Pypdf 2 PDF Splitting

2. PDF Splitting

2. PDF Splitting

"""
Split PDF files into separate documents.
"""
from pypdf import PdfReader, PdfWriter
from pathlib import Path
from typing import List, Tuple, Optional

def split_pdf_by_pages(
    input_path: str,
    output_dir: str,
    pages_per_file: int = 1
) -> List[str]:
    """Split PDF into multiple files with specified pages per file."""
    reader = PdfReader(input_path)
    total_pages = len(reader.pages)

    output_path = Path(output_dir)
    output_path.mkdir(parents=True, exist_ok=True)

    input_name = Path(input_path).stem
    created_files = []

    for start in range(0, total_pages, pages_per_file):
        writer = PdfWriter()
        end = min(start + pages_per_file, total_pages)

        for page_num in range(start, end):
            writer.add_page(reader.pages[page_num])

        # Generate output filename
        if pages_per_file == 1:
            output_file = output_path / f"{input_name}_page_{start + 1}.pdf"
        else:
            output_file = output_path / f"{input_name}_pages_{start + 1}-{end}.pdf"

        writer.write(str(output_file))
        created_files.append(str(output_file))

        print(f"Created: {output_file.name}")

    print(f"Split into {len(created_files)} files")
    return created_files


def extract_pages(
    input_path: str,
    output_path: str,
    page_numbers: List[int]
) -> None:
    """Extract specific pages from a PDF.

    Args:
        input_path: Source PDF file
        output_path: Destination file
        page_numbers: List of page numbers (0-indexed)
    """
    reader = PdfReader(input_path)
    writer = PdfWriter()

    for page_num in page_numbers:
        if 0 <= page_num < len(reader.pages):
            writer.add_page(reader.pages[page_num])
            print(f"Extracted page {page_num + 1}")
        else:
            print(f"Warning: Page {page_num + 1} out of range")

    writer.write(output_path)
    print(f"Extracted pages saved to: {output_path}")


def split_by_ranges(
    input_path: str,
    output_dir: str,
    ranges: List[Tuple[int, int, str]]
) -> List[str]:
    """Split PDF by specified page ranges.

    Args:
        input_path: Source PDF file
        output_dir: Output directory
        ranges: List of (start, end, name) tuples
                start and end are 0-indexed
    """
    reader = PdfReader(input_path)
    output_path = Path(output_dir)
    output_path.mkdir(parents=True, exist_ok=True)

    created_files = []

    for start, end, name in ranges:
        writer = PdfWriter()

        for page_num in range(start, min(end, len(reader.pages))):
            writer.add_page(reader.pages[page_num])

        output_file = output_path / f"{name}.pdf"
        writer.write(str(output_file))
        created_files.append(str(output_file))

        print(f"Created: {output_file.name} (pages {start + 1}-{end})")

    return created_files


def split_by_bookmarks(
    input_path: str,
    output_dir: str
) -> List[str]:
    """Split PDF by bookmark (outline) entries."""
    reader = PdfReader(input_path)
    output_path = Path(output_dir)
    output_path.mkdir(parents=True, exist_ok=True)

    if not reader.outline:
        print("No bookmarks found in PDF")
        return []

    created_files = []

    # Get bookmark page numbers
    bookmarks = []
    for item in reader.outline:
        if isinstance(item, list):
            continue  # Skip nested bookmarks
        try:
            page_num = reader.get_destination_page_number(item)
            title = item.title
            bookmarks.append((page_num, title))
        except:
            continue

    # Sort by page number
    bookmarks.sort(key=lambda x: x[0])

    # Add end marker
    bookmarks.append((len(reader.pages), "END"))

    # Create PDFs for each section
    for i in range(len(bookmarks) - 1):
        start_page, title = bookmarks[i]
        end_page = bookmarks[i + 1][0]

        if start_page >= end_page:
            continue

        writer = PdfWriter()
        for page_num in range(start_page, end_page):
            writer.add_page(reader.pages[page_num])

        # Clean filename
        safe_title = "".join(c if c.isalnum() or c in ' -_' else '_' for c in title)
        output_file = output_path / f"{i + 1:02d}_{safe_title}.pdf"

        writer.write(str(output_file))
        created_files.append(str(output_file))

        print(f"Created: {output_file.name}")

    return created_files


# Example usage
# split_pdf_by_pages('large_document.pdf', 'split_output/', pages_per_file=10)
# extract_pages('document.pdf', 'selected_pages.pdf', [0, 4, 9])  # Pages 1, 5, 10
# split_by_ranges('manual.pdf', 'chapters/', [
#     (0, 10, 'chapter_1'),
#     (10, 25, 'chapter_2'),
#     (25, 40, 'chapter_3')
# ])