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Python Coding
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467 challenges 330 easy 120 medium 17 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

Strings & Text easy

Is pangram

Write a function that determines whether a given string is a pangram, ignoring case and non-letter characters.

strings sets algorithm

Strings & Text easy

Find substring index

Implement a function that returns the starting index of the first occurrence of a substring using only basic string indexing and slicing.

string search index

Lists & Arrays easy

Counting Sort

Implement the counting sort algorithm to sort a list of non-negative integers in O(n + k) time.

sorting counting arrays

Data Structures & Algorithms easy

Bubble Sort

Implement bubble sort that sorts a list of numbers in ascending order.

sorting arrays algorithms

Data Structures & Algorithms easy

Selection Sort Implementation

Implement selection sort to sort a list of numbers in ascending order.

sorting selection-sort algorithm

Data Structures & Algorithms easy

Shell Sort

Implement Shell sort, an in-place comparison sort that generalizes insertion sort, using a gap sequence that shrinks by half each pass.

sorting shell-sort in-place

Data Structures & Algorithms easy

Exponential Search

Implement exponential search to find any valid index of a target in a sorted list.

searching sorted-array algorithms

Bit Manipulation easy

Isolate Rightmost Set Bit

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

bit-manipulation bitwise algorithms

Bit Manipulation easy

Brian Kernighan count

Implement a function that counts set bits using Brian Kernighan's efficient algorithm.

bit-manipulation integers counting

Showing 9 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.