Python Challenge - Solutions

Spoiler Alert! This page contains solutions. Try the puzzles first at pythonchallenge.com.

The Python Challenge is a classic puzzle game where each level requires you to write a small program to reveal the URL of the next level. It's a fantastic way to learn Python's standard library — string manipulation, HTTP, regex, binary formats, image processing.

What's different about these solutions

Each solution page includes:

• Python — the idiomatic solution using stdlib
• Go — solution using the Go standard library where possible
• Rust — solution using common crates (reqwest, regex, serde-pickle)
• Language Comparison — a table highlighting what each puzzle teaches about how Python, Go, and Rust differ

Levels

Level	Puzzle	Key Concept
Level 1	Caesar cipher on the URL	str.maketrans vs character mapping
Level 2	Find rare characters in noise	Counter vs HashMap
Level 3	Regex with exact boundary count	Lookbehind: PCRE vs RE2
Level 4	Follow HTTP linked list	urllib vs net/http vs reqwest
Level 5	Decode a pickled banner	pickle portability & security
Level 6	Traverse a ZIP comment chain	ZIP file handling
Level 7	Decode grayscale pixel data	Image processing with Pillow
Level 8	Inflate bzip2 credentials	zlib / bz2 decompression
Level 9	Connect coordinate point pairs	Polygon drawing with Pillow
Level 10	Longest run of a character	itertools.groupby
Level 11	Odd/even pixel checkerboard	Image pixel manipulation
Level 12	Eval a dirty string	eval()
Level 13	XMLRPC remote call	xmlrpc.client
Level 14	Reconstruct image from stripes	Image reassembly
Level 15	Year/month calendar puzzle	calendar module
Level 16	Shift image rows	Pixel-level manipulation
Level 17	Find pairs in two lists	Set intersection
Level 18	Follow cookie chain	HTTP cookies
Level 19	Reverse audio to find message	wave module
Level 20	Base64 + URL chain	base64 + urllib
Level 21	Decompress layered archive	zlib + bz2
Level 22	Draw lines from coordinates	ImageDraw
Level 23	The Zen of Python	import this
Level 24	Solve a pixel maze	BFS on image pixels
Level 25	Decode a WAV file	wave + audio bytes
Level 26	Email the answer	SMTP
Level 27	Extract palette from GIF	Image palette
Level 28	Pronounce RING-RING	wordplay
Level 29	Decode line-length bytes	HTML source parsing
Level 30	Parse CSV data	csv module
Level 31	Image click chain	Multi-step HTTP
Level 32	Simulate a clock	time + pixel drawing
Level 33	Convolve grayscale image	Image convolution