Practice Arena

Python Coding Challenges

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

467 challenges 330 easy 120 medium 17 hard
Iterators & Generators easy

Custom iterator class

Implement a custom iterator class that repeatedly yields elements from a list up to a given number of times.

iterator class cycle
+10 pts 15m
Iterators & Generators easy

Generator Pipeline

Implement a generator function that yields only even numbers from an input list, squared.

generators lazy-evaluation filter
+8 pts 12m
Iterators & Generators easy

Range-like generator

Implement a custom generator that yields numbers like Python's range but with flexible bounds.

generator yield range
+8 pts 12m
Iterators & Generators easy

Fibonacci Generator

Create a generator function that yields Fibonacci numbers from 0 upward until a given limit.

generator fibonacci lazy evaluation
+8 pts 10m
Iterators & Generators easy

Window Iterator

Implement a generator that yields consecutive windows of a given size from any iterable.

generators yield sliding-window
+8 pts 12m
Iterators & Generators easy

Pairwise Sequence Pairs

Write a generator function pairwise that yields each consecutive overlapping pair from any iterable as lists.

generators iterators pairs
+10 pts 15m
Iterators & Generators easy

Groupby Consecutive

Write a generator function that yields (value, list_of_occurrences) for each run of consecutive equal items.

generator groupby consecutive
+8 pts 12m
Iterators & Generators easy

Collatz Generator

Implement a generator function that yields the Collatz sequence starting from a given positive integer.

generators collatz sequence
+10 pts 10m
Iterators & Generators easy

Digit Expansion Generator

Create a generator that lazily yields each decimal digit of a non-negative integer from most significant to least significant.

generators yield digits
+8 pts 10m
Iterators & Generators easy

File Line Reader Generator

Implement a generator function that reads a file-like object and yields each non-empty line without loading the whole file into memory.

generators file-io lazy-evaluation
+10 pts 15m
Iterators & Generators easy

Tree inorder generator

Write a generator function that yields a binary tree's node values in inorder traversal.

generator inorder binary-tree
+10 pts 15m
Iterators & Generators easy

Yield from delegation

Implement a generator that flattens nested iterables of any depth using `yield from`.

generators yield delegation
+8 pts 10m

Showing 12 challenges · easy · Iterators & Generators

Iterators & Generators — Python coding challenges

What you will find here

This page lists iterators & generators 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.