if_nametoindex, if_indextoname functions for python 2.x. In python 3.x, they are available in socket module.

if_nametoindex, if_indextoname.py

import ctypes
import ctypes.util

libc = ctypes.CDLL(ctypes.util.find_library('c'))

def if_nametoindex (name):
    if not isinstance (name, str):
        raise TypeError ('name must be a string.')
    ret = libc.if_nametoindex (name)
    if not ret:
        raise RunTimeError ("Invalid Name")
    return ret

def if_indextoname (index):
    if not isinstance (index, int):
        raise TypeError ('index must be an int.')
    libc.if_indextoname.argtypes = [ctypes.c_uint32, ctypes.c_char_p]
    libc.if_indextoname.restype = ctypes.c_char_p

    ifname = ctypes.create_string_buffer (32)
    ifname = libc.if_indextoname (index, ifname)
    if not ifname:
        raise RuntimeError ("Inavlid Index")
    return ifname

Exactly what I needed. Thanks! This is now included in socket since Python 3.3 but is not available in 2.7.