Validate IP Address using RegEx in Python
Problem Statement: Write a Python program to validate if the given string is a valid IP address or not.
This is one of the questions asked in Juniper coding interview.
In Computer Network, the IP address uniquely defines each host or node in the network. You can read mode about IP address in Computer Networking.
Basically, this is a pattern matching problem where we can use a regular expression (RegEx).
IP Address Validation using Python RegEx
Here we are using the search method from the re module. You can find more detail in the Python RegEx tutorial.
Code
import re
regexIP = '''^(25[0-5]|2[0-4][0-9]|[0-1]?[0-9][0-9]?)\.(
25[0-5]|2[0-4][0-9]|[0-1]?[0-9][0-9]?)\.(
25[0-5]|2[0-4][0-9]|[0-1]?[0-9][0-9]?)\.(
25[0-5]|2[0-4][0-9]|[0-1]?[0-9][0-9]?)'''
def validateIP(strIP):
if(re.search(regexIP, strIP)):
print(f"{strIP} is a valid IP address.")
else:
print(f"{strIP} is an invalid IP address.")
if __name__ == '__main__' :
strIP = "122.134.3.123"
validateIP(strIP)
strIP = "44.235.34.1"
validateIP(strIP)
strIP = "277.13.23.17"
validateIP(strIP)
Output
122.134.3.123 is a valid IP address. 44.235.34.1 is a valid IP address. 277.13.23.17 is an invalid IP address.
Note: When we say IP address, by default its IPv4 address which is different from IPv6 address.
This is a simple program to validate IP address using regex in Python. Do you have any other solutions? Let me know in the comment. Thanks!
Comments
Rajat
It says it’s valid – 122.134.3.0991 is a valid IP address.
Can you test with this string – strIP = “122.134.3.0991”?
Aniruddha Chaudhari
Thanks for identifying it. Looks like we also have to check the length of each octave.
Malan
Just add $ in the end.
Aniruddha Chaudhari
Not sure where do you want to add $. The code is working. You can try executing code on our online CSEstack IDE.
Mallikarjuna
out = "10.10.10.40" part = out.split(".") if len(part) > 4: print("invalid") for i in part: if int(i) 255: print("invalid") if not isinstance(int(i),int): print("invalid") print("valid")Aniruddha Chaudhari
This is a truly simple and easy solution. Thanks for sharing. Here problem statement is to write the regex expression to check the valid IP address.