Python Coding Challenges

Validate time format

Check whether a given string is a valid 24-hour time in HH:MM format.

strings validation time

strings whitespace normalization

Replace multiple spaces

Implement a function that replaces every sequence of spaces with a single space.

Extract Quoted Strings

Write a function that extracts the text inside every double-quoted substring from a given string.

strings parsing quotes

strings parsing camelcase

Split on camelCase

Given a camelCase string, split it into words at uppercase letters and return them as lowercase words.

Extract domain from URL

Extract the domain (hostname without port or www) from a given URL string.

url parsing strings

strings whitespace split-join

Normalize Whitespace

Write a function that normalizes any whitespace in a string to single spaces and trims the ends.

+5 pts 10m

Strip Leading Zeros

Write a function that strips leading zeros from a string representing a non-negative integer.

strings strip lstrip

+5 pts 5m

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.

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.

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

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