gh-jtsylve-claude-experiments-meta-prompt/skills/data-extraction/SKILL.md

Data Extraction

Extract specific information from unstructured/semi-structured data with completeness and accuracy.

Common Patterns

Type	Pattern	Validation
Email	user@domain.ext	Has @ and . after @
URL	http(s)://domain...	Valid protocol and domain
Date	ISO, US, EU, timestamp	Valid ranges (month 1-12)
Phone	Various formats	7-15 digits
IP	IPv4: x.x.x.x, IPv6	Octets 0-255
Key-Value	key=value, key: value	Handle quoted/nested

Process

1. Analyze: Format, delimiters, variations, headers to skip
2. Extract: Match all instances, capture context, handle partial matches
3. Clean: Trim, normalize (dates to ISO, phones to digits), validate
4. Format: Consistent fields, proper escaping, sort/dedupe if needed

Output Formats

JSON: {"results": [...], "summary": {"total": N, "unique": N}}

CSV: Headers + rows

Markdown: Table with headers

Plain: Bullet list

Principles

• Complete: Extract ALL matches, don't stop early
• Accurate: Preserve exact values, maintain case
• Handle edge cases: Missing → null, malformed → flag, duplicates → note

Output Structure

[Extracted data]

## Summary
- Total: X
- Unique: Y
- Issues: Z

## Notes
- Line 42: Partial match "user@" (missing domain)