pdf

name: pdf description: PDF document processing — reading, creating, table extraction, merging/splitting, form handling, watermarking, encryption.

PDF Document Processing

When the user needs to read, create, or manipulate PDF files, follow this guide.

1. Reading PDFs

Quick text extraction

Use the read tool directly — it natively extracts text from PDF files:

read(file_path="report.pdf")

This returns page-by-page text content. Sufficient for most reading tasks.

Table extraction (advanced)

For structured table data, use pdfplumber via a Python script:

import pdfplumber

with pdfplumber.open("report.pdf") as pdf:
    for page in pdf.pages:
        tables = page.extract_tables()
        for table in tables:
            for row in table:
                print(row)

Run this directly with code_execute. Only use write + bash if you need to save the script for reuse.

Image-based / scanned PDFs

If read returns "(No text content)", the PDF is likely image-based. Use OCR:

# Requires: pip install pytesseract pdf2image
from pdf2image import convert_from_path
import pytesseract

images = convert_from_path("scanned.pdf")
for i, img in enumerate(images, 1):
    text = pytesseract.image_to_string(img, lang="chi_sim+eng")
    print(f"--- Page {i} ---")
    print(text)

2. Creating PDFs

Simple text PDFs with reportlab

from reportlab.lib.pagesizes import A4
from reportlab.pdfgen import canvas

c = canvas.Canvas("output.pdf", pagesize=A4)
width, height = A4

c.setFont("Helvetica", 12)
c.drawString(72, height - 72, "Hello, World!")
c.save()

Structured documents with Platypus

For multi-page documents with paragraphs, tables, and images:

from reportlab.lib.pagesizes import A4
from reportlab.lib.styles import getSampleStyleSheet
from reportlab.platypus import SimpleDocTemplate, Paragraph, Spacer, Table, TableStyle
from reportlab.lib import colors
from reportlab.lib.units import inch

doc = SimpleDocTemplate("report.pdf", pagesize=A4)
styles = getSampleStyleSheet()
story = []

# Title
story.append(Paragraph("Quarterly Report", styles["Title"]))
story.append(Spacer(1, 12))

# Body text
story.append(Paragraph("This is the report content.", styles["Normal"]))
story.append(Spacer(1, 12))

# Table
data = [
    ["Quarter", "Revenue", "Growth"],
    ["Q1", "$1.2M", "+5%"],
    ["Q2", "$1.4M", "+17%"],
]
table = Table(data, colWidths=[1.5 * inch, 1.5 * inch, 1.5 * inch])
table.setStyle(TableStyle([
    ("BACKGROUND", (0, 0), (-1, 0), colors.grey),
    ("TEXTCOLOR", (0, 0), (-1, 0), colors.whitesmoke),
    ("GRID", (0, 0), (-1, -1), 1, colors.black),
]))
story.append(table)

doc.build(story)

Important: subscript/superscript

Never use Unicode subscript/superscript characters (like ₂, ³) in reportlab. They cause font errors. Use XML markup instead:

Paragraph("H<sub>2</sub>O and x<super>2</super>", style)

Chinese / CJK text

Register a CJK font before using Chinese text:

from reportlab.pdfbase import pdfmetrics
from reportlab.pdfbase.ttfonts import TTFont

pdfmetrics.registerFont(TTFont("SimSun", "simsun.ttc"))
c.setFont("SimSun", 12)
c.drawString(72, height - 72, "中文文本")

3. Manipulating PDFs

Merge multiple PDFs

from pypdf import PdfWriter

writer = PdfWriter()
for pdf_file in ["part1.pdf", "part2.pdf", "part3.pdf"]:
    writer.append(pdf_file)
writer.write("merged.pdf")
writer.close()

Split / extract pages

from pypdf import PdfReader, PdfWriter

reader = PdfReader("large.pdf")
writer = PdfWriter()

# Extract pages 5-10 (0-indexed)
for page in reader.pages[4:10]:
    writer.add_page(page)
writer.write("pages_5_to_10.pdf")
writer.close()

Rotate pages

from pypdf import PdfReader, PdfWriter

reader = PdfReader("input.pdf")
writer = PdfWriter()
for page in reader.pages:
    page.rotate(90)  # 90, 180, or 270 degrees
    writer.add_page(page)
writer.write("rotated.pdf")
writer.close()

Add watermark

from pypdf import PdfReader, PdfWriter

reader = PdfReader("document.pdf")
watermark = PdfReader("watermark.pdf")
writer = PdfWriter()

for page in reader.pages:
    page.merge_page(watermark.pages[0])
    writer.add_page(page)
writer.write("watermarked.pdf")
writer.close()

Password protection

from pypdf import PdfWriter

writer = PdfWriter()
writer.append("document.pdf")
writer.encrypt(user_password="read_pass", owner_password="admin_pass")
writer.write("encrypted.pdf")
writer.close()

4. PDF form handling

See forms.md for detailed form field extraction and filling.

Quick overview:

• Read form fields: pypdf.PdfReader → reader.get_fields()
• Fill fillable forms: pypdf.PdfWriter → writer.update_page_form_field_values()
• Non-fillable forms: Add text annotations at specific coordinates

5. Quick reference

6. Dependencies

Core (included with Muse):

• pypdf — read, merge, split, rotate, encrypt, forms

Optional (install as needed):

• pdfplumber — table extraction: pip install pdfplumber
• reportlab — PDF creation: pip install reportlab
• pytesseract — OCR: pip install pytesseract (requires Tesseract binary)
• pdf2image — PDF to image: pip install pdf2image (requires Poppler)