python script for masquerading squid log

gistfile1.py

#coding=utf-8
import sys, json

users = {}
uid = 0
fn = open(sys.argv[1])
while True:
    line = fn.readline()
    if not line:break
    data = line.split()
    user = data[7]
    if user != '-':
        u2 = users.get(user)
        if not u2:
            u2 = 'u%i'%uid
            users[user] = u2
            uid +=1
        data[7] = u2
        print ' '.join(data)
    else:
        print line[:-1]
open('users.txt', 'w').write(json.dumps(users))