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Python Coding
Challenges

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925 challenges 556 easy 323 medium 46 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

Math & Number Theory easy

Abundant Number Check

Implement a function to check whether a given integer is abundant: sum of proper divisors exceeds the number.

math divisors number-theory

Math & Number Theory easy

Amicable Numbers Check

Write a function that checks if two numbers are an amicable pair by comparing sums of proper divisors.

divisors arithmetic math

Math & Number Theory easy

Deficient Number Check

Write is_deficient(n) that returns True if the sum of proper divisors is less than n.

math number-theory divisors

Bit Manipulation easy

Isolate Rightmost Set Bit

Given an integer, return a number with only its rightmost set bit set.

bit-manipulation bitwise algorithms

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

Week Number ISO

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

datetime iso date

Cryptography & Hashing easy

Constant Time Compare

Write a function that compares two strings without leaking length or content via timing.

constant-time security comparison

Showing 25–31 of 31 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.