How to get IP address of host using Python

Python supports converting hostname or domain name to IP addresses without using an external program. The feature is provided by the gethostbyname function from the socket module.

gethostbyname outputs a single IP address for a given domain. If the host or domain has multiple IP addresses, you can use gethostbyname_ex(). gethostbyname_ex() returns the IP list as an array.

You can use gethostbyname and gethostbyname_ex() to resolve a hostname to IP address in Python by using the interactive shell or within a script.

1. Launch your favourite Python shell.

   $ ipython3
   Python 3.8.2 (default, Apr 27 2020, 15:53:34)
   Type 'copyright', 'credits' or 'license' for more information
   IPython 7.13.0 -- An enhanced Interactive Python. Type '?' for help.

2. Import socket module.

   In [1]: import socket

3. Get IP from hostname by calling socket.gethostbyname function with hostname as parameter .

   In [2]: socket.gethostbyname('www.google.com')
   Out[2]: '216.58.196.4'

   Hostname in this context refers to Fully Qualified Domain Name or FQDN.

   Use gethostbyname_ex() instead if the domain has multiple IP addresses.

4. Create a Python script that accepts hostname as parameter and outputs IP address such as the following.

   hostname-to-ip.py

   #!/usr/bin/env python3
    
   import socket
   import sys
    
   hostname = sys.argv[1]
   ip = socket.gethostbyname(hostname)
    
   print('Hostname: ', hostname, '\n' 'IP: ', ip)

5. Run the script from the command line with hostname as a parameter to test.

   $ python3 hostname-to-ip.py 'www.google.com'
   Hostname:  www.google.com
   IP:  172.217.31.68