automate new PDF creation with Bookmarks Based up Regex

[standenman]

I am seeking to create some functionality to recasting a PDF file of medical records. The date of treatment or visit is very important and I will like to bookmark based upon treatment date. So for this particular pdf file, the treatment date appears as "Visit date: 01/01/2010" format. The below code does successfully create the new pdf but does not create any bookmarks. I am a newbie at this - any help would be appreciated:

import PyPDF4
import re

# Open the PDF file for reading
pdf_file = open(r"C:\Users\StanleyDenman\Documents\NewMedical.pdf", 'rb')
pdf_reader = PyPDF4.PdfFileReader(pdf_file)
pdf_writer = PyPDF4.PdfFileWriter()


# Define the regular expression for finding the bookmark locations
regex = re.compile("Visit date: '\b\d{2}/\d{2}/\d{4}\b'")

# Iterate through the pages of the PDF
for i in range(len(pdf_reader.pages)):
    page = pdf_reader.getPage(i)
    text = page.extractText()
    matches = re.findall(regex, text)
    pdf_writer.addPage(page)
    

for match in matches:
   #  Create a bookmark for each match
       bookmark = PyPDF4.pdf.Destination()
       bookmark.page = pdf_writer.addpage()
       bookmark.title = match.group(1)
    

# Write the new PDF file with bookmarks
output_file = open('NewPDF2.pdf', 'wb')
pdf_writer.write(output_file)
output_file.close()
pdf_file.close()

Output:
No error.  but like I said, "newPDF2.pdf" has no bookmarks.  In fact, the file is identifical to C:\Users\StanleyDenman\Documents\NewMedical.pdf