mac address <=> integer conversions in python

macaddr.py

import re

def mac_to_int(mac):
    res = re.match('^((?:(?:[0-9a-f]{2}):){5}[0-9a-f]{2})$', mac.lower())
    if res is None:
        raise ValueError('invalid mac address')
    return int(res.group(0).replace(':', ''), 16)

def int_to_mac(macint):
    if type(macint) != int:
        raise ValueError('invalid integer')
    return ':'.join(['{}{}'.format(a, b)
                     for a, b
                     in zip(*[iter('{:012x}'.format(macint))]*2)])

Without any error checking:

import re

def mac_to_int(mac):
    return int(mac.replace(":", ""), 16)

def int_to_mac(macint):
    return  ":".join(re.findall("..", "%012x"%macint))