Python - Get IP Address from Hostname

Python socket module gethostbyname() function accepts hostname argument and returns the IP address in the string format.

Here is a simple example in the Python interpreter to find out the IP address of some of the websites.

# python3.7
Python 3.7.3 (v3.7.3:ef4ec6ed12, Mar 25 2019, 16:52:21) 
[Clang 6.0 (clang-600.0.57)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> 
>>> import socket
>>> socket.gethostbyname('journaldev.com')
'45.79.77.230'
>>> socket.gethostbyname('google.com')
'172.217.166.110'
>>> 

Note: If the website is behind a load-balancer or working in the cloud, you might get a different result for the IP address lookup.

For example, try to run the above command for google.com or facebook.com. If you are not in the same location as mine (India), chances are that you will get a different IP address as output.

Let’s look at an example where we ask user to enter a website address and then print its IP address.

import socket

hostname = input("Please enter website address:\n")

# IP lookup from hostname
print(f'The {hostname} IP Address is {socket.gethostbyname(hostname)}')

Here is another example to pass the hostname as a command-line argument to the script. The script will find the IP address and print it.

import socket
import sys

# no error handling is done here, excuse me for that
hostname = sys.argv[1]

# IP lookup from hostname
print(f'The {hostname} IP Address is {socket.gethostbyname(hostname)}')

Output:

# python3.7 ip_address.py facebook.com
The facebook.com IP Address is 157.240.23.35

If the hostname doesn’t resolve to a valid IP address, socket.gaierror is raised. We can catch this error in our program using try-except block.

Here is the updated script with exception handling for invalid hostname.

import socket
import sys

hostname = sys.argv[1]

# IP lookup from hostname
try:
    ip = socket.gethostbyname(hostname)
    print(f'The {hostname} IP Address is {ip}')
except socket.gaierror as e:
    print(f'Invalid hostname, error raised is {e}')

Output:

# python3.7 ip_address.py jasjdkks.com               
Invalid hostname, error raised is [Errno 8] nodename nor servname provided, or not known
#

Reference: Socket Module API Docs