getMissing.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-

set1 = open('set1.txt','r')
set2 = open('set2.txt','r')
output = open('diff.txt','w')

eachhost1 = set1.read().splitlines()
#print eachhost1
eachhost2 = set2.read().splitlines()
#print eachhost2

for host2 in eachhost2:
  if host2 in eachhost1:
  	print "Matched with: "+host2
  else:
  	domain = "domain:"+host2+"\n"
  	output.write(domain)
set1.close()
set2.close()
output.close()