How can I split a PDF file by its pages into PDF files of a smaller size with PyPDF2?

Question

I wrote simple python code that gets PDF, goes over its pages using PyPDF2 and saves each page as new PDF file. see page save function here:

from PyPDF2 import PdfReader, PdfWriter


def save_pdf_page(file_name, page_index):
    reader = PdfReader(file_name)
    writer = PdfWriter()
    writer.add_page(reader.pages[page_index])
    writer.remove_links()
    with open(f"output_page{page_index}.pdf", "wb") as fh:
        writer.write(fh)

Surprisingly each page is about the same size as the original PDF file. using removeLinks (taken from here) didn't reduce page size

I found similar question here, saying it may be caused because PyPDF output files are uncompressed.

Is there a way using PyPDF or any other python lib to make each page relatively small as expected?

Answer 1

You are running into this issue: https://github.com/py-pdf/PyPDF2/issues/449

Essentially the are two problems:

1. Every page might need a resource which is shared, eg font information
2. PyPDF2 might not realize if some pages don't need it

Remove links might help. Additionally, you might want to follow the docs to reduce file size:

from PyPDF2 import PdfReader, PdfWriter

reader = PdfReader("test.pdf")
writer = PdfWriter()
for page_num in [2, 3]:
    page = reader.pages[page_num]

    # This is CPU intensive! It ZIPs the contents of the page
    page.compress_content_streams()

    writer.add_page(page)


with open("seperate.pdf", "wb") as fh:
    writer.remove_links()
    writer.write(fh)