pdf

First check if the PDF has fillable fields using pypdf's get_fields method. For fillable forms, extract field info to JSON, assign values, and write with PdfWriter. For non-fillable forms, add FreeText annotations at computed coordinates.

Use pdfplumber's extract_tables method, which detects cell boundaries from lines and text positions. Results can be converted to pandas DataFrames and exported to Excel. Custom table settings help with complex layouts.

pypdf handles structural operations like merging, splitting, rotating, encryption, and form field updates. pdfplumber specializes in content extraction with precise coordinates, making it better for text layout analysis and table extraction.

Scanned PDFs contain images without a text layer, so standard parsers return nothing. Convert pages to images with pdf2image, then run pytesseract OCR on each image to recover searchable text.

ReportLab's built-in fonts lack glyphs for Unicode subscript and superscript characters. Use the <sub> and <super> XML markup tags inside Paragraph objects instead of Unicode characters.

Verify your coordinate system matches the fields.json declaration: use pdf_width/pdf_height for PDF coordinates or image_width/image_height for pixel coordinates. Run the bounding box validation script to catch intersecting or undersized entry boxes before filling.