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Python Coding
Challenges

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467 challenges 330 easy 120 medium 17 hard

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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

Python Basics easy

Leap Year Checker

Implement a function that decides whether a year is a leap year according to the standard Gregorian rules.

boolean conditionals date

Python Basics easy

Validate date format

Return True if input string is exactly YYYY-MM-DD and a real calendar date.

validation strings dates

Strings & Text easy

Validate time format

Check whether a given string is a valid 24-hour time in HH:MM format.

strings validation time

Strings & Text easy

Validate username format

Implement a function that validates a username according to length, allowed characters, and no consecutive underscores.

strings validation returns

Advanced Python hard

Validated descriptor

Implement a TypedField descriptor that raises TypeError if the value is not of the expected type.

descriptors OOP metaclass

Regular Expressions medium

Validate Email Regex

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

regex email validation

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

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

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

Regular Expressions easy

Validate Hex Color Code

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

regex validation strings

Datetime & Time Calculations easy

Days in month

Write a function that returns the number of days in a given month and year, correctly handling leap years.

datetime calendar leap-year

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.