Practice Arena

Python Coding Challenges

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

925 challenges 556 easy 323 medium 46 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
Decorators & Context Managers easy

Print Args Decorator

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

decorators functions wrappers
+10 pts 10m
Decorators & Context Managers easy

Count calls decorator

Implement a decorator that counts and reports how many times the wrapped function is called.

decorator closure function
+10 pts 15m
Decorators & Context Managers easy

Log Calls Decorator

Create a decorator that prints call details and returns the original result.

decorators logging function-wrappers
+10 pts 15m
Decorators & Context Managers medium

Benchmark decorator

Implement a benchmarking decorator that records call count and timing statistics per function.

decorators timing functools
+25 pts 25m
Error Handling & Exceptions easy

Safe divide function

Implement safe_divide that returns None on ZeroDivisionError and TypeError.

try-except division error-handling
+8 pts 10m
Error Handling & Exceptions easy

Safe Float Parser

Write a function that safely converts a string to a float, returning None for invalid inputs.

float exception parsing
+10 pts 10m
Error Handling & Exceptions easy

Divide with zero check

Write a function that safely divides two numbers, catching division by zero.

exceptions division error-handling
+8 pts 10m
Error Handling & Exceptions easy

Key error handler

Implement a safe dictionary access function that returns a default value on missing keys.

exceptions dict fallback
+8 pts 10m
Error Handling & Exceptions easy

Else on try block

Implement a function that uses try-except-else to safely divide two numbers and return a result or error description.

exception-handling try-except-else division
+8 pts 10m
Error Handling & Exceptions easy

Exit handler registration

Write a function that registers a callback to run at interpreter exit and returns True on success.

atexit exceptions cleanup
+8 pts 12m
Regular Expressions medium

Validate Email Regex

Implement a function that validates email addresses using regex with specific rules.

regex email validation
+20 pts 25m
Regular Expressions easy

Validate phone number

Write a function that uses regular expressions to determine if a given string is a valid US phone number.

regex validation phone
+10 pts 15m
Regular Expressions easy

Match IPv4 Address

Write a function that uses a regular expression to check if a string is a valid IPv4 address.

regex validation ipv4
+8 pts 12m
Regular Expressions hard

Match IPv6 Address

Write a function that uses a regex to validate whether a string is a fully expanded IPv6 address.

regex validation ipv6
+25 pts 30m
Regular Expressions medium

Match Credit Card Pattern

Write a function that validates a credit card number string against a set of formatting rules.

regex validation credit-card
+25 pts 25m
Regular Expressions easy

Validate Hex Color Code

Write a function that validates hex color codes using regular expressions.

regex validation strings
+10 pts 10m
Regular Expressions easy

Lookahead Validation

Write a regex-based function to check if a password meets length and character class requirements.

regex lookahead validation
+8 pts 10m
Regular Expressions easy

Match Balanced Parentheses with Regex

Write a function that uses regular expressions to determine if parentheses are balanced and properly nested.

regex strings validation
+10 pts 15m
Regular Expressions easy

Match scientific notation

Implement a function that checks if a string is in valid scientific notation.

regex validation scientific-notation
+10 pts 15m
Regular Expressions easy

Non-greedy quantifier

Implement a function that uses a non-greedy regex to extract the shortest substring between two delimiters.

regex lazy quantifier string parsing
+8 pts 10m
Math & Number Theory easy

Nth Triangular Number

Implement a function that returns the nth triangular number efficiently.

math formula integers
1
+10 pts 10m
Math & Number Theory easy

Integer Square Root Floor

Implement a function that returns the greatest integer whose square is ≤ n, using only integer operations.

math binary-search integer
+8 pts 12m
Math & Number Theory easy

Catalan number

Implement a function that returns the nth Catalan number using dynamic programming.

math dynamic-programming combinatorics
+10 pts 15m
Math & Number Theory easy

Stirling number

Implement a function to compute Stirling numbers of the second kind S(n,k).

stirling-numbers dynamic-programming combinatorics
+10 pts 15m

Showing 217–240 of 365 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

  1. Pick a category — basics, algorithms, strings, and more
  2. Open a challenge, read the statement, and edit the starter code
  3. 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.