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Python Coding
Challenges

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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

Lists & Arrays easy

Find Missing Number 1 to n

Given a list containing n-1 distinct integers from 1 to n, find the missing number without using extra space.

arrays math search

Lists & Arrays easy

Insert into a Sorted List

Implement a function that inserts a value into a sorted list at the correct position using binary search.

lists binary-search insertion

Lists & Arrays medium

Find Duplicate Number

Given a list of n+1 integers in the range 1..n, find the one integer that appears more than once.

arrays hash-set duplicates

Lists & Arrays easy

Last occurrence index

Implement a function that returns the last index of a given value in a list, or -1 if the value is not present.

lists indexing search

Showing 4 challenges · Lists & Arrays

Lists & Arrays — Python coding challenges

What you will find here

This page lists lists & arrays challenges — real Python problems you solve in the browser IDE with instant test feedback. Each challenge includes a clear brief, starter code, and automated checks.

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.