Python domain checker

domain.py

#!/usr/bin/env python
import sys 
import socket
import itertools

def filter_tlds(x): return x.startswith(".")

tlds = set(filter(filter_tlds, sys.argv[1:]))
non_tlds = set(sys.argv[1:]).difference(tlds)

for permutation in itertools.permutations(non_tlds):
    domain = "".join(permutation)
    for tld in tlds:
        domain_tld = domain + tld 
        try:
            socket.gethostbyname(domain_tld)
            print(domain_tld + ": taken")
        except:
            print(domain_tld + ": available")