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

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

Python Basics easy

Validate Password Strength

Implement a function that validates password strength based on clear rules.

strings validation conditions

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

Dicts & Sets easy

Revenue by Month

Write a function that groups a list of (date, amount) pairs by year-month and returns total revenue per month as a sorted dictionary.

dict aggregation sales

Data Structures & Algorithms easy

Delete Old Records

Filter a list of records by removing those with a date older than a given cutoff date.

filtering datetime lists

Decorators & Context Managers easy

Class-based decorator with call validation

Build a class-based decorator that validates a single argument's type and logs successful invocation.

decorators class 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

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

Datetime & Time Calculations easy

Format date output

Parse ISO date strings and format them into a friendly US-style date output.

datetime string-formatting date-parsing

Datetime & Time Calculations easy

Days Between Dates

Write a function that returns the number of days between two given dates.

datetime date-arithmetic calendar

Datetime & Time Calculations easy

Add Days to Date

Given a date in YYYY-MM-DD format and an integer number of days, return the resulting date in the same format.

datetime date arithmetic

Datetime & Time Calculations easy

Weekday from date

Write a function that returns the full English weekday name for a date string.

datetime date weekday

Datetime & Time Calculations easy

Leap Years in Range

Write a function that returns a list of all leap years between two given years, inclusive.

leap-year range datetime

Datetime & Time Calculations easy

Age in years months days

Given birth and reference dates, return age as a dictionary with years, months, days.

datetime date arithmetic age calculation

Datetime & Time Calculations easy

Time Difference HH:MM

Given two times in HH:MM format, return the absolute difference as a string in HH:MM format.

datetime time string

Datetime & Time Calculations easy

Unix timestamp to datetime

Write a function that returns a UTC datetime string from a Unix timestamp.

datetime unix-timestamp utc

Datetime & Time Calculations easy

Datetime to Unix timestamp

Parse a datetime string and convert it to a Unix timestamp assuming UTC.

datetime parsing timestamp

Datetime & Time Calculations easy

Business days between

Calculate the number of business days (Mon-Fri) between two dates, inclusive of both endpoints.

datetime weekdays date-arithmetic

Datetime & Time Calculations easy

Next Weekday Finder

Write a function that returns the next weekday date after a given date.

datetime date weekday

Datetime & Time Calculations easy

Previous Weekday Finder

Given a date, return the date of the immediately preceding weekday (Monday–Friday).

datetime date weekday

Datetime & Time Calculations easy

Quarter from date

Compute the quarter (1-4) for a date string like '2023-07-15'.

datetime date parsing

Showing 1–24 of 33 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.