Coding for Strings and Palindromes | Dataford Interview Questions

The TD mobile banking app receives reference strings that may contain letters, digits, spaces, and punctuation. Write a function that determines whether the reference reads the same forward and backward after ignoring non-alphanumeric characters and letter case.

Return True when the normalized string is a palindrome; otherwise, return False.

Formal Specification

Input: s, a string containing printable ASCII characters.
Output: A Boolean indicating whether s is a palindrome after normalization.
Normalization keeps only characters for which str.isalnum() is true and compares letters without regard to case.

Constraints

1 <= len(s) <= 2 * 10^5
s contains printable ASCII characters
Comparison is case-insensitive
Non-alphanumeric characters are ignored

Function Signature

def is_palindrome(s):

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