何解决这个问题？

def server(port):

sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

sock.bind((‘127.0.0.1’, port))

sock.listen(5)

clientsocket, address = sock.accept()

kkp = KnockKnockProtocol(); #Class which implements knock knock

outputLine = kkp.processInput();

clientsocket.sendto(outputLine, address)

inputLine, address = clientsocket.recvfrom(MAX_BYTES)

while inputLine:

print inputLine, address

outputLine = kkp.processInput(inputLine);

clientsocket.sendto(outputLine, address)

if outputLine == “Bye.”:

break

inputLine, address = clientsocket.recvfrom(MAX_BYTES)

def client(port):

sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

sock.connect((“127.0.0.1”, port))

fromServer, address = sock.recvfrom(MAX_BYTES)

while fromServer:

print “Server: ” + fromServer

if fromServer == “Bye.”:

break

fromUser = raw_input()

if fromUser:

print “Client: ” + fromUser

sock.sendto(fromUser, (“127.0.0.1”, port))

fromServer, address = sock.recvfrom(MAX_BYTES)

if __name__ == ‘__main__’:

choices = {‘client’: client, ‘server’: server}

parser = argparse.ArgumentParser(description=’Send and receive UDP locally’)

parser.add_argument(‘role’, choices=choices, help=’which role to play’)

parser.add_argument(‘-p’, metavar=’PORT’, type=int, default=1060, help=’UDP port (default 1060)’)

args = parser.parse_args()

function = choices[args.role]

function(args.p)

解决方法:

使用数据报套接字或流套接字.您正在尝试分割差异.您要使用哪个？如果要基于连接的字节流协议,请使用流套接字.如果您需要无连接的数据报协议,请使用数据报套接字.

如果要使用流套接字,请不要使用recvfrom.它基于连接,唯一可以接收的是来自该特定连接的字节.

如果要使用数据报套接字,请不要使用监听或接受.由于它是无连接的,因此您既不能监听也不能接受连接.

标签：sockets,python

来源： https://codeday.me/bug/20191119/2037321.html