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pdf-extraction skill

/skills/lijie420461340/pdf-extraction

This skill extracts text, tables, and metadata from PDFs using pdfplumber, delivering structured data for analysis and downstream processing.

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SKILL.md
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---
name: pdf-extraction
description: Extract text, tables, and metadata from PDFs using pdfplumber
author: claude-office-skills
version: "1.0"
tags: [pdf, extraction, pdfplumber, tables, text]
models: [claude-sonnet-4, claude-opus-4]
tools: [computer, code_execution, file_operations]
library:
  name: pdfplumber
  url: https://github.com/jsvine/pdfplumber
  stars: 9.6k
---

# PDF Extraction Skill

## Overview

This skill enables precise extraction of text, tables, and metadata from PDF documents using **pdfplumber** - the go-to library for PDF data extraction. Unlike basic PDF readers, pdfplumber provides detailed character-level positioning, accurate table detection, and visual debugging.

## How to Use

1. Provide the PDF file you want to extract from
2. Specify what you need: text, tables, images, or metadata
3. I'll generate pdfplumber code and execute it

**Example prompts:**
- "Extract all tables from this financial report"
- "Get text from pages 5-10 of this document"
- "Find and extract the invoice total from this PDF"
- "Convert this PDF table to CSV/Excel"

## Domain Knowledge

### pdfplumber Fundamentals

```python
import pdfplumber

# Open PDF
with pdfplumber.open('document.pdf') as pdf:
    # Access pages
    first_page = pdf.pages[0]
    
    # Document metadata
    print(pdf.metadata)
    
    # Number of pages
    print(len(pdf.pages))
```

### PDF Structure
```
PDF Document
├── metadata (title, author, creation date)
├── pages[]
│   ├── chars (individual characters with position)
│   ├── words (grouped characters)
│   ├── lines (horizontal/vertical lines)
│   ├── rects (rectangles)
│   ├── curves (bezier curves)
│   └── images (embedded images)
└── outline (bookmarks/TOC)
```

### Text Extraction

#### Basic Text
```python
with pdfplumber.open('document.pdf') as pdf:
    # Single page
    text = pdf.pages[0].extract_text()
    
    # All pages
    full_text = ''
    for page in pdf.pages:
        full_text += page.extract_text() or ''
```

#### Advanced Text Options
```python
# With layout preservation
text = page.extract_text(
    x_tolerance=3,      # Horizontal tolerance for grouping
    y_tolerance=3,      # Vertical tolerance
    layout=True,        # Preserve layout
    x_density=7.25,     # Chars per unit width
    y_density=13        # Chars per unit height
)

# Extract words with positions
words = page.extract_words(
    x_tolerance=3,
    y_tolerance=3,
    keep_blank_chars=False,
    use_text_flow=False
)

# Each word includes: text, x0, top, x1, bottom, etc.
for word in words:
    print(f"{word['text']} at ({word['x0']}, {word['top']})")
```

#### Character-Level Access
```python
# Get all characters
chars = page.chars

for char in chars:
    print(f"'{char['text']}' at ({char['x0']}, {char['top']})")
    print(f"  Font: {char['fontname']}, Size: {char['size']}")
```

### Table Extraction

#### Basic Table Extraction
```python
with pdfplumber.open('report.pdf') as pdf:
    page = pdf.pages[0]
    
    # Extract all tables
    tables = page.extract_tables()
    
    for i, table in enumerate(tables):
        print(f"Table {i+1}:")
        for row in table:
            print(row)
```

#### Advanced Table Settings
```python
# Custom table detection
table_settings = {
    "vertical_strategy": "lines",      # or "text", "explicit"
    "horizontal_strategy": "lines",
    "explicit_vertical_lines": [],     # Custom line positions
    "explicit_horizontal_lines": [],
    "snap_tolerance": 3,
    "snap_x_tolerance": 3,
    "snap_y_tolerance": 3,
    "join_tolerance": 3,
    "edge_min_length": 3,
    "min_words_vertical": 3,
    "min_words_horizontal": 1,
    "intersection_tolerance": 3,
    "text_tolerance": 3,
    "text_x_tolerance": 3,
    "text_y_tolerance": 3,
}

tables = page.extract_tables(table_settings)
```

#### Table Finding
```python
# Find tables (without extracting)
table_finder = page.find_tables()

for table in table_finder:
    print(f"Table at: {table.bbox}")  # (x0, top, x1, bottom)
    
    # Extract specific table
    data = table.extract()
```

### Visual Debugging

```python
# Create visual debug image
im = page.to_image(resolution=150)

# Draw detected objects
im.draw_rects(page.chars)        # Character bounding boxes
im.draw_rects(page.words)        # Word bounding boxes
im.draw_lines(page.lines)        # Lines
im.draw_rects(page.rects)        # Rectangles

# Save debug image
im.save('debug.png')

# Debug tables
im.reset()
im.debug_tablefinder()
im.save('table_debug.png')
```

### Cropping and Filtering

#### Crop to Region
```python
# Define bounding box (x0, top, x1, bottom)
bbox = (0, 0, 300, 200)

# Crop page
cropped = page.crop(bbox)

# Extract from cropped area
text = cropped.extract_text()
tables = cropped.extract_tables()
```

#### Filter by Position
```python
# Filter characters by region
def within_bbox(obj, bbox):
    x0, top, x1, bottom = bbox
    return (obj['x0'] >= x0 and obj['x1'] <= x1 and
            obj['top'] >= top and obj['bottom'] <= bottom)

bbox = (100, 100, 400, 300)
filtered_chars = [c for c in page.chars if within_bbox(c, bbox)]
```

#### Filter by Font
```python
# Get text by font
def extract_by_font(page, font_name):
    chars = [c for c in page.chars if font_name in c['fontname']]
    return ''.join(c['text'] for c in chars)

# Extract bold text (often "Bold" in font name)
bold_text = extract_by_font(page, 'Bold')

# Extract by size
large_chars = [c for c in page.chars if c['size'] > 14]
```

### Metadata and Structure

```python
with pdfplumber.open('document.pdf') as pdf:
    # Document metadata
    meta = pdf.metadata
    print(f"Title: {meta.get('Title')}")
    print(f"Author: {meta.get('Author')}")
    print(f"Created: {meta.get('CreationDate')}")
    
    # Page info
    for i, page in enumerate(pdf.pages):
        print(f"Page {i+1}: {page.width} x {page.height}")
        print(f"  Rotation: {page.rotation}")
```

## Best Practices

1. **Debug Visually**: Use `to_image()` to understand PDF structure
2. **Tune Table Settings**: Adjust tolerances for your specific PDF
3. **Handle Scanned PDFs**: Use OCR first (this skill is for native text)
4. **Process Page by Page**: For large PDFs, avoid loading all at once
5. **Check for Text**: Some PDFs are images - verify text exists

## Common Patterns

### Extract All Tables to DataFrames
```python
import pandas as pd

def pdf_tables_to_dataframes(pdf_path):
    """Extract all tables from PDF as pandas DataFrames."""
    dfs = []
    
    with pdfplumber.open(pdf_path) as pdf:
        for i, page in enumerate(pdf.pages):
            tables = page.extract_tables()
            
            for j, table in enumerate(tables):
                if table and len(table) > 1:
                    # First row as header
                    df = pd.DataFrame(table[1:], columns=table[0])
                    df['_page'] = i + 1
                    df['_table'] = j + 1
                    dfs.append(df)
    
    return dfs
```

### Extract Specific Region
```python
def extract_invoice_amount(pdf_path):
    """Extract amount from typical invoice layout."""
    with pdfplumber.open(pdf_path) as pdf:
        page = pdf.pages[0]
        
        # Search for "Total" and get nearby numbers
        words = page.extract_words()
        
        for i, word in enumerate(words):
            if 'total' in word['text'].lower():
                # Look at next few words
                for next_word in words[i+1:i+5]:
                    text = next_word['text'].replace(',', '').replace('$', '')
                    try:
                        return float(text)
                    except ValueError:
                        continue
    
    return None
```

### Multi-column Layout
```python
def extract_columns(page, num_columns=2):
    """Extract text from multi-column layout."""
    width = page.width
    col_width = width / num_columns
    
    columns = []
    for i in range(num_columns):
        x0 = i * col_width
        x1 = (i + 1) * col_width
        
        cropped = page.crop((x0, 0, x1, page.height))
        columns.append(cropped.extract_text())
    
    return columns
```

## Examples

### Example 1: Financial Report Table Extraction
```python
import pdfplumber
import pandas as pd

def extract_financial_tables(pdf_path):
    """Extract tables from financial report and save to Excel."""
    
    with pdfplumber.open(pdf_path) as pdf:
        all_tables = []
        
        for page_num, page in enumerate(pdf.pages):
            # Debug: save table visualization
            im = page.to_image()
            im.debug_tablefinder()
            im.save(f'debug_page_{page_num+1}.png')
            
            # Extract tables
            tables = page.extract_tables({
                "vertical_strategy": "lines",
                "horizontal_strategy": "lines",
                "snap_tolerance": 5,
            })
            
            for table in tables:
                if table and len(table) > 1:
                    # Clean data
                    clean_table = []
                    for row in table:
                        clean_row = [cell.strip() if cell else '' for cell in row]
                        clean_table.append(clean_row)
                    
                    df = pd.DataFrame(clean_table[1:], columns=clean_table[0])
                    df['Source Page'] = page_num + 1
                    all_tables.append(df)
        
        # Save to Excel with multiple sheets
        with pd.ExcelWriter('extracted_tables.xlsx') as writer:
            for i, df in enumerate(all_tables):
                df.to_excel(writer, sheet_name=f'Table_{i+1}', index=False)
        
        return all_tables

tables = extract_financial_tables('annual_report.pdf')
print(f"Extracted {len(tables)} tables")
```

### Example 2: Invoice Data Extraction
```python
import pdfplumber
import re
from datetime import datetime

def extract_invoice_data(pdf_path):
    """Extract structured data from invoice PDF."""
    
    data = {
        'invoice_number': None,
        'date': None,
        'total': None,
        'line_items': []
    }
    
    with pdfplumber.open(pdf_path) as pdf:
        page = pdf.pages[0]
        text = page.extract_text()
        
        # Extract invoice number
        inv_match = re.search(r'Invoice\s*#?\s*:?\s*(\w+)', text, re.IGNORECASE)
        if inv_match:
            data['invoice_number'] = inv_match.group(1)
        
        # Extract date
        date_match = re.search(r'Date\s*:?\s*(\d{1,2}[/-]\d{1,2}[/-]\d{2,4})', text)
        if date_match:
            data['date'] = date_match.group(1)
        
        # Extract total
        total_match = re.search(r'Total\s*:?\s*\$?([\d,]+\.?\d*)', text, re.IGNORECASE)
        if total_match:
            data['total'] = float(total_match.group(1).replace(',', ''))
        
        # Extract line items from table
        tables = page.extract_tables()
        for table in tables:
            if table and any('description' in str(row).lower() for row in table[:2]):
                # Found line items table
                for row in table[1:]:  # Skip header
                    if row and len(row) >= 3:
                        data['line_items'].append({
                            'description': row[0],
                            'quantity': row[1] if len(row) > 1 else None,
                            'amount': row[-1]
                        })
    
    return data

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

### Example 3: Resume/CV Parser
```python
import pdfplumber

def parse_resume(pdf_path):
    """Extract structured sections from resume."""
    
    with pdfplumber.open(pdf_path) as pdf:
        full_text = ''
        for page in pdf.pages:
            full_text += (page.extract_text() or '') + '\n'
        
        # Common resume sections
        sections = {
            'contact': '',
            'summary': '',
            'experience': '',
            'education': '',
            'skills': ''
        }
        
        # Split by common headers
        import re
        section_patterns = {
            'summary': r'(summary|objective|profile)',
            'experience': r'(experience|employment|work history)',
            'education': r'(education|academic)',
            'skills': r'(skills|competencies|technical)'
        }
        
        lines = full_text.split('\n')
        current_section = 'contact'
        
        for line in lines:
            line_lower = line.lower().strip()
            
            # Check if line is a section header
            for section, pattern in section_patterns.items():
                if re.match(pattern, line_lower):
                    current_section = section
                    break
            
            sections[current_section] += line + '\n'
        
        return sections

resume = parse_resume('resume.pdf')
print("Skills:", resume['skills'])
```

## Limitations

- Cannot extract from scanned/image PDFs (use OCR first)
- Complex layouts may need manual tuning
- Some PDF encryption types not supported
- Embedded fonts may affect text extraction
- No direct PDF editing capability

## Installation

```bash
pip install pdfplumber

# For image debugging (optional)
pip install Pillow
```

## Resources

- [pdfplumber Documentation](https://github.com/jsvine/pdfplumber)
- [Table Extraction Guide](https://github.com/jsvine/pdfplumber#extracting-tables)
- [Visual Debugging](https://github.com/jsvine/pdfplumber#visual-debugging)

Overview

This skill extracts text, tables, and metadata from PDF documents using pdfplumber. It focuses on precise, position-aware extraction and provides tools for table detection, region cropping, and visual debugging to speed up data extraction workflows.

How this skill works

You provide a PDF and specify the target (text, tables, images, or metadata). The skill uses pdfplumber to open the file, inspect page-level objects (chars, words, lines, rects, images), and run extraction routines. It can crop regions, filter by position or font, detect and extract tables with custom settings, and render debug images to visualize detections.

When to use it

  • Extract structured tables from reports or invoices to convert into CSV/Excel.
  • Pull specific text blocks or metadata (title, author, creation date) from native PDFs.
  • Crop or filter pages to capture data from a known region (e.g., invoice totals).
  • Debug extraction issues by visualizing characters, lines, and table boundaries.
  • Process multi-column documents or resumes to separate content by column.

Best practices

  • Visualize with to_image() and debug_tablefinder() to tune extraction settings before batch runs.
  • Process large PDFs page-by-page to reduce memory usage and improve reliability.
  • Tune table detection tolerances (snap, join, intersection) per document family.
  • Verify the PDF contains selectable text; run OCR beforehand for scanned images.
  • Use character- and font-level filters when extracting specific styles like bold or large headings.

Example use cases

  • Extract all financial tables from an annual report and save each table to separate Excel sheets.
  • Locate an invoice total by searching for 'Total' and parsing nearby numeric tokens.
  • Parse resumes into structured sections (contact, experience, education, skills) for HR ingestion.
  • Crop a page region to extract a multi-column article and combine column text sequentially.
  • Generate debug images showing detected tables and character boxes to refine table settings.

FAQ

Can this handle scanned PDFs?

Not directly. Run OCR first to convert images into selectable text, then use this skill on the OCRed PDF.

How accurate is table extraction?

Accuracy depends on table borders and layout. Using visual debugging and tuning table_settings (strategies and tolerances) improves results significantly.