How to remove punctuation and capitalization in my palindrome assignment?

The problem is trying to use strings to prove whether a word or phrase is a palindrome.

def is_palindrome(input_string):

    left = 0

    right = len(input_string) - 1

    while left < right:
        if input_string[left] != input_string[right]:
            return False
        left += 1
        right -= 1
    
    return True 

This what I attempted to do but when typing in my_palindrome("race car") it was proven false when it is supposed to be proven true. Need help on finding code to add to this to make punctuation and capitalization negligible.