pdf

Use pdfplumber to extract text with layout preserved 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 well.

Extract the form structure with pdfplumber to get label and line coordinates, or convert pages to images and visually estimate field positions. Then add text annotations at those bounding boxes using the provided fill script with pypdf FreeText annotations.

Use pypdf for merging, splitting, rotating, and encryption; pdfplumber for text and table extraction; and reportlab for creating new PDFs. For fast page rendering to images, pypdfium2 is recommended.

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

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: merge with 'qpdf --empty --pages file1.pdf file2.pdf -- merged.pdf' and split page ranges with 'qpdf input.pdf --pages . 1-5 -- out.pdf'. The pdftk tool offers similar cat and burst operations.