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
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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
Greedy Algorithms easy

Maximum Ice Cream Bars

Given costs of ice cream bars and coins, return the maximum number you can buy.

greedy sorting array
+10 pts 15m
Two Pointers & Sliding Window easy

Reduce array to zero

Given an array of non-negative integers, each operation chooses two indices and subtracts 1 from each if both are positive. Return the minimum number of operations to reduce the array to all zeros, or -1 if impossible.

two-pointers arrays greedy
+10 pts 15m
Datetime & Time Calculations easy

Days in month

Write a function that returns the number of days in a given month and year, correctly handling leap years.

datetime calendar leap-year
+8 pts 10m
Datetime & Time Calculations easy

Days Between Dates

Write a function that returns the number of days between two given dates.

datetime date-arithmetic calendar
+10 pts 15m
Datetime & Time Calculations easy

Add Days to Date

Given a date in YYYY-MM-DD format and an integer number of days, return the resulting date in the same format.

datetime date arithmetic
+8 pts 10m
Datetime & Time Calculations easy

Business days between

Calculate the number of business days (Mon-Fri) between two dates, inclusive of both endpoints.

datetime weekdays date-arithmetic
+10 pts 15m
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
+8 pts 12m
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
+10 pts 15m

Showing 97–104 of 104 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.