Finding local IP addresses using Python's stdlib

I just found this but it seems a bit hackish, however they say tried it on *nix and I did on windows and it worked.

import socket
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
s.connect(("8.8.8.8", 80))
print(s.getsockname()[0])
s.close()

This assumes you have an internet access, and that there is no local proxy.

import socket
socket.gethostbyname(socket.gethostname())

This won't work always (returns 127.0.0.1 on machines having the hostname in /etc/hosts as 127.0.0.1), a paliative would be what gimel shows, use socket.getfqdn() instead. Of course your machine needs a resolvable hostname.

As an alias called myip:

alias myip="python -c 'import socket; print([l for l in ([ip for ip in socket.gethostbyname_ex(socket.gethostname())[2] if not ip.startswith(\"127.\")][:1], [[(s.connect((\"8.8.8.8\", 53)), s.getsockname()[0], s.close()) for s in [socket.socket(socket.AF_INET, socket.SOCK_DGRAM)]][0][1]]) if l][0][0])'"

• Works correctly with Python 2.x, Python 3.x, modern and old Linux distros, OSX/macOS and Windows for finding the current IPv4 address.
• Will not return the correct result for machines with multiple IP addresses, IPv6, no configured IP address or no internet access.
• Reportedly, this does not work on the latest releases of macOS.

NOTE: If you intend to use something like this within a Python program, the proper way is to make use of a Python module that has IPv6 support.

Same as above, but only the Python code:

import socket
print([l for l in ([ip for ip in socket.gethostbyname_ex(socket.gethostname())[2] if not ip.startswith("127.")][:1], [[(s.connect(('8.8.8.8', 53)), s.getsockname()[0], s.close()) for s in [socket.socket(socket.AF_INET, socket.SOCK_DGRAM)]][0][1]]) if l][0][0])

• This will throw an exception if no IP address is configured.

Version that will also work on LANs without an internet connection:

import socket
print((([ip for ip in socket.gethostbyname_ex(socket.gethostname())[2] if not ip.startswith("127.")] or [[(s.connect(("8.8.8.8", 53)), s.getsockname()[0], s.close()) for s in [socket.socket(socket.AF_INET, socket.SOCK_DGRAM)]][0][1]]) + ["no IP found"])[0])

(thanks @ccpizza)

Background:

Using socket.gethostbyname(socket.gethostname()) did not work here, because one of the computers I was on had an /etc/hosts with duplicate entries and references to itself. socket.gethostbyname() only returns the last entry in /etc/hosts.

This was my initial attempt, which weeds out all addresses starting with "127.":

import socket
print([ip for ip in socket.gethostbyname_ex(socket.gethostname())[2] if not ip.startswith("127.")][:1])

This works with Python 2 and 3, on Linux and Windows, but does not deal with several network devices or IPv6. However, it stopped working on recent Linux distros, so I tried this alternative technique instead. It tries to connect to the Google DNS server at 8.8.8.8 at port 53:

import socket
print([(s.connect(('8.8.8.8', 53)), s.getsockname()[0], s.close()) for s in [socket.socket(socket.AF_INET, socket.SOCK_DGRAM)]][0][1])

This method also works on the latest versions of macOS!

Then I combined the two above techniques into a one-liner that should work everywhere, and created the myip alias and Python snippet at the top of this answer.

With the increasing popularity of IPv6, and for servers with multiple network interfaces, using a third-party Python module for finding the IP address is probably both more robust and reliable than any of the methods listed here.

You can use the netifaces module. Just type:

pip install netifaces

in your command shell and it will install itself on default Python installation.

Then you can use it like this:

from netifaces import interfaces, ifaddresses, AF_INET
for ifaceName in interfaces():
    addresses = [i['addr'] for i in ifaddresses(ifaceName).setdefault(AF_INET, [{'addr':'No IP addr'}] )]
    print '%s: %s' % (ifaceName, ', '.join(addresses))

On my computer it printed:

{45639BDC-1050-46E0-9BE9-075C30DE1FBC}: 192.168.0.100
{D43A468B-F3AE-4BF9-9391-4863A4500583}: 10.5.9.207

Author of this module claims it should work on Windows, UNIX and Mac OS X.