Python pyPDF4 code to bookmark pdf based upon date text

[Stan Denman]

I am trying to create a python function that will transform a pdf file. Specifically I want to create bookmarks based upon text in the pdf. The pdf is a set of medical treatment notes from various dates. This particular set of medical records sets out the treatment date in the header in the form of "Visit date: ##/##/####". So I want to create a bookmark for the treatment records for 01/01/2022 for a bookmark titled 01/01/2022, etc.

This code runs and creates a new pdf file, "NewPDF2.pdf", that is identifical to "NewMedical.pdf". However, there are no bookmarks. Cannot figure out what I am doing wrong.

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()

 

[Kuncode]

This code appears to be incorrect in several places. Here are some of the issues:

1. The regular expression to find the visit dates is incorrect. It should be regex = re.compile("Visit date: \d{2}/\d{2}/\d{4}").
2. The group method should not be used in the line bookmark.title = match.group(1). Instead, you can use the match result directly: bookmark.title = match.
3. You are creating a new page for each match using pdf_writer.addpage(), but you are not adding any content to it. This could result in an error.
4. You should also set the bookmark destination using bookmark.dest = pdf_writer.getPage(i).

Here's a corrected version of the code:

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: \d{2}/\d{2}/\d{4}")
 
# 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.title = match
        bookmark.dest = pdf_writer.getPage(i)
        pdf_writer.addBookmark(bookmark)
    
# Write the new PDF file with bookmarks
output_file = open('NewPDF2.pdf', 'wb')
pdf_writer.write(output_file)
output_file.close()
pdf_file.close()