String Exercises
3 min read ·
These exercises are designed to deeply test your understanding of Python strings.
They focus on logic, slicing, methods, formatting, and edge cases.
Exercise 1: Reverse Words, Not Sentence
Problem:
Reverse each word in a string, but keep the word order the same.
Input
Expected Output
Exercise 2: Count Vowels and Consonants
Problem:
Count the number of vowels and consonants in a string.
Input
Expected Output
Exercise 3: Check Palindrome (Ignore Case & Spaces)
Problem:
Check whether a string is a palindrome.
Ignore spaces and case sensitivity.
Input
Expected Output
Exercise 4: Remove Duplicate Characters
Problem:
Remove duplicate characters from a string while keeping the first occurrence.
Input
Expected Output
Exercise 5: Longest Word in a Sentence
Problem:
Find the longest word in a sentence.
Input
Expected Output
Exercise 6: Character Frequency Dictionary
Problem:
Create a dictionary that stores the frequency of each character (ignore spaces).
Input
Expected Output
Exercise 7: Mask Sensitive Information
Problem:
Mask all characters of a string except the last 4 characters.
Input
Expected Output
Exercise 8: Capitalize Every Alternate Word
Problem:
Capitalize every alternate word in a sentence.
Input
Expected Output
Exercise 9: Extract Domain from Email
Problem:
Extract the domain name from an email address.
Input
Expected Output
Exercise 10: Check Anagram Strings
Problem:
Check if two strings are anagrams (ignore spaces and case).
Input
Expected Output
Exercise 11: Compress the String
Problem:
Compress the string by counting consecutive characters.
Input
Expected Output
Exercise 12: Find First Non-Repeating Character
Problem:
Find the first non-repeating character in a string.
Input
Expected Output
Exercise 13: Validate Password Strength
Problem:
Check if a password:
- Has at least 8 characters
- Contains uppercase, lowercase, digit, and special character
Input
Expected Output
Exercise 14: Remove Special Characters
Problem:
Remove all special characters from a string.
Input
Expected Output
Exercise 15: Rotate String
Problem:
Rotate a string to the left by
n characters.Input
Expected Output
Final Challenge
Problem:
Given a sentence, return the word with:
- Highest vowel count
- If tie, return the first one
Input
Expected Output
Note for Learners
Hard-Level Insight
If you can solve these exercises without looking at solutions, your string concepts are interview-ready.