Python Coding Challenges

strings case-conversion parsing

Kebab Case Converter

Implement a function that converts any string to kebab-case, handling spaces, underscores, camelCase, and punctuation.

+8 pts 15m

strings case-insensitive set

Is isogram?

Write a function that checks whether a given word is an isogram, ignoring letter case and only considering alphabetic characters.

Rotate String Right

Implement a function that rotates a given string to the right by a specified number of positions, handling shifts larger than the string length.

strings rotation slicing

string run-length compression

Compress Consecutive Chars

Write a function that compresses a string by replacing runs of identical characters with the character followed by the count.

strings parsing run-length-encoding

Expand compressed string

Implement a function that expands run-length encoded strings (e.g., 'a3b2' → 'aaabb').

Find substring index

Implement a function that returns the starting index of the first occurrence of a substring using only basic string indexing and slicing.

string search index

strings counting substrings

Count Substrings

Implement a function that counts non-overlapping occurrences of a substring in a given string.

Sort characters in string

Write a function that sorts the characters in a string and returns the sorted string.

sorting string character

Index of First Occurrence

Implement a function that finds the starting index of a substring within a string, returning -1 when absent.

strings search index

formatting strings function

Error message formatter

Write a function that constructs a formatted error message from a code, an optional context, and a fallback message.

Stack Trace Sanitizer

Implement a function that rewrites traceback file paths to basenames only.

strings regex parsing

string-parsing split strip

Parse Log Line

Write a function that parses a log line and returns a dictionary with timestamp, level, and message.

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 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

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.

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.