Convert an IP string to a number and vice versa

How would I use python to convert an IP address that comes as a str to a decimal number and vice versa?

For example, for the IP 186.99.109.000 <type'str'>, I would like to have a decimal or binary form that is easy to store in a database, and then retrieve it.

Answer

converting an IP string to long integer:

import socket, struct

def ip2long(ip):
    """
    Convert an IP string to long
    """
    packedIP = socket.inet_aton(ip)
    return struct.unpack("!L", packedIP)[0]

the other way around:

>>> socket.inet_ntoa(struct.pack('!L', 2130706433))
'127.0.0.1'