PDF Processing Guide

Overview

Essential PDF processing operations using Python libraries and command-line tools. For advanced features, JavaScript libraries, and detailed examples, see reference.md. For filling PDF forms, read forms.md and follow its instructions.

Quick Start

from pypdf import PdfReader, PdfWriter

reader = PdfReader("document.pdf")
print(f"Pages: {len(reader.pages)}")

text = ""
for page in reader.pages:
    text += page.extract_text()

Python Libraries

pypdf - Basic Operations

Merge PDFs

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

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

reader = PdfReader("document.pdf")
meta = reader.metadata
print(f"Title: {meta.title}")
print(f"Author: {meta.author}")

Rotate Pages

reader = PdfReader("input.pdf")
writer = PdfWriter()
page = reader.pages[0]
page.rotate(90)
writer.add_page(page)
with open("rotated.pdf", "wb") as output:
    writer.write(output)

pdfplumber - Text and Table Extraction

Extract Text with Layout

import pdfplumber

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

Extract Tables

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:
                df = pd.DataFrame(table[1:], columns=table[0])
                all_tables.append(df)

    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

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

c = canvas.Canvas("hello.pdf", pagesize=letter)
width, height = letter
c.drawString(100, height - 100, "Hello World!")
c.line(100, height - 140, 400, height - 140)
c.save()

Multi-Page with Platypus

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 = []

story.append(Paragraph("Report Title", styles['Title']))
story.append(Spacer(1, 12))
story.append(Paragraph("This is the body of the report. " * 20, styles['Normal']))
story.append(PageBreak())
story.append(Paragraph("Page 2", styles['Heading1']))

doc.build(story)

Subscripts and Superscripts

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

Use ReportLab's XML markup tags in Paragraph objects:

from reportlab.platypus import Paragraph
from reportlab.lib.styles import getSampleStyleSheet
styles = getSampleStyleSheet()

chemical = Paragraph("H<sub>2</sub>O", styles['Normal'])
squared = Paragraph("x<super>2</super> + y<super>2</super>", styles['Normal'])

Command-Line Tools

pdftotext (poppler-utils)

pdftotext input.pdf output.txt
pdftotext -layout input.pdf output.txt
pdftotext -f 1 -l 5 input.pdf output.txt

qpdf

qpdf --empty --pages file1.pdf file2.pdf -- merged.pdf
qpdf input.pdf --pages . 1-5 -- pages1-5.pdf
qpdf input.pdf output.pdf --rotate=+90:1
qpdf --password=mypassword --decrypt encrypted.pdf decrypted.pdf

Common Tasks

OCR Scanned PDFs

import pytesseract
from pdf2image import convert_from_path

images = convert_from_path('scanned.pdf')
text = ""
for i, image in enumerate(images):
    text += f"Page {i+1}:\n"
    text += pytesseract.image_to_string(image)
    text += "\n\n"

Add Watermark

from pypdf import PdfReader, PdfWriter

watermark = PdfReader("watermark.pdf").pages[0]
reader = PdfReader("document.pdf")
writer = PdfWriter()

for page in reader.pages:
    page.merge_page(watermark)
    writer.add_page(page)

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

Extract Images

pdfimages -j input.pdf output_prefix

Password Protection

from pypdf import PdfReader, PdfWriter

reader = PdfReader("input.pdf")
writer = PdfWriter()
for page in reader.pages:
    writer.add_page(page)
writer.encrypt("userpassword", "ownerpassword")
with open("encrypted.pdf", "wb") as output:
    writer.write(output)

Quick Reference

Task	Best Tool	Command/Code
Merge PDFs	pypdf	writer.add_page(page)
Split PDFs	pypdf	One page per file
Extract text	pdfplumber	page.extract_text()
Extract tables	pdfplumber	page.extract_tables()
Create PDFs	reportlab	Canvas or Platypus
Command line merge	qpdf	qpdf --empty --pages ...
OCR scanned PDFs	pytesseract	Convert to image first
Fill PDF forms	pypdf or pdf-lib	See forms.md

Next Steps

• For advanced pypdfium2 usage, see reference.md
• For JavaScript libraries (pdf-lib), see reference.md
• For filling PDF forms, follow instructions in forms.md