fill-pdf-form

name	fill_pdf_form
description	Fills a PDF form with provided data. It maps field keys to their respective pages and applies values. It handles multi-line text areas by assigning specific strings to the identified sequential keys. For checkboxes, it uses the precise export values found during inspection. All dates must be formatted as 'xxxx-xx-xx'.

import pypdf

def fill_pdf_form(input_pdf_path: str, output_pdf_path: str, data: dict): """ Fills a PDF form. 'data' should be a flat dictionary where keys match the PDF field names. The function automatically identifies the page for each key and updates it. """ reader = pypdf.PdfReader(input_pdf_path) writer = pypdf.PdfWriter() writer.append_pages_from_reader(reader)

# Create a mapping of field keys to page indices
field_to_page = {}
for page_index, page in enumerate(reader.pages):
    if "/Annots" in page:
        for annot in page["/Annots"]:
            obj = annot.get_object()
            if "/T" in obj:
                field_to_page[obj["/T"]] = page_index

# Group data by page index for update_page_form_field_values
page_updates = {}
for key, value in data.items():
    if key in field_to_page:
        p_idx = field_to_page[key]
        if p_idx not in page_updates:
            page_updates[p_idx] = {}
        page_updates[p_idx][key] = value

# Apply updates page by page
for p_idx, fields in page_updates.items():
    writer.update_page_form_field_values(writer.pages[p_idx], fields)

with open(output_pdf_path, "wb") as output_file:
    writer.write(output_file)