Changing Page Size with Python

Aspose.PDF for Python via .NET lets you change PDF page size with simple lines of code. This topic shows how to update page dimensions using the Document and Page APIs.

Please note that the height and width properties use points as basic unit, where 1 inch = 72 points and 1 cm = 1/2.54 inch = 0.3937 inch = 28.3 points.

Set the Page Size of a PDF Page to A4

The example updates the size of the first page in a PDF document to standard A4 dimensions. It also prints the page’s box dimensions (CropBox, TrimBox, ArtBox, BleedBox, MediaBox) before and after resizing so you can verify the changes.

The following code snippet shows how to change the PDF page dimensions to A4 size:

1. Access the first Page of the Document.
2. Display the page’s box sizes before modification (CropBox, TrimBox, ArtBox, BleedBox, MediaBox).
3. Apply A4 dimensions (597.6 × 842.4 points) using the page API.
4. Display the updated page box sizes.
5. Save the modified Document to the specified output path.

import os
import aspose.pdf as ap

# Global configuration
DATA_DIR = "your path here"

def set_page_size(input_file_name, output_file_name):
    """
    Set the size of the first page in the PDF document to A4 and save the updated document.

    Parameters:
    - input_file_name (str): Path to the input PDF file.
    - output_file_name (str): Path to save the output PDF file.
    """
    # Open the PDF document using the Document class
    document = ap.Document(input_file_name)
    # Get particular page (Page API)
    page = document.pages[1]

    # Set the page size as A4 (8.3 x 11.7 in). In Aspose.PDF 1 inch = 72 points.
    # A4 dimensions in points are (597.6, 842.4) for portrait orientation
    print("Before set")
    print(f"CropBox: {page.crop_box.width} x {page.crop_box.height}")
    print(f"TrimBox: {page.trim_box.width} x {page.trim_box.height}")
    print(f"ArtBox: {page.art_box.width} x {page.art_box.height}")
    print(f"BleedBox: {page.bleed_box.width} x {page.bleed_box.height}")
    print(f"MediaBox: {page.media_box.width} x {page.media_box.height}")

    # Use the Page API to set page size
    page.set_page_size(597.6, 842.4)
    print("After set")
    print(f"CropBox: {page.crop_box.width} x {page.crop_box.height}")
    print(f"TrimBox: {page.trim_box.width} x {page.trim_box.height}")
    print(f"ArtBox: {page.art_box.width} x {page.art_box.height}")
    print(f"BleedBox: {page.bleed_box.width} x {page.bleed_box.height}")
    print(f"MediaBox: {page.media_box.width} x {page.media_box.height}")

    # Save the updated document
    document.save(output_file_name)

Get PDF Page Size

This snippet reads a PDF and retrieves the dimensions (width and height) of the first page. It uses the Page API to extract the page’s bounding Rectangle and prints its size to the console. This is useful for inspecting page layout, verifying formats, or preparing documents for further processing.

1. Load the PDF as a Document.
2. Access the first Page.
3. Retrieve the page’s bounding rectangle using get_page_rect().
4. Extract the width and height values.
5. Print the page dimensions.

import os
import aspose.pdf as ap

# Global configuration
DATA_DIR = "your path here"

def get_page_size(input_file_name, output_file_name):
    # Open document (Document API)
    document = ap.Document(input_file_name)

    # Get particular page (Page API)
    page = document.pages[1]
    rectangle = page.get_page_rect(True)
    print(f"{rectangle.width} : {rectangle.height}")

Get PDF Page Size Before and After Rotation

Retrieve the dimensions of a PDF page before and after applying a 90° rotation. This demonstrates how rotation affects width and height and how to use get_page_rect() with or without rotation consideration.

1. Open the PDF as a Document.
2. Access the first Page.
3. Apply a 90° rotation using page.rotate = ap.Rotation.ON90 (see the Rotation enum).
4. Retrieve the page rectangle without rotation using get_page_rect(False) and print its width and height.
5. Retrieve the page rectangle considering rotation using get_page_rect(True) and print its width and height.
6. Compare how the dimensions change due to rotation.

import os
import aspose.pdf as ap

# Global configuration
DATA_DIR = "your path here"

def get_page_size_rotation(input_file_name, output_file_name):
    # Open document (Document API)
    document = ap.Document(input_file_name)
    # Get particular page (Page API)
    page = document.pages[1]
    # Apply rotation using Rotation enum
    page.rotate = ap.Rotation.ON90
    rectangle = page.get_page_rect(False)
    print(f"{rectangle.width} : {rectangle.height}")
    rectangle = page.get_page_rect(True)
    print(f"{rectangle.width} : {rectangle.height}")