Validate IPv4 Address

Problem

Return True if the string is a valid IPv4 address, and False otherwise.

An address has exactly four parts separated by dots, each part is one to three digits with no leading zeros unless it is exactly 0, and each numeric value is at most 255. The empty string is invalid.

Hint

Leading zeros are the classic trap, so check for them before the numeric range.

Test cases

case 1

in: ["192.168.1.1"]

expected: true

case 2

in: ["255.255.255.255"]

expected: true

case 3

in: ["256.1.1.1"]

expected: false

case 4

in: ["192.168.01.1"]

expected: false

case 5

in: ["1.1.1"]

expected: false

case 6

in: ["1.1.1.1.1"]

expected: false

Starter codePython

def valid_ipv4(s):
    # Your code here
    pass

6 test cases · run your code against them in the editor