错误全局名称'SOL_SOCKET未定义

Question

我正在尝试创建一个基本的即时消息程序，它使用p2p（点对点）连接，这样就不需要服务器。我很确定没有什么问题，但是每次运行我创建的客户端程序时，我都会得到以下错误： s、 setsockopt（SOL_SOCKET，SO_REUSEADDR，1） 名称错误：未定义全局名称“SOL_SOCKET” 程序如下：

import socket

def Receiver():

    # Create socket that supports IPv4, TCP Protocol
    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    print "Socket created."
    # Requests for IP of host (DNS)
    dns = "localhost"
    HOST = ''
    PORT = 25395
    try:

        s.setsockopt(SOL_SOCKET, SO_REUSEADDR, 1)
    except socket.error as serror:
        print "socket error"
    s.bind((HOST, PORT)) # Listens on all interfaces...
    print 'Listening on port 25565'
    s.listen(True) # Listen on the newly created socket... 
    conn, addr = s.accept()
    print 'Connected in port 25565'
    data = conn.recv(1024)
    print data
    s.close()
def Sender():

    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    dns = "localhost"
    HOST = socket.gethostbyname(dns)
    port = 25565    
    # Connect to server
    s.connect((host,port))

    print "Socket connected to " + dns + " on IP " + host

    # Assign message to be sent to server to a variable
    message = raw_input("Message to be sent to server: ")

    #Send the actual message to server
    s.sendall(message)
    print "Message sent successfully"
    s.close()


input = raw_input('S is send, R is receive: ')
if input == 's':
    Sender()
if input == 'r':
    Receiver()

我试过删除s.setsockopt（SOL_SOCKET，SO_REUSEADDR，1），但它告诉我，如果没有两个套接字使用同一端口，则不能在同一端口上使用两个套接字。