Modern Python (2025+) uses uv (blazing-fast package manager) with workspaces:
Old approaches read every page object into RAM. Modern pypdf supports and cloning with compression . Modern Python (2025+) uses uv (blazing-fast package manager)
from pypdf import PdfReader, PdfWriter reader = PdfReader("form.pdf") writer = PdfWriter() writer.clone_document_from_reader(reader) writer.update_page_form_field_values( writer.pages[0], {"full_name": "Ada Lovelace", "date": "2026-01-15"} ) with open("filled.pdf", "wb") as f: writer.write(f) Modern Python handles both
from pypdf import PdfWriter, PdfReader writer = PdfWriter() for pdf_path in list_of_pdfs: reader = PdfReader(pdf_path) for page in reader.pages: writer.add_page(page) writer.add_metadata(reader.metadata) # preserves source metadata {"full_name": "Ada Lovelace"
@app.post("/report") async def create_report(data: dict, background_tasks: BackgroundTasks): # offload to thread pool pdf_bytes = await asyncio.to_thread(_generate_report_sync, data) background_tasks.add_task(log_pdf_generation, data["id"]) return Response(pdf_bytes, media_type="application/pdf")
Two standards exist: (simple) and XFA (XML-based, dynamic). Modern Python handles both.
endesive implements PAdES (PDF Advanced Electronic Signatures) – the EU-standard for qualified signatures.