pypdf-3-page-rotation-and-transformation

name	pypdf-3-page-rotation-and-transformation
description	Sub-skill of pypdf: 3. Page Rotation and Transformation.
version	1.0.0
category	data
type	reference
scripts_exempt	true

3. Page Rotation and Transformation

3. Page Rotation and Transformation

"""
Rotate, crop, and transform PDF pages.
"""
from pypdf import PdfReader, PdfWriter, Transformation
from pypdf.generic import RectangleObject
from pathlib import Path
from typing import List, Optional

def rotate_pages(
    input_path: str,
    output_path: str,
    rotation: int,
    pages: Optional[List[int]] = None
) -> None:
    """Rotate PDF pages by specified degrees.

    Args:
        input_path: Source PDF file
        output_path: Destination file
        rotation: Rotation in degrees (90, 180, or 270)
        pages: List of page numbers to rotate (0-indexed), None for all
    """
    if rotation not in [90, 180, 270]:
        raise ValueError("Rotation must be 90, 180, or 270 degrees")

    reader = PdfReader(input_path)
    writer = PdfWriter()

    for i, page in enumerate(reader.pages):
        if pages is None or i in pages:
            page.rotate(rotation)
        writer.add_page(page)

    writer.write(output_path)
    print(f"Rotated PDF saved to: {output_path}")


def rotate_landscape_pages(
    input_path: str,
    output_path: str
) -> int:
    """Automatically rotate landscape pages to portrait."""
    reader = PdfReader(input_path)
    writer = PdfWriter()

    rotated_count = 0

    for page in reader.pages:
        # Get page dimensions
        width = float(page.mediabox.width)
        height = float(page.mediabox.height)

        # Rotate if landscape
        if width > height:
            page.rotate(90)
            rotated_count += 1

        writer.add_page(page)

    writer.write(output_path)
    print(f"Rotated {rotated_count} landscape pages")
    return rotated_count


def crop_pages(
    input_path: str,
    output_path: str,
    crop_box: tuple,
    pages: Optional[List[int]] = None
) -> None:
    """Crop PDF pages to specified dimensions.

    Args:
        input_path: Source PDF file
        output_path: Destination file
        crop_box: (left, bottom, right, top) in points (72 points = 1 inch)
        pages: List of page numbers to crop (0-indexed), None for all
    """
    reader = PdfReader(input_path)
    writer = PdfWriter()

    left, bottom, right, top = crop_box

    for i, page in enumerate(reader.pages):
        if pages is None or i in pages:
            page.mediabox = RectangleObject([left, bottom, right, top])
            page.cropbox = RectangleObject([left, bottom, right, top])

        writer.add_page(page)

    writer.write(output_path)
    print(f"Cropped PDF saved to: {output_path}")


def scale_pages(
    input_path: str,
    output_path: str,
    scale_x: float = 1.0,
    scale_y: float = 1.0
) -> None:
    """Scale PDF pages by specified factors."""
    reader = PdfReader(input_path)
    writer = PdfWriter()

    for page in reader.pages:
        # Apply transformation
        op = Transformation().scale(sx=scale_x, sy=scale_y)
        page.add_transformation(op)

        # Update media box
        page.mediabox.lower_left = (
            float(page.mediabox.lower_left[0]) * scale_x,
            float(page.mediabox.lower_left[1]) * scale_y
        )
        page.mediabox.upper_right = (
            float(page.mediabox.upper_right[0]) * scale_x,
            float(page.mediabox.upper_right[1]) * scale_y
        )

        writer.add_page(page)

    writer.write(output_path)
    print(f"Scaled PDF saved to: {output_path}")


def reorder_pages(
    input_path: str,
    output_path: str,
    new_order: List[int]
) -> None:
    """Reorder PDF pages according to specified order.

    Args:
        input_path: Source PDF file
        output_path: Destination file
        new_order: List of page indices in desired order (0-indexed)
    """
    reader = PdfReader(input_path)
    writer = PdfWriter()

    for page_num in new_order:
        if 0 <= page_num < len(reader.pages):
            writer.add_page(reader.pages[page_num])

    writer.write(output_path)
    print(f"Reordered PDF saved to: {output_path}")


# Example usage
# rotate_pages('document.pdf', 'rotated.pdf', 90)
# rotate_pages('document.pdf', 'rotated.pdf', 90, pages=[0, 2, 4])
# crop_pages('document.pdf', 'cropped.pdf', (72, 72, 540, 720))  # 1 inch margins
# reorder_pages('document.pdf', 'reordered.pdf', [2, 0, 1, 4, 3])