work with a pdf in python

import PyPDF2

template = PyPDF2.PdfFileReader(open('C:/Users/11359023/Desktop/deepfake_vee.pdf', 'rb'))
watermark = PyPDF2.PdfFileReader(open('C:/Users/11359023/Desktop/simple.pdf', 'rb'))
output = PyPDF2.PdfFileWriter()

for i in range(template.getNumPages()):
  page = template.getPage(i)
  page.mergePage(watermark.getPage(0))
  output.addPage(page)

  with open('C:/Users/11359023/Desktop/merged.pdf', 'wb') as file:
    output.write(file)

from PyPDF2 import PdfFileMerger, PdfFileReader, PdfFileWriter

pdf_file = "C:/Users/11359023/Desktop/deepfake_vee.pdf"
watermark = "C:/Users/11359023/Desktop/simple.pdf"
merged = "C:/Users/11359023/Desktop/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)

import PyPDF2
pdf_file = "doc.pdf"
watermark = "watermark.pdf"
merged_file = "merged.pdf"
input_file = open(pdf_file,'rb')
input_pdf = PyPDF2.PdfFileReader(input_file)
watermark_file = open(watermark,'rb')
watermark_pdf = PyPDF2.PdfFileReader(watermark_file)
pdf_page = input_pdf.getPage(0)
watermark_page = watermark_pdf.getPage(0)
pdf_page.mergePage(watermark_page)
output = PyPDF2.PdfFileWriter()
output.addPage(pdf_page)
merged_file = open(merged_file,'wb')
output.write(merged_file)
merged_file.close()
watermark_file.close()