How to get IP address of host using Python

Python offers native support for resolving hostnames or domain names to IP addresses using the socket module. This is essential for network programming, allowing scripts to interact with network resources efficiently. The primary functions for this are gethostbyname() and gethostbyname_ex().

gethostbyname() returns a single IP address for a given hostname. If the hostname has multiple IP addresses, use gethostbyname_ex() to retrieve all associated IP addresses. These functions are simple to use and integrate into Python scripts for tasks like logging and monitoring.

Python scripts can resolve hostnames both interactively and programmatically. This makes it a versatile tool for network-related tasks. Whether you're dealing with a single IP or a list, these functions provide the necessary capabilities to manage and interact with network systems effectively.

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