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])

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.

im using following module:

#!/usr/bin/python
# module for getting the lan ip address of the computer

import os
import socket

if os.name != "nt":
    import fcntl
    import struct
    def get_interface_ip(ifname):
        s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
        return socket.inet_ntoa(fcntl.ioctl(
                s.fileno(),
                0x8915,  # SIOCGIFADDR
                struct.pack('256s', bytes(ifname[:15], 'utf-8'))
                # Python 2.7: remove the second argument for the bytes call
            )[20:24])

def get_lan_ip():
    ip = socket.gethostbyname(socket.gethostname())
    if ip.startswith("127.") and os.name != "nt":
        interfaces = ["eth0","eth1","eth2","wlan0","wlan1","wifi0","ath0","ath1","ppp0"]
        for ifname in interfaces:
            try:
                ip = get_interface_ip(ifname)
                break;
            except IOError:
                pass
    return ip

Tested with windows and linux (and doesnt require additional modules for those) intended for use on systems which are in a single IPv4 based LAN.

The fixed list of interface names does not work for recent linux versions, which have adopted the systemd v197 change regarding predictable interface names as pointed out by Alexander. In such cases, you need to manually replace the list with the interface names on your system, or use another solution like netifaces.

[Windows only] If you don't want to use external packages and don't want to rely on outside Internet servers, this might help. It's a code sample that I found on Google Code Search and modified to return required information:

def getIPAddresses():
    from ctypes import Structure, windll, sizeof
    from ctypes import POINTER, byref
    from ctypes import c_ulong, c_uint, c_ubyte, c_char
    MAX_ADAPTER_DESCRIPTION_LENGTH = 128
    MAX_ADAPTER_NAME_LENGTH = 256
    MAX_ADAPTER_ADDRESS_LENGTH = 8
    class IP_ADDR_STRING(Structure):
        pass
    LP_IP_ADDR_STRING = POINTER(IP_ADDR_STRING)
    IP_ADDR_STRING._fields_ = [
        ("next", LP_IP_ADDR_STRING),
        ("ipAddress", c_char * 16),
        ("ipMask", c_char * 16),
        ("context", c_ulong)]
    class IP_ADAPTER_INFO (Structure):
        pass
    LP_IP_ADAPTER_INFO = POINTER(IP_ADAPTER_INFO)
    IP_ADAPTER_INFO._fields_ = [
        ("next", LP_IP_ADAPTER_INFO),
        ("comboIndex", c_ulong),
        ("adapterName", c_char * (MAX_ADAPTER_NAME_LENGTH + 4)),
        ("description", c_char * (MAX_ADAPTER_DESCRIPTION_LENGTH + 4)),
        ("addressLength", c_uint),
        ("address", c_ubyte * MAX_ADAPTER_ADDRESS_LENGTH),
        ("index", c_ulong),
        ("type", c_uint),
        ("dhcpEnabled", c_uint),
        ("currentIpAddress", LP_IP_ADDR_STRING),
        ("ipAddressList", IP_ADDR_STRING),
        ("gatewayList", IP_ADDR_STRING),
        ("dhcpServer", IP_ADDR_STRING),
        ("haveWins", c_uint),
        ("primaryWinsServer", IP_ADDR_STRING),
        ("secondaryWinsServer", IP_ADDR_STRING),
        ("leaseObtained", c_ulong),
        ("leaseExpires", c_ulong)]
    GetAdaptersInfo = windll.iphlpapi.GetAdaptersInfo
    GetAdaptersInfo.restype = c_ulong
    GetAdaptersInfo.argtypes = [LP_IP_ADAPTER_INFO, POINTER(c_ulong)]
    adapterList = (IP_ADAPTER_INFO * 10)()
    buflen = c_ulong(sizeof(adapterList))
    rc = GetAdaptersInfo(byref(adapterList[0]), byref(buflen))
    if rc == 0:
        for a in adapterList:
            adNode = a.ipAddressList
            while True:
                ipAddr = adNode.ipAddress
                if ipAddr:
                    yield ipAddr
                adNode = adNode.next
                if not adNode:
                    break

Usage:

>>> for addr in getIPAddresses():
>>>    print addr
192.168.0.100
10.5.9.207

As it relies on windll, this will work only on Windows.

For linux, you can just use check_output of the hostname -I system command like so:

from subprocess import check_output
check_output(['hostname', '-I'])

I'm afraid there aren't any good platform independent ways to do this other than connecting to another computer and having it send you your IP address. For example: findmyipaddress. Note that this won't work if you need an IP address that's behind NAT unless the computer you're connecting to is behind NAT as well.

Here's one solution that works in Linux: get the IP address associated with a network interface.

FYI I can verify that the method:

import socket
addr = socket.gethostbyname(socket.gethostname())

Works in OS X (10.6,10.5), Windows XP, and on a well administered RHEL department server. It did not work on a very minimal CentOS VM that I just do some kernel hacking on. So for that instance you can just check for a 127.0.0.1 address and in that case do the following:

if addr == "127.0.0.1":
     import commands
     output = commands.getoutput("/sbin/ifconfig")
     addr = parseaddress(output)

And then parse the ip address from the output. It should be noted that ifconfig is not in a normal user's PATH by default and that is why I give the full path in the command. I hope this helps.

Well you can use the command "ip route" on GNU/Linux to know your current IP address.

This shows the IP given to the interface by the DHCP server running on the router/modem. Usually "192.168.1.1/24" is the IP for local network where "24" means the range of posible IP addresses given by the DHCP server within the mask range.

Here's an example: Note that PyNotify is just an addition to get my point straight and is not required at all

#! /usr/bin/env python

import sys , pynotify

if sys.version_info[1] != 7:
   raise RuntimeError('Python 2.7 And Above Only')       

from subprocess import check_output # Available on Python 2.7+ | N/A 

IP = check_output(['ip', 'route'])
Split_Result = IP.split()

# print Split_Result[2] # Remove "#" to enable

pynotify.init("image")
notify = pynotify.Notification("Ip", "Server Running At:" + Split_Result[2] , "/home/User/wireless.png")    
notify.show()    

The advantage of this is that you don't need to specify the network interface. That's pretty useful when running a socket server

You can install PyNotify using easy_install or even Pip:

easy_install py-notify

or

pip install py-notify

or within python script/interpreter

from pip import main

main(['install', 'py-notify'])

Yet another variant to previous answers, can be saved to an executable script named my-ip-to:

#!/usr/bin/env python

import sys, socket

if len(sys.argv) > 1:
    for remote_host in sys.argv[1:]:
        # determine local host ip by outgoing test to another host
        # use port 9 (discard protocol - RFC 863) over UDP4
        with socket.socket(socket.AF_INET, socket.SOCK_DGRAM) as s:
            s.connect((remote_host, 9))
            my_ip = s.getsockname()[0]
            print(my_ip, flush=True)
else:
    import platform

    my_name = platform.node()
    my_ip = socket.gethostbyname(my_name)
    print(my_ip)

it takes any number of remote hosts, and print out local ips to reach them one by one:

$ my-ip-to z.cn g.cn localhost
192.168.11.102
192.168.11.102
127.0.0.1
$

And print best-bet when no arg is given.

$ my-ip-to
192.168.11.102

For a linux env, read the /proc/net/tcp, the second (localaddress) and third (remoteaddress) will give the IPs at hexa format.

Tip: If second column is zeroed (00000000:0000) so its a Listen Port :)

https://github.com/romol0s/python/blob/master/general/functions/getTcpListenIpsByPort.py

https://www.kernel.org/doc/Documentation/networking/proc_net_tcp.txt

Windows solution, Take it or leave it.

gets only the self ip, on the current active wlan[wireless LAN] ie the computer's ip on the (wifi router or network switch).

note: its not the public ip of the device and does not involve any external requests or packages or public apis.

The core idea is to parse the output of shell command: ipconfig, or ifconfig on linux. we are using subprocess to acquire the output.

def wlan_ip():
    import subprocess
    result=subprocess.run('ipconfig',stdout=subprocess.PIPE,text=True).stdout.lower()
    scan=0
    for i in result.split('\n'):
        if 'wireless' in i: #use "wireless" or wireless adapters and "ethernet" for wired connections
            scan=1
        if scan:
            if 'ipv4' in i:
                return i.split(':')[1].strip()
print(wlan_ip())

this is what happens after CMD:'ipconfig' :

we get this output, we captured it in python using subprocess output.

C:\Users\dell>ipconfig

Wireless LAN adapter Wi-Fi:

   Connection-specific DNS Suffix  . :
   Link-local IPv6 Address . . . . . : fe80::f485:4a6a:e7d5:1b1c%4
   IPv4 Address. . . . . . . . . . . : 192.168.0.131
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
   Default Gateway . . . . . . . . . : 192.168.0.1

and we parsed the string in python, in a manner that selects the wireless adapter's ip on current network.

You can do this easily on modern *NIX systems that have the iproute2 utility by calling it via subprocess.run() as you can output in JSON with the -j switch and then use the json.loads() module and method to convert that to a python data structure. The following code displays the first non loopback IP address.

import subprocess
import json

ip = json.loads(subprocess.run('ip -j a'.split(),capture_output=True).stdout.decode())[1]['addr_info'][0]['local'] 

print(ip)

Alternativly if you had multiple IP's and wanted to find the IP that would be used to connect to a specific destination you could use ip -j route get 8.8.8.8 like this:

import subprocess 
import json 

ip = json.loads(subprocess.run('ip -j route get 8.8.8.8'.split(),capture_output=True).stdout.decode())[0]['prefsrc']

print(ip)

If your looking for all IP addresses you can iterate through the list of dictionaries returned by ip -j a

import subprocess
import json

list_of_dicts = json.loads(subprocess.run('ip -j a'.split(),capture_output=True).stdout.decode())

for interface in list_of_dicts:
    try:print(f"Interface: {interface['ifname']:10} IP: {interface['addr_info'][0]['local']}")
    except:pass

pyroute2 is a great library that can be used to obtain not just ip addresses but also gateway information and other useful information. The following code can obtain the ipv4 address of any interface.

from pyroute2 import IPRoute
ip = IPRoute()

def get_ipv4_address(intf):
    return dict(ip.get_addr(label=intf)[0]['attrs'])['IFA_LOCAL']

print(get_ipv4_address('eth0'))

Simple yet sweet!

def getip():

    import socket
    hostname= socket.gethostname()
    ip=socket.gethostbyname(hostname)

    return(ip)

@fatal_error solution should be the accepted answer! this is an implementation of his solution in nodejs in case people need it:

const dgram = require('dgram');

async function get_local_ip() {
    const s = new dgram.createSocket('udp4');
    return new Promise((resolve, reject) => {
        try {
            s.connect(1, '8.8.8.8', function () {
                const ip = s.address();
                s.close();
                resolve(ip.address)
            });
        } catch (e) {
            console.error(e);
            s.close();
            reject(e);
        }
    })
}