Pdf

# 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() ```

## Python Libraries

### pypdf - Basic Operations

#### Merge PDFs ```python from pypdf import PdfWriter, PdfReader

writer = PdfWriter() for pdf_file in ["doc1.pdf", "doc2.pdf", "doc3.pdf"]: reader = PdfReader(pdf_file) for page in reader.pages: writer.add_page(page)

with open("merged.pdf", "wb") as output: writer.write(output) ```

#### Split PDF ```python reader = PdfReader("input.pdf") for i, page in enumerate(reader.pages): writer = PdfWriter() writer.add_page(page) with open(f"page_{i+1}.pdf", "wb") as output: writer.write(output) ```

#### Extract Metadata ```python reader = PdfReader("document.pdf") meta = reader.metadata print(f"Title: {meta.title}") print(f"Author: {meta.author}") print(f"Subject: {meta.subject}") print(f"Creator: {meta.creator}") ```

#### Rotate Pages ```python reader = PdfReader("input.pdf") writer = PdfWriter()

page = reader.pages[0] page.rotate(90) # Rotate 90 degrees clockwise writer.add_page(page)

with open("rotated.pdf", "wb") as output: writer.write(output) ```

### pdfplumber - Text and Table Extraction

#### Extract Text with Layout ```python import pdfplumber

with pdfplumber.open("document.pdf") as pdf: for page in pdf.pages: text = page.extract_text() print(text) ```

#### Extract Tables ```python with pdfplumber.open("document.pdf") as pdf: for i, page in enumerate(pdf.pages): tables = page.extract_tables() for j, table in enumerate(tables): print(f"Table {j+1} on page {i+1}:") for row in table: print(row) ```

#### Advanced Table Extraction ```python import pandas as pd

with pdfplumber.open("document.pdf") as pdf: all_tables = [] for page in pdf.pages: tables = page.extract_tables() for table in tables: if table: # Check if table is not empty df = pd.DataFrame(table[1:], columns=table[0]) all_tables.append(df)

# Combine all tables if all_tables: combined_df = pd.concat(all_tables, ignore_index=True) combined_df.to_excel("extracted_tables.xlsx", index=False) ```

### reportlab - Create PDFs

#### Basic PDF Creation ```python from reportlab.lib.pagesizes import letter from reportlab.pdfgen import canvas

c = canvas.Canvas("hello.pdf", pagesize=letter) width, height = letter

# Add text c.drawString(100, height - 100, "Hello World!") c.drawString(100, height - 120, "This is a PDF created with reportlab")

# Add a line c.line(100, height - 140, 400, height - 140)

# Save c.save() ```

#### Create PDF with Multiple Pages ```python from reportlab.lib.pagesizes import letter from reportlab.platypus import SimpleDocTemplate, Paragraph, Spacer, PageBreak from reportlab.lib.styles import getSampleStyleSheet

doc = SimpleDocTemplate("report.pdf", pagesize=letter) styles = getSampleStyleSheet() story = []

# Add content title = Paragraph("Report Title", styles['Title']) story.append(title) story.append(Spacer(1, 12))

body = Paragraph("This is the body of the report. " * 20, styles['Normal']) story.append(body) story.append(PageBreak())

# Page 2 story.append(Paragraph("Page 2", styles['Heading1'])) story.append(Paragraph("Content for page 2", styles['Normal']))

# Build PDF doc.build(story) ```

#### Subscripts and Superscripts

**IMPORTANT**: Never use Unicode subscript/superscript characters (₀₁₂₃₄₅₆₇₈₉, ⁰¹²³⁴⁵⁶⁷⁸⁹) in ReportLab PDFs. The built-in fonts do not include these glyphs, causing them to render as solid black boxes.

Instead, use ReportLab's XML markup tags in Paragraph objects: ```python from reportlab.platypus import Paragraph from reportlab.lib.styles import getSampleStyleSheet

styles = getSampleStyleSheet()

# Subscripts: use <sub> tag chemical = Paragraph("H<sub>2</sub>O", styles['Normal'])

# Superscripts: use <super> tag squared = Paragraph("x<super>2</super> + y<super>2</super>", styles['Normal']) ```

For canvas-drawn text (not Paragraph objects), manually adjust font the size and position rather than using Unicode subscripts/superscripts.

## Command-Line Tools

### pdftotext (poppler-utils) ```bash # Extract text pdftotext input.pdf output.txt

# Extract text preserving layout pdftotext -layout input.pdf output.txt

# Extract specific pages pdftotext -f 1 -l 5 input.pdf output.txt # Pages 1-5 ```

### qpdf ```bash # Merge PDFs qpdf --empty --pages file1.pdf file2.pdf -- merged.pdf

# Split pages qpdf input.pdf --p