Parse Apache access logs

parse_apache_access.py

import re
from urllib.parse import parse_qs

regex = re.compile('^(?P<ip>\S+)\s+-\s*(?P<userid>\S+)\s+\[(?P<datetime>[^\]]+)\]\s+"(?P<method>[A-Z]+)\s*(?P<request>[^ "]+)?\s*(HTTP/(?P<http_version>[0-9.]+))?"\s+(?P<status>[0-9]{3})\s+(?P<size>[0-9]+|-)\s+"(?P<referer>[^"]*)"\s+"(?P<user_agent>[^"]*)"')

def parse_log(log):
    res = regex.match(line)
    if not res:
        raise(ValueError('Invalid log format'))
    res = res.groupdict()
    if res['request']:
        if '?' in res['request']:
            l = res['request'].find('?')
            res['path'] = res['request'][:l]
            res['query'] = parse_qs(res['request'][l:])
        else:
            res['path'] = res['request']
            res['query'] = {}
    return res

Not perfect, does not handle IPv6 and invalid urls with spaces