Return DNS servers of a domain

returnDNS.py

import subprocess

def returnDNS(domain):
    ''' Return DNS servers of a domain '''
    
    proc = subprocess.Popen(["dig +short +time=2 -t ns " +domain],
                            stdout=subprocess.PIPE, stderr=subprocess.PIPE, shell=True)
    (out, err) = proc.communicate()
    
    return sorted(out.decode('utf-8').split())