import socket

dictlist ={};

def ReadHost():

    hosts = [];

    obn = open('d:/sss.txt', 'rb');

    for line in obn:

        #sometime you should filter \r\n

        line = line.strip('\n')

        hosts.append(line)

    obn.close();

    return hosts;

def SysDNS():

    hosts = ReadHost();

    for host in hosts:

        #print(host)

        try:

            myaddrs = socket.getaddrinfo(host,None)

            for eachaddr in myaddrs:

    	        addrs = eachaddr[4][0]

                #print((addrs))

                if(dictlist.has_key(addrs)):

                    break;

                else:

                    dictlist[addrs] = host;

                    #print(host)

                    break;

        except socket.herror,e:

            continue;

        except socket.gaierror,e1:

            continue;

def showDict():

    fw = open("d:/out.txt","wb");

    for (k,v) in dictlist.items():

        #print(k,v)

        fw.writelines(v);

    fw.close();

if __name__ == "__main__":

    SysDNS();

    showDict();