Mongo Log Parser to find open connections

mongolog.py

#!/usr/bin/env python

import sys
import logging
import datetime

def parse_connection(line):
    tokens = line.split()
    kind = 'OPEN' if "connection accepted from" in line else 'CLOSE'
    connection_id = tokens[9] if kind is 'OPEN'  \
                             else tokens[4][1:-1].replace('conn', '#')
    timestamp = datetime.datetime.strptime(' '.join(tokens[0:4]), '%a %b %d %H:%M:%S.%f')
    ip_address = tokens[8] if kind is 'OPEN' else tokens[7]

    return connection_id, timestamp, ip_address, kind

def calc_open_time(start, end):
    return end[1] - start[1]

def test():
    OPEN_CONNECTION = 'Wed Sep 17 11:17:19.163 [initandlisten] connection accepted from 192.0.0.1:123 #8841 (705 connections now open)'
    END_CONNECTION = 'Wed Sep 17 11:17:05.842 [conn8828] end connection 192.0.0.2:123 (704 connections now open)'
    assert parse_connection(END_CONNECTION) == ('#8828',
                                                 datetime.datetime(1900, 9, 17, 11, 17, 5, 842000),
                                                 '192.0.0.2:123',
                                                 'CLOSE')
    assert parse_connection(OPEN_CONNECTION) == ('#8841',
                                                datetime.datetime(1900, 9, 17, 11, 17, 19, 163000),
                                                '192.0.0.1:123',
                                                'OPEN')

    print "All tests completed successfully"

def main(show_time_open):
    open_connections = {}
    time_open = {}

    for num, line in enumerate(sys.stdin):
        try:
            key, timestamp, ip_address, kind = parse_connection(line)
        except:
            continue #Skip bad lines no matter what
        if kind is 'OPEN':
            if key in open_connections:
                logging.warning(key + ' in open connections already! ' + str(open_connections[key]))
            open_connections[key] = (timestamp, ip_address)

        else:
            if key not in open_connections:
                logging.info(key + ' not in open connections yet, skipping it')
                continue
            time_open[(key, timestamp, ip_address)] = timestamp - open_connections[key][0]
            del open_connections[key]
        sys.stderr.write('\r' + str(num))

    print "====================="
    for key, value in open_connections.items():
        print key, '|', str(value[0].time()), '|', value[1]
    print "====================="
   
if __name__ == '__main__':
    if len(sys.argv) > 1 and sys.argv[1] == 'test':
        test() 
    else:
        main(True)