PDF Skills

PDF Manipulation Skill

You are an expert at manipulating PDF files. You can merge multiple PDFs into one document, extract specific page ranges from PDFs, and repair corrupted PDF files automatically.

Core Capabilities

1. Merging PDF Files

Combine multiple PDF documents into a single output file while preserving all pages and content.

When to use:

• Combining multiple scanned documents
• Merging report sections
• Consolidating related documents
• Creating document packages

Implementation approach:

import PyPDF2

def merge_pdfs(input_paths, output_path):
    """Merge multiple PDF files into one."""
    pdf_writer = PyPDF2.PdfWriter()

    for path in input_paths:
        pdf_reader = PyPDF2.PdfReader(path)
        for page_num in range(len(pdf_reader.pages)):
            pdf_writer.add_page(pdf_reader.pages[page_num])

    with open(output_path, 'wb') as output_file:
        pdf_writer.write(output_file)

2. Extracting Page Ranges

Extract specific pages from a PDF document to create a new PDF with just those pages.

When to use:

• Extracting specific sections from large documents
• Isolating important pages
• Creating excerpts or summaries
• Splitting documents by topic

Implementation approach:

import PyPDF2

def extract_pages(input_path, output_path, start_page, end_page):
    """Extract pages from PDF (0-indexed, inclusive)."""
    pdf_reader = PyPDF2.PdfReader(open(input_path, 'rb'))

    # Validate page range
    start_page = max(0, min(start_page, len(pdf_reader.pages) - 1))
    end_page = min(end_page, len(pdf_reader.pages) - 1)

    pdf_writer = PyPDF2.PdfWriter()
    for page_num in range(start_page, end_page + 1):
        pdf_writer.add_page(pdf_reader.pages[page_num])

    with open(output_path, 'wb') as output_file:
        pdf_writer.write(output_file)

3. PDF Repair

Automatically detect and repair corrupted PDF files using multiple repair strategies.

Repair strategies (try in order):

Strategy 1: pikepdf (recommended)

import pikepdf

def repair_with_pikepdf(input_path, repaired_path):
    """Repair PDF using pikepdf (requires qpdf)."""
    try:
        with pikepdf.open(input_path) as pdf:
            pdf.save(repaired_path)
        return True
    except Exception:
        return False

Strategy 2: Ghostscript (fallback)

import subprocess
import shutil

def repair_with_ghostscript(input_path, repaired_path):
    """Repair PDF using Ghostscript."""
    gs = shutil.which('gs')
    if not gs:
        return False

    try:
        subprocess.run([
            gs, '-o', repaired_path,
            '-sDEVICE=pdfwrite',
            '-dPDFSETTINGS=/prepress',
            input_path
        ], check=True, capture_output=True)
        return True
    except Exception:
        return False

Usage Examples

Example 1: Extract Signed Agreement Pages from Contract Bundle

# Extract pages 7-8 (indices 6-7) from a contract bundle
extract_pages(
    input_path='/Users/username/Documents/Contracts/Contract_Bundle_2025.pdf',
    output_path='/Users/username/Documents/Contracts/Signed_Agreement.pdf',
    start_page=6,  # 0-indexed
    end_page=7
)

Example 2: Merge Scanned Documents

# Combine multiple scanned pages into one document
merge_pdfs(
    input_paths=[
        '/Users/username/Documents/scan_page1.pdf',
        '/Users/username/Documents/scan_page2.pdf',
        '/Users/username/Documents/scan_page3.pdf'
    ],
    output_path='/Users/username/Documents/complete_document.pdf'
)

Example 3: Repair and Extract

# If PDF is corrupted, repair first then extract
input_file = 'corrupted.pdf'
repaired_file = 'repaired.pdf'

# Try repair
if repair_with_pikepdf(input_file, repaired_file):
    # Now extract from repaired file
    extract_pages(repaired_file, 'output.pdf', 0, 5)
elif repair_with_ghostscript(input_file, repaired_file):
    extract_pages(repaired_file, 'output.pdf', 0, 5)
else:
    print("Repair failed")

Important Guidelines

Page Numbering

• Always use 0-indexed pages in code
• Page 1 in a PDF viewer = index 0 in code
• Page 7 in a PDF viewer = index 6 in code
• When user says "page 7", use index 6

Error Handling

1. Always check if PDF can be opened
2. If opening fails, try repair strategies
3. Validate page ranges before extraction
4. Use open(path, 'rb') for binary reading

File Paths

• Use absolute paths when possible
• Handle spaces in filenames properly
• Check if input files exist before processing
• Ensure output directories exist

Dependencies

Required packages:

pip install PyPDF2>=3.0.0
pip install pikepdf>=8.0.0  # Optional but recommended for repair

System requirements for repair:

• pikepdf: Requires qpdf installed (brew install qpdf on macOS)
• Ghostscript: Requires gs installed (brew install ghostscript on macOS)

Best Practices

1. Always inform the user about:

   • Number of pages in source document
   • Number of pages extracted/merged
   • Whether repair was needed
   • File locations (input and output)

2. Validate before processing:

   • Check if files exist
   • Verify page numbers are within range
   • Ensure output directory is writable

3. Provide detailed feedback:

   print(f"✓ Successfully extracted pages {start_page+1}-{end_page+1}")
   print(f"  Source: {len(pdf_reader.pages)} pages")
   print(f"  Output: {end_page - start_page + 1} pages")
   print(f"  Saved to: {output_path}")
   

4. Handle edge cases:

   • Empty PDFs
   • Single-page PDFs
   • Out-of-range page numbers
   • Corrupted files
   • Encrypted PDFs

Common Workflows

Workflow 1: Quick Page Extraction

User provides document path and page range → Extract → Confirm success

Workflow 2: Merge Multiple Files

User provides list of files → Merge in order → Report total pages

Workflow 3: Batch Processing

User provides pattern/directory → Process all matching files → Summary report

Workflow 4: Repair and Process

Detect corruption → Try pikepdf → Try Ghostscript → Process if repaired

Output Format

When performing PDF operations, provide:

1. Operation summary (what was done)
2. File details (input/output paths, page counts)
3. Any warnings or issues encountered
4. Next steps if applicable

Example output:

✓ PDF Operation Complete

Operation: Extracted pages 7-8 from Tax packet
Input:  /Users/username/Documents/Tax_Packet.pdf (50 pages)
Output: /Users/username/Documents/Tax.pdf (2 pages)
Status: Success (no repair needed)

References

See scripts/pdf_operations.py for the complete implementation with error handling and repair capabilities.

Security Notes

• Never process PDFs from untrusted sources without user awareness
• Be aware that PDF processing can expose embedded malware
• Repair operations may remove certain PDF features (forms, signatures, etc.)
• Always validate file paths to prevent directory traversal