Practice Arena

Python Coding
Challenges

Write real Python in the browser. Instant feedback. From beginner to expert.

467 challenges 330 easy 120 medium 17 hard

All Easy Medium Hard

All Python Basics Strings & Text Lists & Arrays Dicts & Sets Functions & Closures OOP & Classes Data Structures & Algorithms Advanced Python Iterators & Generators Decorators & Context Managers Error Handling & Exceptions Regular Expressions Math & Number Theory Bit Manipulation Dynamic Programming Trees & Binary Trees Graphs & Graph Algorithms Recursion & Backtracking Greedy Algorithms Binary Search Two Pointers & Sliding Window Stacks & Queues Heaps & Priority Queues Linked Lists Matrix & 2D Arrays Datetime & Time Calculations Data Formats & Parsing SQL & SQLite Numpy & Vectorized Computing Cryptography & Hashing

Functions & Closures medium

Memoize decorator

Implement a @memoize decorator that caches results of a function.

decorators closures caching

Functions & Closures easy

Bind First Argument

Implement bind_first_arg, a decorator that fixes the first argument of any function.

decorators closures functions

Data Structures & Algorithms hard

LRU cache decorator

Implement @lru_cache(maxsize=N) for unary functions using OrderedDict.

decorators caching OrderedDict

Advanced Python medium

Retry decorator

Implement @retry(times=3) that retries a function on exception.

decorators error-handling

Decorators & Context Managers easy

Once Decorator: Run a Function Only Once

Implement a decorator that caches and returns the result of the first call for subsequent calls.

decorators closures caching

Decorators & Context Managers easy

Timing Decorator

Implement a decorator that prints the execution time of a function.

decorators time performance

Decorators & Context Managers medium

Memoize with TTL

Implement a decorator that caches function results for a limited time, returning cached values within the TTL and recomputing after expiry.

decorators memoization caching

Decorators & Context Managers medium

LRU Memoize

Implement an LRU memoization decorator that caches results for a fixed number of arguments.

decorators caching lru

Decorators & Context Managers medium

Cache result decorator

Create a decorator that stores results of function calls keyed by positional arguments.

decorators memoization functools

Decorators & Context Managers medium

Profile time decorator

Create a decorator that tracks how many times a function is called and its cumulative execution time.

decorators timing profiling

Decorators & Context Managers easy

Print Args Decorator

Write a decorator that prints function name and arguments, then returns the original result.

decorators functions wrappers

Showing 11 challenges

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.