Jump Search
Implement the jump search algorithm to locate a target in a sorted list, returning its index or -1.
Consecutive available seats
Given a list of seat statuses, return the length of the longest consecutive run of available (0) seats.
Argsort Indices
Implement a function that returns the indices that would sort a list of integers, with ties broken by original order.
Once Decorator: Run a Function Only Once
Implement a decorator that caches and returns the result of the first call for subsequent calls.
Print Args Decorator
Write a decorator that prints function name and arguments, then returns the original result.
Log Calls Decorator
Create a decorator that prints call details and returns the original result.
Safe Integer from String
Implement safe_int that converts a string to an integer, returning a default value on any failure, with support for an optional base.
Safe divide function
Implement safe_divide that returns None on ZeroDivisionError and TypeError.
Safe int parser
Implement safe_parse_int that converts a string to an int, returning a default value on failure.
Safe Float Parser
Write a function that safely converts a string to a float, returning None for invalid inputs.
Key error handler
Implement a safe dictionary access function that returns a default value on missing keys.
Else on try block
Implement a function that uses try-except-else to safely divide two numbers and return a result or error description.
Parse JSON safely
Implement a robust JSON string parser that returns a fallback on invalid input.
Exit handler registration
Write a function that registers a callback to run at interpreter exit and returns True on success.
Nth Triangular Number
Implement a function that returns the nth triangular number efficiently.
Integer Square Root Floor
Implement a function that returns the greatest integer whose square is ≤ n, using only integer operations.
Catalan number
Implement a function that returns the nth Catalan number using dynamic programming.
Sieve of Eratosthenes
Implement the Sieve of Eratosthenes to return a sorted list of all primes up to a given integer n.
Prime Factorization
Return a sorted list of prime factors of a positive integer, including repeated factors.
Sum of divisors
Given an integer n, return the sum of all its positive divisors.
Perfect Number Check
Write a function that returns True if a number is perfect, i.e., equal to the sum of its proper divisors.
Happy number check
Implement a function that returns True if a number is happy, False otherwise.
Triangular Number
Implement a function that returns the nth triangular number using the closed-form formula.
Pentagonal Number
Given a positive integer n, return the nth pentagonal number using the formula P(n) = n(3n - 1)/2.
Showing 145–168 of 255 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.