pdf

First check whether the PDF has fillable fields using pypdf's get_fields method. If it does, extract field metadata to JSON and set values with update_page_form_field_values. For non-fillable PDFs, map text entry bounding boxes on rendered page images and add FreeText annotations at those coordinates.

Use pdfplumber's extract_tables method, which detects cell boundaries and returns rows as lists. You can convert the results to pandas DataFrames and export to Excel. Custom table settings like snap_tolerance help with complex layouts.

pypdf handles structural operations like merging, splitting, rotating, encryption, and form field manipulation. pdfplumber specializes in content extraction with precise character coordinates and table detection. They are commonly used together.

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.

Some viewers fail to render form values without appearance streams. Setting set_need_appearances_writer to True in pypdf forces viewers to regenerate field appearances, though it may trigger a save-changes prompt.

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'. It also supports rotation, decryption, and linearization for web streaming.