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

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

Markdown → 출판품질 PDF (한국 기본값)

scripts/markdown_to_pdf.py는 playwright(Chromium) 기반 마크다운 → 출판품질 PDF 변환기입니다. 한국 환경에 맞게 A4/25mm 마진/Pretendard 폰트를 기본으로 사용합니다.

한국 기본값

사용법

# 80% 케이스 — 무플래그
python skills/pdf/scripts/markdown_to_pdf.py generate spec.md
# → spec.pdf 생성, stdout에 경로 한 줄

# 출력 경로 지정
python ... markdown_to_pdf.py generate spec.md docs/spec.pdf

# 표지 + TOC 포함 (출판 모드)
python ... markdown_to_pdf.py generate \
  --cover --toc \
  --title "프로젝트 명세서" \
  --author "팀 이름" \
  --org "회사명" \
  spec.md

# 워터마크 (한글/영문 모두 지원)
python ... markdown_to_pdf.py generate --watermark "초안" memo.md
python ... markdown_to_pdf.py generate --watermark "DRAFT" memo.md
python ... markdown_to_pdf.py generate --watermark "대외비" memo.md

# 프리뷰 (HTML 렌더 후 브라우저 자동 오픈, PDF 라운드트립 회피)
python ... markdown_to_pdf.py preview spec.md

# 폰트 미리 다운로드 + 의존성 점검
python ... markdown_to_pdf.py setup

페이지 구성 옵션 (현재 CLI의 질문 방식 권장)

마크다운을 PDF로 만들 때, 다음을 사용자에게 물어보고 적용하세요:

Q1: 표지 페이지를 추가할까요?

• A) 추가 (외부 공유용) → --cover --title "..." --author "..."
• B) 추가 안 함 (내부 메모) → 옵션 없음

Q2: 목차(TOC)를 포함할까요?

• A) 포함 (10페이지 이상이면 추천) → --toc
• B) 포함 안 함 (짧은 문서)

Q3: 워터마크가 필요한가요?

• A) DRAFT/초안 (작업 중) → --watermark "초안"
• B) 대외비/CONFIDENTIAL → --watermark "대외비" --confidential
• C) 없음 (최종본)

Q4: H1마다 새 페이지로 시작?

• A) 예 (장 단위 문서) → 기본값 (옵션 불필요)
• B) 아니오 (메모/단편) → --no-chapter-breaks

옵션 레퍼런스

Output Contract

스크립트 자동화/체이닝을 위한 명확한 출력 규약:

stdout: <output-path>           ← 한 줄, 경로만 (성공 시)
stderr: 진행상황 메시지         ← --quiet로 끔
exit:
  0 = 성공
  1 = 인자 오류 (입력파일 없음/.md 아님)
  2 = 렌더링 실패
  3 = 의존성 누락 (playwright/markdown 미설치)
  4 = 네트워크 실패 (정의됨, 현재 미사용 — 폰트 다운로드 실패는 fallback 처리)

캡처 예시:

PDF=$(python markdown_to_pdf.py generate spec.md 2>/dev/null) && open "$PDF"

의존성 설치

pip install playwright markdown pygments
playwright install chromium     # 첫 실행 시 1회만

왜 playwright? 우리 /minos 스킬이 이미 playwright + Chromium을 사용하므로 의존성이 중복되지 않습니다. Windows/Mac/Linux 모두 동일한 렌더링 결과를 보장하고, GTK 같은 시스템 라이브러리 의존성이 없습니다.

셋업 한 방에:

python skills/pdf/scripts/markdown_to_pdf.py setup
# → 의존성 점검 + Chromium 다운로드 + 한글 폰트 다운로드

폰트는 첫 실행 시 ~/.cache/agent-customizations/fonts/에 자동 다운로드됩니다 (SIL OFL 1.1 라이선스). 오프라인 환경이면 --skip-fonts로 시스템 폰트만 사용 가능합니다.

Clio 통합

/clio 스킬의 Phase 3에서 산출물(PRD/TECHNICAL/USER-MANUAL)을 PDF로 자동 출력할 때 사용됩니다. Clio가 호출하는 명령:

# USER-MANUAL은 표지 + TOC 포함 (외부 공유 빈도 높음)
python markdown_to_pdf.py generate \
  --cover --toc \
  --title "{프로젝트명} 사용자 매뉴얼" \
  USER-MANUAL.md

# PRD/TECHNICAL은 TOC만 (내부 문서)
python markdown_to_pdf.py generate --toc PRD.md
python markdown_to_pdf.py generate --toc TECHNICAL.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
• Markdown → 출판 PDF: 위 섹션 참조 (한국 기본값: A4 + Pretendard)