Logfile Search

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

import re

matched = []

log = open("Logfile.log")
log_duplicates = open("Logile_duplicate.log", "w")

for line in log:
    match = re.search(r'ERROR.+', line)
    if match:
       match_string = match.group()
       if not match_string in matched:
         print(match_string)
         matched.append(match_string)
         log_duplicates.write(match_string + "\n")

log.close()
log_duplicates.close()