with open(filename) as data:

    accounts = dict()

    for line in data:
        username = line.split()[1]
        IP = line.split()[0]

        try:
            accounts[username].add(IP)
        except KeyError:
            accounts[username] = set()
            accounts[username].add(IP)

print "The accounts will be deleted from memory in 5 seconds"
time.sleep(5)
accounts.clear()

print "The accounts have been deleted from memory"
time.sleep(5)

print "End of script"

accounts = dict()
data= open(filename)
for line in data.readline():
    info = line.split("LOG:")
    if len(info) == 2 :
        ( a , b ) = info
        try:
            accounts[a].add(True)
        except KeyError:
            accounts[a] = set()
            accounts[a].add(True)

import random

fn = random.randint

with open('ips.txt', 'w') as f:
    for i in xrange(9000000):
        f.write('{0}.{1}.{2}.{3} username-{4}n'.format(
            fn(0,255),
            fn(0,255),
            fn(0,255),
            fn(0,255),
            fn(0, 9000000),
        ))

import time
from collections import defaultdict

def read_file(filename):
    with open(filename) as data:

        accounts = defaultdict(set)

        for line in data:
            IP, username = line.split()[:2]
            accounts[username].add(IP)

    print "The accounts will be deleted from memory in 5 seconds"
    time.sleep(5)
    accounts.clear()

    print "The accounts have been deleted from memory"
    time.sleep(5)

    print "End of script"

if __name__ == '__main__':
    read_file('ips.txt')