Practice Arena

Python Coding Challenges

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

875 challenges 536 easy 303 medium 36 hard
Python Basics easy

Grade from Score

Write a function that maps a numeric score to its letter grade using standard grading thresholds.

conditionals functions integers
+8 pts 10m
Python Basics easy

Grade Calculator

Implement a function that converts a numeric score to a letter grade using a standard scale.

conditionals functions basic-syntax
+8 pts 10m
Python Basics easy

Variadic Sum Function

Implement a variadic function that sums an arbitrary number of numeric arguments.

functions args sum
+10 pts 10m
Python Basics easy

Cosine Similarity of Vectors

Compute the cosine similarity between two equal-length numeric vectors using pure Python.

math linear-algebra similarity
+10 pts 15m
Python Basics easy

Min-Max Scaler: Fit and Transform

Implement a MinMaxScaler class that normalizes numeric data to a given range using fit and transform methods.

scaling normalization class
+8 pts 12m
Strings & Text easy

Palindrome check

Return True if the string reads the same forwards and backwards (ignoring case and non-alphanumeric).

strings two-pointer
+8 pts 8m
Strings & Text easy

Parse Version SemVer

Write a function that parses a semantic version string into its numeric components.

strings parsing semver
+10 pts 15m
Strings & Text easy

Compare Version Strings

Given two version strings, compare them numerically by splitting on dots and ignoring leading zeros.

strings parsing comparison
+10 pts 15m
Dicts & Sets easy

Missing keys default zero

Write a function to sum numeric values from dictionaries, treating missing keys as zero.

dictionaries sum defaults
+10 pts 12m
Math & Number Theory easy

Dot Product of Vectors

Implement a function that returns the dot product of two numeric vectors.

math lists dot-product
+10 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.