Introduction

An IP address consists of numbers and characters. There are two versions of IP address: IPv4 and IPv6. The task is to validate the given IP address using regex expression.

Program

import re
def check_IP(ip_IP):
# Regular expression for IPv4and IPv6
    re_IPv4 = "(([0-9]|[1-9][0-9]|1[0-9][0-9]|"\
            "2[0-4][0-9]|25[0-5])\\.){3}"\
            "([0-9]|[1-9][0-9]|1[0-9][0-9]|"\
            "2[0-4][0-9]|25[0-5])"
    re_IPv6 = "((([0-9a-fA-F]){1,4})\\:){7}"\
             "([0-9a-fA-F]){1,4}"
     
    exp_IPv4 = re.compile(re_IPv4)
    exp_IPv6 = re.compile(re_IPv6)
    if (re.search(exp_IPv4, ip_IP)):
        print("The given input is a valid IPv4!")
    elif (re.search(exp_IPv6, ip_IP)):
        print("The given input is a valid IPv6!")
    return "The given input is a invalid IP!"
ip_IP= input("Enter the IP address to validate:")
check_IP(ip_IP)

Output

Explanation

In the above python code, we have passed the regular expression for IPv4 and IPv6 in search() method along with the input string. If the regex pattern (of  IPv4 and IPv6) matches with the input string, the output “valid” is returned otherwise the output “invalid” is returned.