pdf-custom

name: pdf-custom description: Use this skill whenever the user wants to do anything with PDF files. This includes reading or extracting text/tables from PDFs, combining or merging multiple PDFs into one, splitting PDFs apart, rotating pages, adding watermarks, creating new PDFs, filling PDF forms, encrypting/decrypting PDFs, extracting images, and OCR on scanned PDFs to make them searchable. If the user mentions a .pdf file or asks to produce one, use this skill.

PDF Processing Guide

Intent Router

Load sections based on the task:

• Extract text → "Quick Start" + "pdfplumber - Text and Table Extraction" for layout-aware extraction
• Merge/split/rotate PDFs → "Command-Line Tools" for qpdf or "Python Libraries" for pypdf
• Create PDF from scratch → "reportlab - Create PDFs" section with canvas or Platypus examples
• Fill PDF forms → Read FORMS.md for detailed form-filling patterns
• Scanned PDF / OCR → "Extract Text from Scanned PDFs" for pytesseract workflow
• Advanced operations → "Command-Line Tools" for qpdf, pdftk, or "Python Libraries" for pypdfium2

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

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

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}")
print(f"Subject: {meta.subject}")
print(f"Creator: {meta.creator}")

Rotate Pages

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

import pdfplumber

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

Extract Tables

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

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

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

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:

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)

# 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

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

# Split pages
qpdf input.pdf --pages . 1-5 -- pages1-5.pdf
qpdf input.pdf --pages . 6-10 -- pages6-10.pdf

# Rotate pages
qpdf input.pdf output.pdf --rotate=+90:1  # Rotate page 1 by 90 degrees

# Remove password
qpdf --password=mypassword --decrypt encrypted.pdf decrypted.pdf

pdftk (if available)

# Merge
pdftk file1.pdf file2.pdf cat output merged.pdf

# Split
pdftk input.pdf burst

# Rotate
pdftk input.pdf rotate 1east output rotated.pdf

Common Tasks

Extract Text from Scanned PDFs

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

# Convert PDF to images
images = convert_from_path('scanned.pdf')

# OCR each page
text = ""
for i, image in enumerate(images):
    text += f"Page {i+1}:\n"
    text += pytesseract.image_to_string(image)
    text += "\n\n"

print(text)

Add Watermark

from pypdf import PdfReader, PdfWriter

# Create watermark (or load existing)
watermark = PdfReader("watermark.pdf").pages[0]

# Apply to all pages
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

# Using pdfimages (poppler-utils)
pdfimages -j input.pdf output_prefix

# This extracts all images as output_prefix-000.jpg, output_prefix-001.jpg, etc.

Password Protection

from pypdf import PdfReader, PdfWriter

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

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

# Add password
writer.encrypt("userpassword", "ownerpassword")

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

Quick Reference

Next Steps

• For advanced pypdfium2 usage, see REFERENCE.md
• For JavaScript libraries such as pdf-lib, see REFERENCE.md
• If you need to fill out a PDF form, follow FORMS.md
• For troubleshooting guides, see REFERENCE.md

API Reference

Sources: pypdf docs, pdfplumber GitHub, ReportLab docs

pypdf (version 6.x)

PdfReader

from pypdf import PdfReader

reader = PdfReader("file.pdf")
reader = PdfReader("file.pdf", password="secret")  # Encrypted PDF

PageObject

page = reader.pages[0]
text = page.extract_text()
text = page.extract_text(extraction_mode="layout")  # Preserve layout

Properties: .mediabox, .cropbox, .bleedbox, .trimbox, .artbox, .rotation, .images, .annotations

PdfWriter

from pypdf import PdfWriter

writer = PdfWriter()
writer.add_page(reader.pages[0])
writer.clone_reader_document_root(reader)   # Clone entire document

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

Transformation

from pypdf import Transformation

op = Transformation().rotate(90).translate(tx=50, ty=100).scale(sx=0.5, sy=0.5)
page.add_transformation(op)

pdfplumber

Opening and navigating

import pdfplumber

with pdfplumber.open("file.pdf") as pdf:
    page = pdf.pages[0]
    text = page.extract_text()

pdfplumber.open(path, password=None, laparams=None, unicode_norm=None, strict_metadata=False)

PDF properties

Page properties

Page methods

Character object fields

text, fontname, size, x0, x1, y0, y1, top, bottom, width, height, upright, stroking_color, non_stroking_color, matrix

Table settings (key options)

table_settings = {
    "vertical_strategy": "lines",     # "lines", "lines_strict", "text", "explicit"
    "horizontal_strategy": "lines",   # same options
    "explicit_vertical_lines": [],    # x-coordinates
    "explicit_horizontal_lines": [],  # y-coordinates
    "snap_tolerance": 3,
    "join_tolerance": 3,
    "edge_min_length": 3,
    "min_words_vertical": 3,
    "min_words_horizontal": 1,
    "intersection_tolerance": 3,
    "text_tolerance": 3,
    "text_x_tolerance": 3,
    "text_y_tolerance": 3,
}

ReportLab

Canvas (low-level drawing)

from reportlab.pdfgen import canvas
from reportlab.lib.pagesizes import letter, A4
from reportlab.lib.units import inch, cm, mm

c = canvas.Canvas("output.pdf", pagesize=letter)
width, height = letter   # 612, 792 pts

# Coordinates: origin bottom-left, y increases upward
c.drawString(1*inch, 10*inch, "Hello")
c.drawRightString(7.5*inch, 10*inch, "Right-aligned")
c.drawCentredString(4.25*inch, 10*inch, "Centered")
c.showPage()   # Start new page
c.save()

Built-in fonts: Helvetica, Helvetica-Bold, Helvetica-Oblique, Helvetica-BoldOblique, Times-Roman, Times-Bold, Times-Italic, Times-BoldItalic, Courier, Courier-Bold, Courier-Oblique, Courier-BoldOblique, Symbol, ZapfDingbats

Platypus (high-level layout)

from reportlab.platypus import (
    SimpleDocTemplate, Paragraph, Spacer, PageBreak, KeepTogether,
    Table, TableStyle, Image, HRFlowable, ListFlowable, ListItem
)
from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle
from reportlab.lib import colors
from reportlab.lib.enums import TA_LEFT, TA_CENTER, TA_RIGHT, TA_JUSTIFY

doc = SimpleDocTemplate("report.pdf", pagesize=letter,
                         leftMargin=inch, rightMargin=inch,
                         topMargin=inch, bottomMargin=inch)
styles = getSampleStyleSheet()
story = []
story.append(Paragraph("Title", styles["Title"]))
story.append(Spacer(1, 0.2*inch))
story.append(PageBreak())
doc.build(story)

Built-in styles: Normal, Title, Heading1–Heading6, BodyText, Italic, Bold, BulletList, Definition, Code

ParagraphStyle options

ParagraphStyle(
    name="MyStyle",
    fontName="Helvetica",
    fontSize=12,
    leading=14,           # Line height
    spaceBefore=6,        # pts before paragraph
    spaceAfter=6,
    leftIndent=0,
    rightIndent=0,
    firstLineIndent=0,
    alignment=TA_LEFT,
    textColor=colors.black,
    backColor=None,
    borderWidth=0,
    borderColor=None,
    borderPadding=0,
    borderRadius=None,
)

Platypus Table

data = [["Header 1", "Header 2"], ["Row 1 Col 1", "Row 1 Col 2"]]
t = Table(data, colWidths=[3*inch, 3*inch], rowHeights=None)
t.setStyle(TableStyle([
    ("BACKGROUND", (0,0), (-1,0), colors.grey),
    ("TEXTCOLOR",  (0,0), (-1,0), colors.white),
    ("FONTNAME",   (0,0), (-1,0), "Helvetica-Bold"),
    ("FONTSIZE",   (0,0), (-1,-1), 10),
    ("ALIGN",      (0,0), (-1,-1), "CENTER"),
    ("VALIGN",     (0,0), (-1,-1), "MIDDLE"),
    ("GRID",       (0,0), (-1,-1), 0.5, colors.black),
    ("ROWBACKGROUNDS", (0,1), (-1,-1), [colors.white, colors.lightgrey]),
    ("TOPPADDING", (0,0), (-1,-1), 4),
    ("BOTTOMPADDING", (0,0), (-1,-1), 4),
]))

TableStyle commands use (col, row) tuples; -1 means last.

XML markup in Paragraphs

# Bold, italic, color, links, sub/superscript
Paragraph("<b>Bold</b> and <i>italic</i>", styles["Normal"])
Paragraph('<font color="red" size="14">Red text</font>', styles["Normal"])
Paragraph('x<super>2</super> + H<sub>2</sub>O', styles["Normal"])
Paragraph('<a href="https://example.com">Link</a>', styles["Normal"])

Command-Line Tools (qpdf, pdftk, pdftotext)

qpdf (recommended for merge/split/rotate)

# Merge multiple PDFs
qpdf --empty --pages file1.pdf file2.pdf file3.pdf -- merged.pdf

# Extract page range
qpdf input.pdf --pages . 1-5 -- pages1-5.pdf

# Rotate specific pages (+90, +180, +270, -90, or absolute 0,90,180,270)
qpdf input.pdf output.pdf --rotate=+90:1          # Page 1 only
qpdf input.pdf output.pdf --rotate=90             # All pages

# Decrypt
qpdf --password=secret --decrypt encrypted.pdf out.pdf

# Linearize (optimize for web streaming)
qpdf --linearize input.pdf output.pdf

# Inspect PDF structure
qpdf --check input.pdf
qpdf --json input.pdf | jq .

# Split each page to separate file
qpdf --split-pages input.pdf page-%d.pdf

pdftk

pdftk A=file1.pdf B=file2.pdf cat A B output merged.pdf
pdftk input.pdf burst output page_%04d.pdf
pdftk input.pdf rotate 1-endeast output rotated.pdf    # east=90°, west=270°, south=180°
pdftk input.pdf dump_data > metadata.txt
pdftk input.pdf update_info metadata.txt output updated.pdf

pdftotext (poppler)

pdftotext input.pdf                      # output to input.txt
pdftotext -layout input.pdf output.txt   # Preserve layout spacing
pdftotext -f 1 -l 5 input.pdf out.txt   # Pages 1-5 only
pdftotext -nopgbrk input.pdf out.txt    # No page break characters
pdftotext -enc UTF-8 input.pdf out.txt  # Force encoding

pdfimages (poppler)

pdfimages -j input.pdf prefix            # Extract as JPEG
pdfimages -png input.pdf prefix          # Extract as PNG
pdfimages -f 2 -l 4 input.pdf prefix    # Pages 2-4 only
pdfimages -list input.pdf               # List images without extracting

Page size reference