PDF Processing Guide
Overview
This guide covers PDF transformations — merging, splitting, rotating, watermarking, encrypting, filling forms, extracting images, and OCRing scanned PDFs. Reading text/tables is handled by read_file directly; do NOT use this skill for plain reading. See REFERENCE.md for advanced library usage and FORMS.md for form filling.
Dependencies are pre-installed in the sandbox image — do NOT pip install or npm install anything. Just import or invoke directly.
- Python libraries (always present):
pypdf,pdfplumber,pypdfium2,reportlab,pytesseract,pdf2image,Pillow,pandas,numpy. - JavaScript libraries (always present):
pdf-lib,pdfjs-dist. - CLI tools (present on current sandbox images):
pdftotext/pdftoppm/pdfimages(poppler-utils),qpdf,pdftk,pandoc,tesseract. Older sandbox images may be missing some of these — if a CLI tool returnsnot found, fall back to the equivalent Python library on this page rather than trying to install it.
Reading PDF text — use read_file
For any request to read, summarise, analyse, extract data from, or aggregate the contents of a PDF, call read_file directly:
read_file(path="path/to/document.pdf")
The harness parses PDFs natively via markitdown and returns markdown.
Pagination via offset/limit is free (cached). Do NOT pip install pypdf/pdfplumber/pymupdf or write subprocess extraction scripts for
reading — that bootstrap is exactly what read_file eliminates.
If read_file fails or times out on a specific PDF (large papers,
encrypted, corrupt, or a scanned image-only PDF with no text layer),
fall back in this order:
pypdffirst. It's a pure-Python library that's always importable in the sandbox and doesn't depend on apt packages. Use it to read pages directly — see the snippet below.pdftotext/pandoc(poppler-utils) whenpypdfcan't handle the specific PDF (e.g. tricky encoding). These are CLI tools and may be missing on older sandbox images; ifwhich pdftotexterrors, stay onpypdf.ocr-and-documentsskill for scanned image-only PDFs.
# Reliable fallback when read_file times out — chunk by page range
# so a single call doesn't run past the tool timeout on long papers.
from pypdf import PdfReader
reader = PdfReader("path/to/document.pdf")
print(f"Total pages: {len(reader.pages)}")
for i in range(0, len(reader.pages)):
print(f"--- Page {i + 1} ---")
print(reader.pages[i].extract_text())
The other Python libraries on this page are for transformations (the next sections), not for plain reading.
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 - Layout-aware text + tables (fallback only)
For plain text/markdown, read_file(path) is the right call (see top of
this skill). Use pdfplumber only when you need precise layout
preservation or per-table structured extraction that read_file does
not give you — e.g., multi-line cells, merged headers, or extracting a
specific table on a specific page.
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
# pytesseract + pdf2image are pre-installed; tesseract-ocr is in the
# sandbox image's apt layer. Just import and run.
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
| Task | Best Tool | Command/Code |
|---|---|---|
| Read text / tables / aggregate data | read_file |
read_file(path="document.pdf") |
| Merge PDFs | pypdf | writer.add_page(page) |
| Split PDFs | pypdf | One page per file |
| Layout-precise text / structured tables (fallback) | pdfplumber | page.extract_text() / page.extract_tables() |
| Create PDFs | reportlab | Canvas or Platypus |
| Command line merge | qpdf | qpdf --empty --pages ... |
| OCR scanned PDFs | ocr-and-documents skill or pytesseract |
Convert to image first |
| Fill PDF forms | pdf-lib or pypdf (see FORMS.md) | See FORMS.md |
Next Steps
- For advanced pypdfium2 usage, see REFERENCE.md
- For JavaScript libraries (pdf-lib), see REFERENCE.md
- If you need to fill out a PDF form, follow the instructions in FORMS.md
- For troubleshooting guides, see REFERENCE.md