pdf

Use pdfplumber to extract text with layout preservation and to detect tables via page.extract_tables(). For simple text extraction, pypdf's page.extract_text() or the pdftotext command-line tool also work.

Run the extract_form_structure.py script to detect labels, lines, and checkboxes with coordinates, then define entry bounding boxes in a fields.json file. The fill_pdf_form_with_annotations.py script adds text annotations at those positions.

pypdf is the recommended choice for merging: create a PdfWriter, add pages from each source PdfReader, and write the output. The qpdf command-line tool offers an equivalent merge with qpdf --empty --pages.

Scanned PDFs contain images rather than text layers, so standard parsers return nothing. Convert pages to images with pdf2image, then run pytesseract OCR on each image to recover the text.

ReportLab's built-in fonts lack Unicode subscript and superscript glyphs, so those characters render as solid boxes. Use the <sub> and <super> XML markup tags inside Paragraph objects instead.

Use qpdf with the --password and --decrypt flags to produce a decrypted copy, for example qpdf --password=secret --decrypt encrypted.pdf decrypted.pdf. In Python, pypdf's reader.decrypt() method handles password-protected files.