Pegando o endereço ip no python

>>> import netifaces
>>> netifaces.interfaces()
['lo0', 'gif0', 'stf0', 'en0', 'en1', 'fw0']
>>> netifaces.ifaddresses('en0')
{18: [{'addr': '00:12:34:56:78:9a'}], 2: [{'broadcast':
 '10.255.255.255', 'netmask': '255.0.0.0', 'addr': '10.16.1.4'}],
 30: [{'netmask': 'ffff:ffff:ffff:ffff::', 'addr':
 'fe80::123:4567:89ab:cdef%en0'}]}

# outro exemplo
python

s.getsockname()
Python 2.5.2 (r252:60911, Apr 21 2008, 11:12:42)
[GCC 4.2.3 (Ubuntu 4.2.3-2ubuntu7)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import netifaces
>>> netifaces.ifaddresses('eth0')[2][0]['addr']
'192.168.0.31'
>>>

# usando a biblioteca socket
import socket

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

s.connect(("www.google.com",80))

# agora o ip externo
import urllib2
pub_ip = urllib2.urlopen("http://whatismyip.com/automation/n09230945.asp").read()
print pub_ip