Practice Arena

Python Coding
Challenges

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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

Strings & Text easy

Kebab Case a Phrase

Implement a function that converts a phrase into lowercase kebab-case, handling spaces, punctuation, and camelCase.

strings case-conversion regex

Strings & Text easy

Stack Trace Sanitizer

Implement a function that rewrites traceback file paths to basenames only.

strings regex parsing

Strings & Text easy

Extract Hashtags

Extract unique hashtags from a given text string in the order they appear.

strings parsing hashtags

Strings & Text easy

Extract mentions

Extract unique @mentions from a string, respecting email-like patterns and punctuation.

strings parsing sets

Strings & Text easy

Remove HTML tags

Remove all HTML tags from a string to extract clean text.

html string parsing

Strings & Text easy

Find all numbers in text

Write a function that extracts all standalone integers from a text string using regular expressions.

regex parsing numbers

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 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

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

Regular Expressions easy

Multiline anchor match

Extract lines beginning with a plain-text prefix from multiline strings using Python's re module.

regex anchors multiline

Regular Expressions easy

Lookahead Validation

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

regex lookahead validation

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

Regular Expressions easy

Match scientific notation

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

regex validation scientific-notation

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

Regular Expressions easy

Named group extraction

Parse a log line into structured fields using named groups and re.match.

regex named-groups parsing

Data Formats & Parsing easy

Parse Apache log line

Write a function that parses a single Apache access log line into a dictionary with IP, timestamp, request, status, and size.

parsing strings regex

Showing 1–19 of 19 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.