pdflisted

# PDF Processing Guide ## Overview This guide covers essential PDF processing operations using Python libraries and command-line tools. For advanced features, JavaScript libraries, and detailed examples, see REFERENCE.md. If you need to fill out a PDF form, read FORMS.md and follow its instructions. ## Quick Start ```python from pypdf import PdfReader, PdfWriter # Read a PDF reader = PdfReader("document.pdf") print(f"Pages: {len(reader.pages)}") # Extract text text = "" for page in reader.pages: text += page.extract_text() ``` ### CRITICAL: Large PDF Safeguards Before processing any PDF, check its size and page count: ```python import os from pypdf import PdfReader file_path = "document.pdf" size_mb = os.path.getsize(file_path) / (1024 * 1024) reader = PdfReader(file_path) page_count = len(reader.pages) print(f"Size: {size_mb:.1f} MB, Pages: {page_count}") ``` **Rules for large PDFs (>20 pages or >5MB):** - NEVER extract text from ALL pages at once into a single string - Extract only the pages you need: `reader.pages[0:5]` - Process page by page, don't accumulate all text in memory **WARNING — this overflows context on large PDFs:** ```python # BAD: text = "" for page in reader.pages: text += page.extract_text() print(text) # Dumps EVERYTHING ``` **CORRECT:** ```python for i in range(min(5, page_count)): text = reader.pages[i].extract_text() # Process this page immediately ``` ## Python Libraries ### pypdf - Basic Operations #### Merge PDFs ``