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

Datetime & Time Calculations easy

Week Number ISO

Given a date, return its ISO 8601 week number (1–53) without using datetime.isocalendar().

datetime iso date

Datetime & Time Calculations easy

Duration Human Readable

Write a function that turns a number of seconds into a human-readable duration like '2 hours, 1 minute'.

datetime strings formatting

Datetime & Time Calculations easy

Schedule conflict check

Write a function that takes a list of time intervals and returns True if any two overlap.

datetime intervals overlap

Datetime & Time Calculations easy

Month End Date

Implement a function that returns the last day of the month for a given year and month.

datetime calendar leap-year

Datetime & Time Calculations easy

Month Start Date

Parse a date string and return the first day of its month in the same format.

datetime date-parsing formatting

Datetime & Time Calculations easy

Daylight saving check

Given a date in the US, determine if daylight saving time starts or ends on that day.

datetime timezones dst

Datetime & Time Calculations easy

Time Slot Generator

Generate a list of time slots of a specified duration within a start and end time.

datetime time scheduling

Data Formats & Parsing easy

Update Row by ID

Given a list of CSV rows and target ID, replace the first matching row's value.

csv parsing list

SQL & SQLite easy

Cumulative Sum SQL

Write a SQL query to compute cumulative sales totals per product ordered by sale date.

sql window-functions running-total

Showing 25–33 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.