Finding local IP addresses using Python's stdlib

Question

How can I find local IP addresses (i.e. 192.168.x.x or 10.0.x.x) in Python platform independently and using only the standard library?

Answer 1

On Linux:

>>> import socket, struct, fcntl
>>> sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
>>> sockfd = sock.fileno()
>>> SIOCGIFADDR = 0x8915
>>>
>>> def get_ip(iface = 'eth0'):
...     ifreq = struct.pack('16sH14s', iface, socket.AF_INET, '\x00'*14)
...     try:
...         res = fcntl.ioctl(sockfd, SIOCGIFADDR, ifreq)
...     except:
...         return None
...     ip = struct.unpack('16sH2x4s8x', res)[2]
...     return socket.inet_ntoa(ip)
... 
>>> get_ip('eth0')
'10.80.40.234'
>>>