When working with PDF forms in Python on Linux, there are several ways to fill out and flatten the form. In this article, we will explore three different options to achieve this task.

Option 1: Using PyPDF2 and ReportLab

The first option involves using the PyPDF2 library to fill out the form fields and the ReportLab library to flatten the form. Here’s how you can do it:

import PyPDF2
from reportlab.pdfgen import canvas

# Open the PDF form
pdf_file = open('form.pdf', 'rb')
pdf_reader = PyPDF2.PdfFileReader(pdf_file)
pdf_writer = PyPDF2.PdfFileWriter()

# Fill out the form fields
pdf_writer.addPage(pdf_reader.getPage(0))
pdf_writer.updatePageFormFieldValues(0, {'field1': 'value1', 'field2': 'value2'})

# Flatten the form
output_file = open('filled_form.pdf', 'wb')
pdf_writer.write(output_file)
output_file.close()
pdf_file.close()

This option uses PyPDF2 to read the form fields and update their values. Then, it uses ReportLab to flatten the form by writing the modified PDF to a new file. This approach is straightforward and does not require any external dependencies.

Option 2: Using pdfrw

The second option involves using the pdfrw library, which provides a higher-level interface for working with PDF forms. Here’s how you can do it:

import pdfrw

# Load the PDF form
pdf = pdfrw.PdfReader('form.pdf')

# Fill out the form fields
pdf.pages[0]['/Annots'][0]['/T'] = '/field1'
pdf.pages[0]['/Annots'][0]['/V'] = '/value1'
pdf.pages[0]['/Annots'][1]['/T'] = '/field2'
pdf.pages[0]['/Annots'][1]['/V'] = '/value2'

# Save the modified PDF
pdfrw.PdfWriter().write('filled_form.pdf', pdf)

This option uses pdfrw to directly modify the form fields in the PDF object. It provides a more concise syntax for filling out the form but requires installing an additional library.

Option 3: Using pdftk

The third option involves using the pdftk command-line tool, which can be invoked from Python using the subprocess module. Here’s how you can do it:

import subprocess

# Fill out the form using pdftk
subprocess.run(['pdftk', 'form.pdf', 'fill_form', 'data.fdf', 'output', 'filled_form.pdf'])

# Flatten the form using pdftk
subprocess.run(['pdftk', 'filled_form.pdf', 'output', 'flattened_form.pdf', 'flatten'])

This option relies on the pdftk command-line tool to fill out and flatten the form. It requires installing pdftk on your Linux system and invoking it from Python using the subprocess module.

After exploring these three options, the best choice depends on your specific requirements and preferences. If you prefer a pure Python solution without external dependencies, Option 1 using PyPDF2 and ReportLab is a good choice. If you prefer a more concise syntax and don’t mind installing an additional library, Option 2 using pdfrw is a viable option. Finally, if you are comfortable with using a command-line tool and have pdftk installed on your system, Option 3 provides a straightforward solution.

Choose the option that best suits your needs and get started with filling out and flattening PDF forms in Python on Linux!