Practice Arena

Python Coding Challenges

Write real Python in the browser. Instant feedback. From beginner to expert.

819 challenges 506 easy 280 medium 33 hard
Python Basics easy

Count trailing zeros

Write a function that counts the number of trailing zeros in the decimal representation of a positive integer.

loops integers basics
+5 pts 5m
Strings & Text easy

Strip Leading Zeros

Write a function that strips leading zeros from a string representing a non-negative integer.

strings strip lstrip
+5 pts 5m
OOP & Classes easy

Deck of Cards Class

Implement a Deck class representing a standard 52-card deck with shuffle, deal, and len support.

oop classes random
+10 pts 15m
OOP & Classes easy

String Representation Mixin

Implement a mixin class that provides generic __repr__ and __str__ based on instance attributes.

oop repr mixin
+10 pts 15m
OOP & Classes easy

Dataclass with slots

Implement a slotted frozen dataclass representing a 2D point with total ordering.

dataclass slots immutability
+10 pts 15m
Bit Manipulation easy

Count Set Bits

Implement a function that returns the number of set bits (1s) in the binary representation of a non-negative integer.

bit-manipulation binary counting
+10 pts 15m
Bit Manipulation easy

Gray Code Encode

Implement a function that converts a non-negative integer to its Gray code representation using bitwise XOR and shift.

bitwise gray-code encoding
+10 pts 15m
Bit Manipulation easy

Compress Bits Run

Write a function that compresses a binary string by representing consecutive identical bits as a count-bit pair.

bit-manipulation strings compression
+10 pts 15m
Bit Manipulation easy

Sparse Number Check

Check if a non-negative integer is sparse, meaning its binary representation contains no adjacent 1 bits.

bitwise binary conditionals
+10 pts 15m
Bit Manipulation easy

Odd Parity Bit

Given an integer, return the odd parity bit (0 or 1) so that total number of 1-bits in the 8-bit representation becomes odd.

bitwise parity integer
+8 pts 10m

Showing 10 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

  1. Pick a category — basics, algorithms, strings, and more
  2. Open a challenge, read the statement, and edit the starter code
  3. 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.