How do check for a palindrome in Python?

Question

I am given word and I have to check if the word is a palindrome. My program works well until I play around with the case of the word.

def isPalindrome(word):
    reversedWord = word[::-1]
    palindrome = true
    for n in range(len(word)):
        if(word[n] != reversedWord[i])
            palindrome = false
    return palindrome

I tried the below code and it works well if I feed the function the word "mom", however it fails when I give it the same word but with a different case "Mom"

def isPalindrome(word):
    reversedWord = word[::-1]
    palindrome = true
    for n in range(len(word)):
        if(word[n] != reversedWord[i])
            palindrome = false
    return palindrome

Does this answer your question? [How to check for palindrome using Python logic](https://stackoverflow.com/questions/17331290/how-to-check-for-palindrome-using-python-logic) — cafce25, Nov 14 '22 at 11:46

hash · Answer 1 · 2022-11-14T11:52:49.723

1

You are already reversing the string. Just return reversedWord.lower() == word.lower() instead of checking character by character.

edited Nov 14 '22 at 11:52

answered Nov 14 '22 at 11:50

hash

82
7

score 1 · Answer 2 · answered Nov 14 '22 at 11:53

1

You need to normalise the string to either upper- or lower-case.

def isPalindrome(word):
  word = word.lower()
  return word == word[::-1]

answered Nov 14 '22 at 11:53

DarkKnight

19,739
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score 1 · Answer 3 · answered Nov 14 '22 at 12:00

1

The simplest form to this is where you use Ternary operator and Python String lower() method as given below:

def isPalindrome(word):
    return True if (word.lower() == word[::-1].lower()) else False

answered Nov 14 '22 at 12:00

Jyothis - Intel

319
1
5

You don't need a ternary operator here. `return True if x else False` is the same as `return x` – Yevhen Kuzmovych Nov 14 '22 at 12:57

jacksc0tt · Answer 4 · 2022-11-14T11:49:21.203

0

You would have to compare the lowercase version of the word to its reversed version. There is a function in Python that transforms a String to all-lowercase. Search for it and try it out :)

edited Nov 14 '22 at 11:49

answered Nov 14 '22 at 11:48

jacksc0tt

11
4

score 0 · Answer 5 · answered Nov 14 '22 at 11:49

0

The hex values of m and M in ascii table are different from each other. Since these values are different in logic comparison, the result will be not a polydrome.

answered Nov 14 '22 at 11:49

askinmert

1
1

score 0 · Answer 6 · answered Nov 14 '22 at 11:51

0

You could transform your word into lowercase (or uppercase) and then check if the reversed if it is a palindrome.

def isPalindrome(word):
    word = word.lower()
    return True if word == word[::-1] else False

isPalindrom("Mom") returns True

answered Nov 14 '22 at 11:51

Timo

357
1
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`return word == word[::-1]` is equivalent to `return True if word == word[::-1] else False` – Yevhen Kuzmovych Nov 14 '22 at 11:51

How do check for a palindrome in Python?

6 Answers6