Regular Expressions and Text Processing

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Regular Expressions and Text Processing

Regular expressions are a powerful tool for text processing. This guide covers everything about regex -- from basic syntax, lookahead/​lookbehind, and named captures to Unicode support and implementations across different languages.

Target Audience

• Engineers who want to systematically learn regular expressions
• Developers looking to streamline text processing and data cleansing
• Those who want to improve their validation implementations

Prerequisites

• Basic programming experience
• Foundational knowledge of string manipulation

Study Guide

00-basics -- Regex Basics

01-advanced -- Advanced Features

02-languages -- Language-Specific Implementations

Quick Reference

Regex Cheat Sheet:
  .       -- Any single character
  \d \w \s -- Digit / word character / whitespace
  [abc]   -- Character class
  ^  $    -- Start / end of line
  *  +  ? -- 0 or more / 1 or more / 0 or 1
  {n,m}   -- Between n and m times
  (...)   -- Capture group
  (?:...) -- Non-capturing group
  (?=...) -- Lookahead
  (?<=..) -- Lookbehind
  \1      -- Backreference

References

1. Friedl, J. "Mastering Regular Expressions." O'Reilly, 2006.
2. regular-expressions.info -- Comprehensive reference
3. regex101.com -- Online tester