125. Valid Palindrome

Easy


A phrase is a palindrome if, after converting all uppercase letters into lowercase letters and removing all non-alphanumeric characters, it reads the same forward and backward. Alphanumeric characters include letters and numbers.

Given a string s, return true if it is a palindrome, or false otherwise.

 

Example 1:

Input: s = "A man, a plan, a canal: Panama"
Output: true
Explanation: "amanaplanacanalpanama" is a palindrome.

Example 2:

Input: s = "race a car"
Output: false
Explanation: "raceacar" is not a palindrome.

Example 3:

Input: s = " "
Output: true
Explanation: s is an empty string "" after removing non-alphanumeric characters.
Since an empty string reads the same forward and backward, it is a palindrome.

 

Constraints:

  • 1 <= s.length <= 2 * 105
  • s consists only of printable ASCII characters.




 import re
class Solution:
    def isPalindrome(self, s: str) -> bool:
        s = re.sub('[^a-zA-Z0-9]', '', s.lower())

        return s == s[::-1]


Random Note


  1. Effectively Using Django REST Framework Serializers
  2. How To Use DRF Serializers Effectively in Django
  3. My personal django rest framework serializer notes
  4. How to use DRF serializers effectively during write operations