FizzBuzz, precisely
Return a newline-separated string for 1..n: Fizz, Buzz, FizzBuzz, or the number.
Temperature converter
Convert Celsius to Fahrenheit: F = C × 9/5 + 32.
Even or odd?
Return 'even' or 'odd' for an integer.
Sum of digits
Return the sum of all decimal digits of a non-negative integer.
Collatz steps
Count how many steps the Collatz sequence takes to reach 1 from n.
Factorial (iterative)
Compute n! iteratively without recursion.
Power of two?
Return True if n is an exact power of 2.
GCD via Euclid
Compute the greatest common divisor of two positive integers.
Prime checker
Return True if n is a prime number.
Compound interest
Return the future balance after compound interest, rounded to two decimals.
Reverse a string
Return the characters of the string in reverse order.
Palindrome check
Return True if the string reads the same forwards and backwards (ignoring case and non-alphanumeric).
Count vowels
Count the number of vowels (a, e, i, o, u) in a string (case-insensitive).
Title case converter
Return the string with each word capitalised.
Anagram check
Return True if two strings are anagrams of each other.
Two Sum
Return indices (i, j) with i < j such that nums[i] + nums[j] == target.
Remove duplicates (sorted)
Return a sorted list with duplicates removed.
Merge two sorted arrays
Merge two sorted arrays into one sorted array.
Word frequency
Return a dict mapping each word to its count in the sentence.
List intersection
Return the sorted list of elements common to both lists.
First non-repeating character
Find the index of the first character that appears only once.
Most frequent element
Return the element that appears most often in a list.
Stack class
Implement a Stack class with push, pop, peek, is_empty, and size.
Valid parentheses
Return True if brackets in the string close in the correct order.
Binary search
Return the index of target in a sorted list, or -1 if not present.
Infinite counter generator
Create an infinite counter starting from `start`, stepping by `step`.
Showing 26 challenges · easy
Guide: free Python coding challenges
Practice Python by solving problems
PythonSkillset challenges are hands-on coding exercises from beginner to advanced. Open a challenge, read the problem, write Python in the split-pane editor, and run tests with Pyodide — no install required.
How to use the arena
- Pick a category — basics, algorithms, strings, and more
- Open a challenge, read the statement, and edit the starter code
- Run tests, fix failures, then try a related quiz or tutorial lesson
Challenges vs tutorials and quizzes
Challenges test what you can build under constraints. For guided teaching, use our Python tutorials. For quick checks, try quizzes or copy snippets from code samples.