Data Extractor Skill

Overview

This skill enables extraction of structured data from any document format using unstructured - a unified library for processing PDFs, Word docs, emails, HTML, and more. Get consistent, structured output regardless of input format.

How to Use

1. Provide the document to process
2. Optionally specify extraction options
3. I'll extract structured elements with metadata

Example prompts:

• "Extract all text and tables from this PDF"
• "Parse this email and get the body, attachments, and metadata"
• "Convert this HTML page to structured elements"
• "Extract data from these mixed-format documents"

Domain Knowledge

unstructured Fundamentals

from unstructured.partition.auto import partition

# Automatically detect and process any document
elements = partition("document.pdf")

# Access extracted elements
for element in elements:
    print(f"Type: {type(element).__name__}")
    print(f"Text: {element.text}")
    print(f"Metadata: {element.metadata}")

Supported Formats

Element Types

from unstructured.documents.elements import (
    Title,
    NarrativeText,
    Text,
    ListItem,
    Table,
    Image,
    Header,
    Footer,
    PageBreak,
    Address,
    EmailAddress,
)

# Elements have consistent structure
element.text           # Raw text content
element.metadata       # Rich metadata
element.category       # Element type
element.id            # Unique identifier

Auto Partition

from unstructured.partition.auto import partition

# Process any file type
elements = partition(
    filename="document.pdf",
    strategy="auto",          # or "fast", "hi_res", "ocr_only"
    include_metadata=True,
    include_page_breaks=True,
)

# Filter by type
titles = [e for e in elements if isinstance(e, Title)]
tables = [e for e in elements if isinstance(e, Table)]

Format-Specific Partitioning

# PDF with options
from unstructured.partition.pdf import partition_pdf

elements = partition_pdf(
    filename="document.pdf",
    strategy="hi_res",              # High quality extraction
    infer_table_structure=True,     # Detect tables
    include_page_breaks=True,
    languages=["en"],               # OCR language
)

# Word documents
from unstructured.partition.docx import partition_docx

elements = partition_docx(
    filename="document.docx",
    include_metadata=True,
)

# HTML
from unstructured.partition.html import partition_html

elements = partition_html(
    filename="page.html",
    include_metadata=True,
)

Working with Tables

from unstructured.partition.auto import partition

elements = partition("report.pdf", infer_table_structure=True)

# Extract tables
for element in elements:
    if element.category == "Table":
        print("Table found:")
        print(element.text)
        
        # Access structured table data
        if hasattr(element, 'metadata') and element.metadata.text_as_html:
            print("HTML:", element.metadata.text_as_html)

Metadata Access

from unstructured.partition.auto import partition

elements = partition("document.pdf")

for element in elements:
    meta = element.metadata
    
    # Common metadata fields
    print(f"Page: {meta.page_number}")
    print(f"Filename: {meta.filename}")
    print(f"Filetype: {meta.filetype}")
    print(f"Coordinates: {meta.coordinates}")
    print(f"Languages: {meta.languages}")

Chunking for AI/RAG

from unstructured.partition.auto import partition
from unstructured.chunking.title import chunk_by_title
from unstructured.chunking.basic import chunk_elements

# Partition document
elements = partition("document.pdf")

# Chunk by title (semantic chunks)
chunks = chunk_by_title(
    elements,
    max_characters=1000,
    combine_text_under_n_chars=200,
)

# Or basic chunking
chunks = chunk_elements(
    elements,
    max_characters=500,
    overlap=50,
)

for chunk in chunks:
    print(f"Chunk ({len(chunk.text)} chars):")
    print(chunk.text[:100] + "...")

Batch Processing

from unstructured.partition.auto import partition
from pathlib import Path
from concurrent.futures import ThreadPoolExecutor

def process_document(file_path):
    """Process single document."""
    try:
        elements = partition(str(file_path))
        return {
            'file': str(file_path),
            'status': 'success',
            'elements': len(elements),
            'text': '\n\n'.join([e.text for e in elements])
        }
    except Exception as e:
        return {
            'file': str(file_path),
            'status': 'error',
            'error': str(e)
        }

def batch_process(input_dir, max_workers=4):
    """Process all documents in directory."""
    input_path = Path(input_dir)
    files = list(input_path.glob('*'))
    
    with ThreadPoolExecutor(max_workers=max_workers) as executor:
        results = list(executor.map(process_document, files))
    
    return results

Export Formats

from unstructured.partition.auto import partition
from unstructured.staging.base import elements_to_json, elements_to_dicts

elements = partition("document.pdf")

# To JSON string
json_str = elements_to_json(elements)

# To list of dicts
dicts = elements_to_dicts(elements)

# To DataFrame
import pandas as pd
df = pd.DataFrame(dicts)

Best Practices

1. Choose Strategy Wisely: "fast" for speed, "hi_res" for accuracy
2. Enable Table Detection: For documents with tables
3. Specify Language: For better OCR on non-English docs
4. Chunk for RAG: Use semantic chunking for AI applications
5. Handle Errors: Some formats may fail gracefully

Common Patterns

Document to JSON

def document_to_json(file_path, output_path=None):
    """Convert document to structured JSON."""
    from unstructured.partition.auto import partition
    from unstructured.staging.base import elements_to_json
    import json
    
    elements = partition(file_path)
    
    # Create structured output
    output = {
        'source': file_path,
        'elements': []
    }
    
    for element in elements:
        output['elements'].append({
            'type': type(element).__name__,
            'text': element.text,
            'metadata': {
                'page': element.metadata.page_number,
                'coordinates': element.metadata.coordinates.to_dict() if element.metadata.coordinates else None
            }
        })
    
    if output_path:
        with open(output_path, 'w') as f:
            json.dump(output, f, indent=2)
    
    return output

Email Parser

from unstructured.partition.email import partition_email

def parse_email(email_path):
    """Extract structured data from email."""
    
    elements = partition_email(email_path)
    
    email_data = {
        'subject': None,
        'from': None,
        'to': [],
        'date': None,
        'body': [],
        'attachments': []
    }
    
    for element in elements:
        meta = element.metadata
        
        # Extract headers from metadata
        if meta.subject:
            email_data['subject'] = meta.subject
        if meta.sent_from:
            email_data['from'] = meta.sent_from
        if meta.sent_to:
            email_data['to'] = meta.sent_to
        
        # Body content
        email_data['body'].append({
            'type': type(element).__name__,
            'text': element.text
        })
    
    return email_data

Examples

Example 1: Research Paper Extraction

from unstructured.partition.pdf import partition_pdf
from unstructured.chunking.title import chunk_by_title

def extract_paper(pdf_path):
    """Extract structured data from research paper."""
    
    elements = partition_pdf(
        filename=pdf_path,
        strategy="hi_res",
        infer_table_structure=True,
        include_page_breaks=True
    )
    
    paper = {
        'title': None,
        'abstract': None,
        'sections': [],
        'tables': [],
        'references': []
    }
    
    # Find title (usually first Title element)
    for element in elements:
        if element.category == "Title" and not paper['title']:
            paper['title'] = element.text
            break
    
    # Extract tables
    for element in elements:
        if element.category == "Table":
            paper['tables'].append({
                'page': element.metadata.page_number,
                'content': element.text,
                'html': element.metadata.text_as_html if hasattr(element.metadata, 'text_as_html') else None
            })
    
    # Chunk into sections
    chunks = chunk_by_title(elements, max_characters=2000)
    
    current_section = None
    for chunk in chunks:
        if chunk.category == "Title":
            paper['sections'].append({
                'title': chunk.text,
                'content': ''
            })
        elif paper['sections']:
            paper['sections'][-1]['content'] += chunk.text + '\n'
    
    return paper

paper = extract_paper('research_paper.pdf')
print(f"Title: {paper['title']}")
print(f"Tables: {len(paper['tables'])}")
print(f"Sections: {len(paper['sections'])}")

Example 2: Invoice Data Extraction

from unstructured.partition.auto import partition
import re

def extract_invoice_data(file_path):
    """Extract key data from invoice."""
    
    elements = partition(file_path, strategy="hi_res")
    
    # Combine all text
    full_text = '\n'.join([e.text for e in elements])
    
    invoice = {
        'invoice_number': None,
        'date': None,
        'total': None,
        'vendor': None,
        'line_items': [],
        'tables': []
    }
    
    # Extract patterns
    inv_match = re.search(r'Invoice\s*#?\s*:?\s*(\w+[-\w]*)', full_text, re.I)
    if inv_match:
        invoice['invoice_number'] = inv_match.group(1)
    
    date_match = re.search(r'Date\s*:?\s*(\d{1,2}[-/]\d{1,2}[-/]\d{2,4})', full_text, re.I)
    if date_match:
        invoice['date'] = date_match.group(1)
    
    total_match = re.search(r'Total\s*:?\s*\$?([\d,]+\.?\d*)', full_text, re.I)
    if total_match:
        invoice['total'] = float(total_match.group(1).replace(',', ''))
    
    # Extract tables
    for element in elements:
        if element.category == "Table":
            invoice['tables'].append(element.text)
    
    return invoice

invoice = extract_invoice_data('invoice.pdf')
print(f"Invoice #: {invoice['invoice_number']}")
print(f"Total: ${invoice['total']}")

Example 3: Document Corpus Builder

from unstructured.partition.auto import partition
from unstructured.chunking.title import chunk_by_title
from pathlib import Path
import json

def build_corpus(input_dir, output_path):
    """Build searchable corpus from document collection."""
    
    input_path = Path(input_dir)
    corpus = []
    
    # Support multiple formats
    patterns = ['*.pdf', '*.docx', '*.html', '*.txt', '*.md']
    files = []
    for pattern in patterns:
        files.extend(input_path.glob(pattern))
    
    for file in files:
        print(f"Processing: {file.name}")
        
        try:
            elements = partition(str(file))
            chunks = chunk_by_title(elements, max_characters=1000)
            
            for i, chunk in enumerate(chunks):
                corpus.append({
                    'id': f"{file.stem}_{i}",
                    'source': str(file),
                    'type': type(chunk).__name__,
                    'text': chunk.text,
                    'page': chunk.metadata.page_number if chunk.metadata.page_number else None
                })
        
        except Exception as e:
            print(f"  Error: {e}")
    
    # Save corpus
    with open(output_path, 'w') as f:
        json.dump(corpus, f, indent=2)
    
    print(f"Corpus built: {len(corpus)} chunks from {len(files)} files")
    return corpus

corpus = build_corpus('./documents', 'corpus.json')

Limitations

• Complex layouts may need manual review
• OCR quality depends on image quality
• Large files may need chunking
• Some proprietary formats not supported
• API rate limits for cloud processing

Installation

# Basic installation
pip install unstructured

# With all dependencies
pip install "unstructured[all-docs]"

# For PDF processing
pip install "unstructured[pdf]"

# For specific formats
pip install "unstructured[docx,pptx,xlsx]"

Resources

• unstructured GitHub
• Documentation
• Unstructured API