Python Coding Challenges

parsing strings dictionaries

Parse key=value pairs

Implement a parser that converts a space-separated 'key=value' string into a Python dictionary, supporting quoted values.

Find all numbers in text

Write a function that extracts all standalone integers from a text string using regular expressions.

regex parsing numbers

strings parsing file-paths

Extract file extensions

Implement a function that extracts the extension from a filename according to standard rules.

strings validation returns

Validate username format

Implement a function that validates a username according to length, allowed characters, and no consecutive underscores.

string-manipulation parsing template

Replace template variables

Implement a function that replaces {{variable}} placeholders in a string using a dictionary, leaving unknown placeholders intact.

strings character-comparison distance

Hamming Distance

Implement a function that computes the Hamming distance between two strings of equal length.

Hex encode decode

Write hex_encode and hex_decode to convert between hex strings and integer byte values.

hex encoding strings

strings cipher transformation

ROT13 Transform

Implement ROT13, a letter substitution cipher that rotates the alphabet by 13 positions.

Caesar Cipher Decrypt

Implement a function that decrypts a Caesar cipher by shifting letters back by a given number.

strings ascii cipher

strings deduplication order-preserving

Remove Duplicate Letters

Implement a function that removes duplicate characters from a string while preserving the order of their first occurrence.

url-parsing strings parsing

Parse URL components

Write parse_url that splits a URL into its standard components with defaults for missing parts.

Parse HTTP Status Line

Write a function that parses a well-formed HTTP status line into its three components.

strings parsing http

+8 pts 15m

Parse markdown headers

Write a function that parses markdown headers and returns their levels and texts.

markdown parsing strings

Parse bullet list

Parse a markdown-style bullet list and return the list of item texts, stripping bullet markers and trimming surrounding whitespace.

parsing strings markdown

string parsing strip split

Parse numbered list

Take a string containing a numbered list and return a clean list of the item texts.

Decode base64 string

Write a function that decodes a base64 string to its original UTF-8 text without using the base64 module.

base64 decode strings

Parse Version SemVer

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

strings parsing semver

strings parsing comparison

Compare Version Strings

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

Parse path segments

Implement a function that parses a path string into clean segments, ignoring slashes, empty parts, and dot segments.

strings parsing split

+10 pts 10m

Parse coordinate pairs

Parse a string of coordinate pairs into a list of coordinate lists.

parsing strings split

Parse range notation

Parse a comma-separated list of ranges and individual numbers, expanding each range into its full sequence.

strings parsing ranges

Parse Boolean Strings

Implement a function that parses a boolean string into a Python bool, handling True/False/Yes/No/1/0 case-insensitively.

strings boolean parsing

+10 pts 10m

strings formatting cleaning

User Friendly Message

Given a raw user input, format it into a single clean sentence with proper sentence case and trimming.

string parsing word-count

Find repeated words

Return a lowercase list of unique words that appear more than once across a given text, ignoring case.