regex-buddy

Plain English to Regex - Your friendly regex helper.

Stop struggling with regex syntax. Just describe what you want to match in plain English.

Key Features:

• 24+ built-in patterns with explanations
• Debug why your regex doesn't match (the killer feature!)
• Plain English to regex conversion
• Quick reference cheatsheet with escape guide
• Interactive regex builder
• Auto-diagnose problems when testing fails

Installation

pip install regex-buddy

Quick Start

# Get a pattern by name
regex-buddy get email

# List all available patterns
regex-buddy list

# Test a pattern against text
regex-buddy test email -t "Contact us at hello@example.com"

# Find a pattern by description
regex-buddy find "match phone numbers"

# Interactive mode
regex-buddy interactive

Built-in Patterns

regex-buddy comes with 25+ pre-built patterns:

Usage Examples

Get a Pattern

$ regex-buddy get email

[email]
  Pattern: [a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}
  Description: Match email addresses

  Python: r"[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}"
  JavaScript: /[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}/g

Get with Explanation

$ regex-buddy get email -v

[email]
  Pattern: [a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}
  Description: Match email addresses

  Breakdown:
    [a-zA-Z0-9._%+-]+ - Username (letters, numbers, dots, underscores, etc.)
    @ - The @ symbol
    [a-zA-Z0-9.-]+ - Domain name
    \. - A literal dot
    [a-zA-Z]{2,} - Top-level domain (com, org, etc.)

  Examples that match:
    user@example.com
    test.email+tag@domain.co.uk

Test a Pattern

$ regex-buddy test email -t "Send to john@example.com or jane@test.org"

Matches found: 2

Matches:
  1. john@example.com
  2. jane@test.org

Find by Description

$ regex-buddy find "match urls"

Found built-in pattern: url
  Pattern: https?://(?:www\.)?...
  Description: Match URLs (http and https)

Debug Why It Doesn't Match (The Killer Feature!)

$ regex-buddy debug "www.google.com" "visit www.google.com today"

Debugging pattern: www.google.com
Against text: visit www.google.com today

Pattern DOES match: ['www.google.com']

Suggestions:
  - '.' in your pattern: Dot matches ANY character. Use \. for literal dot
  - Consider using \b for word boundaries to avoid partial matches

The debug command catches common issues:

• Unescaped special characters (dots, asterisks, etc.)
• Case sensitivity problems
• Anchor issues (^ and $)
• Greedy vs lazy matching
• Missing word boundaries
• Shows partial matches to help you find where it breaks

Cheatsheet

# Quick reference
$ regex-buddy cheatsheet

# Escape guide (what characters need escaping)
$ regex-buddy cheatsheet -e

Explain Any Pattern

$ regex-buddy explain "[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}"

Pattern: [a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}

Breakdown:
  [a-zA-Z0-9._%+-] - Any character in: a-zA-Z0-9._%+-
  + - One or more of previous
  [a-zA-Z] - Any character in: a-zA-Z
  {2,} - 2 or more times

Potential issues:
  - Unescaped '.' - matches ANY character. Did you mean '\.'?

Interactive Mode

$ regex-buddy interactive

regex-buddy interactive mode
Commands: list, get <name>, test <pattern>, explain <pattern>, find <description>, quit

regex> get phone
regex> test email
Enter text to test (empty line to finish):
my email is test@example.com
please reply to hello@world.org

Matches found: 2

Python API

from regex_buddy import (
    get_pattern, test_pattern, list_patterns,
    debug_no_match, check_common_mistakes, RegexBuilder
)

# Get a pattern
email_pattern = get_pattern("email")
print(email_pattern["pattern"])
# [a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}

# Test a pattern
result = test_pattern(email_pattern["pattern"], "Contact: user@example.com")
print(result["matches"])
# ['user@example.com']

# Debug why something doesn't match
diag = debug_no_match(r"www.google.com", "visit www.google.com")
print(diag["suggestions"])
# ['Dot matches ANY character. Use \\. for literal dot', ...]

# Check for common mistakes before they cause problems
warnings = check_common_mistakes(r"(a+)+")
# [{'type': 'catastrophic_backtracking', 'message': '...'}]

# Build patterns interactively
builder = RegexBuilder()
pattern = (builder
    .start()
    .digits(exact=3)
    .literal("-")
    .digits(exact=4)
    .end()
    .build())
print(pattern)  # ^\d{3}\-\d{4}$

# List all patterns
patterns = list_patterns()
for name, description in patterns.items():
    print(f"{name}: {description}")

Support

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• Buy Me a Coffee
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License

MIT License