DNS resolution with Python

domains.py

import dns.message
import dns.name
import dns.rdatatype
import dns.query


def do_work(target, nameserver):
    qname = dns.name.from_text(target)
    responses = []
    for dtype in (dns.rdatatype.A, dns.rdatatype.NS):
        q = dns.message.make_query(qname, dns.rdatatype.A)
        r = dns.query.udp(q, nameserver, timeout=1.0)
        responses.append(r)
    assert any(len(r.answer) > 0 for r in responses)


def main():
    host = 'google.com'
    nameservers = [
        '8.8.8.8',
        '8.8.4.4',
        '208.67.222.222',
        '208.67.222.220',
    ]
    for nameserver in nameservers:
        do_work(host, nameserver)


if __name__ == '__main__':
    main()