Palindrome Detection in DSA Python - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to check if a string is the same forwards and backwards.

DSA Python

def is_palindrome(s):
    return s == s[1]

Drag options to blanks, or click blank then click option'

A[::-1]

B[1:]

C[:1]

D[::-2]

Attempts:

3 left

💡 Hint

Common Mistakes

Using [1:] or [:1] which do not reverse the string.

Using [::-1] reverses the string, so comparing s to s[::-1] checks if it reads the same backwards.

2fill in blank

medium

Complete the code to ignore case when checking palindrome.

DSA Python

def is_palindrome(s):
    s = s.lower()
    return s == s[1]

Drag options to blanks, or click blank then click option'

A[1:]

B[::-1]

C[:1]

D[::2]

Attempts:

3 left

💡 Hint

Common Mistakes

Not reversing the string correctly after lowering case.

After converting to lowercase, reversing with [::-1] allows case-insensitive palindrome check.

3fill in blank

hard

Fix the error in the code to correctly check palindrome ignoring spaces.

DSA Python

def is_palindrome(s):
    s = s.replace(' ', '')
    return s == s[1]

Drag options to blanks, or click blank then click option'

A[::-1]

B[1:]

C[:1]

D[::2]

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect slicing that does not reverse the string.

Removing spaces and then reversing with [::-1] checks palindrome ignoring spaces.

4fill in blank

hard

Fill both blanks to create a palindrome check ignoring case and non-alphanumeric characters.

DSA Python

import re

def is_palindrome(s):
    s = re.sub([1], '', s).lower()
    return s == s[2]

Drag options to blanks, or click blank then click option'

A'[^a-zA-Z0-9]'

B' '

C[::-1]

D[1:]

Attempts:

3 left

💡 Hint

Common Mistakes

Removing only spaces instead of all non-alphanumeric characters.

Using wrong slice to reverse.

Using regex '[^a-zA-Z0-9]' removes all non-alphanumeric characters. Then reversing with [::-1] checks palindrome ignoring case and special characters.

5fill in blank

hard

Fill all three blanks to create a palindrome check ignoring case, spaces, and punctuation.

DSA Python

import string

def is_palindrome(s):
    s = ''.join(c for c in s.lower() if c not in [1])
    return s == s[2] and len(s) > [3]

Drag options to blanks, or click blank then click option'

Astring.punctuation + ' '

B[::-1]

C0

Dstring.whitespace

Attempts:

3 left

💡 Hint

Common Mistakes

Not removing all punctuation and spaces.

Using wrong slice to reverse.

Not checking string length.

Removing punctuation and spaces using string.punctuation + ' ', reversing with [::-1], and checking length greater than 0 ensures a valid palindrome check.