Add watermark to your PDF file with Python

#python #tutorial #productivity #showdev

Today I will show you how you can simply add a watermark to all pages within a PDF file.
I'll use PyPDF2

A Pure-Python library built as a PDF toolkit. It is capable of:

extracting document information (title, author, …)
splitting documents page by page
merging documents page by page
cropping pages
merging multiple pages into a single page
encrypting and decrypting PDF files
and more!

By being Pure-Python, it should run on any Python platform without any dependencies on external libraries. It can also work entirely on StringIO objects rather than file streams, allowing for PDF manipulation in memory. It is therefore a useful tool for websites that manage or manipulate PDFs.

Let's jump to the code

from PyPDF2 import PdfFileMerger, PdfFileReader, PdfFileWriter

pdf_file = r'C:\Users\Stokry\Desktop\python\pdf\test1.pdf'
watermark = r'C:\Users\Stokry\Desktop\python\pdf\logopdf.pdf'
merged = r'C:\Users\Stokry\Desktop\python\pdf\merged.pdf'

with open(pdf_file, "rb") as input_file, open(watermark, "rb") as watermark_file:
    input_pdf = PdfFileReader(input_file)
    watermark_pdf = PdfFileReader(watermark_file)
    watermark_page = watermark_pdf.getPage(0)

    output = PdfFileWriter()

    for i in range(input_pdf.getNumPages()):
        pdf_page = input_pdf.getPage(i)
        pdf_page.mergePage(watermark_page)
        output.addPage(pdf_page)

    with open(merged, "wb") as merged_file:
        output.write(merged_file)