furkangonel PDF Handling SOP
Select the right tool for each PDF job and execute it correctly. Covers text extraction, merging, splitting, HTML-to-PDF conversion, form filling, and scanned PDF (OCR) handling.
When to Use
- User wants to extract text or tables from a PDF
- User wants to merge multiple PDFs into one
- User wants to split a PDF into separate files
- User wants to create a PDF from HTML, Markdown, or data
- User wants to fill fields in a PDF form
- User wants to process a scanned (image-based) PDF
Part 1 — Tool Selection Guide
| Task | Best tool | Install |
|---|---|---|
| Extract text (digital PDF) | pdfplumber |
pip install pdfplumber |
| Extract tables | pdfplumber |
pip install pdfplumber |
| Merge / split / rotate pages | pypdf |
pip install pypdf |
| Create PDF from scratch (programmatic) | reportlab |
pip install reportlab |
| Convert HTML / CSS to PDF | weasyprint |
pip install weasyprint |
| Convert Markdown to PDF | weasyprint + markdown |
pip install weasyprint markdown |
| Fill PDF forms | pypdf or pdfrw |
pip install pypdf |
| Scanned PDF — OCR | pytesseract + pdf2image |
pip install pytesseract pdf2image + system tesseract |
| Encrypt / decrypt | pypdf |
pip install pypdf |
Part 2 — Text Extraction
Digital PDF — Plain Text
import pdfplumber
with pdfplumber.open("document.pdf") as pdf:
for page_num, page in enumerate(pdf.pages, 1):
text = page.extract_text()
if text:
print(f"=== Page {page_num} ===")
print(text)
Extract Text from Specific Pages
with pdfplumber.open("report.pdf") as pdf:
# Pages 2-5 (0-indexed: pages[1:5])
for page in pdf.pages[1:5]:
text = page.extract_text(x_tolerance=3, y_tolerance=3)
print(text)
Extract Text with Coordinates (for layout-aware parsing)
with pdfplumber.open("form.pdf") as pdf:
page = pdf.pages[0]
words = page.extract_words()
for word in words:
print(f" '{word['text']}' at x={word['x0']:.0f}, y={word['top']:.0f}")
Extract All Text to a File
import pdfplumber
def pdf_to_text(input_path, output_path):
with pdfplumber.open(input_path) as pdf:
with open(output_path, "w", encoding="utf-8") as out:
for page in pdf.pages:
text = page.extract_text() or ""
out.write(text)
out.write("\n\n")
print(f"Extracted {len(pdf.pages)} pages to {output_path}")
pdf_to_text("input.pdf", "output.txt")
Part 3 — Table Extraction
import pdfplumber, csv
with pdfplumber.open("report.pdf") as pdf:
all_tables = []
for page in pdf.pages:
tables = page.extract_tables()
for table in tables:
all_tables.extend(table)
# Write to CSV
with open("tables.csv", "w", newline="", encoding="utf-8") as f:
writer = csv.writer(f)
writer.writerows(all_tables)
print(f"Extracted {len(all_tables)} rows")
Fine-tuned Table Extraction
with pdfplumber.open("complex.pdf") as pdf:
page = pdf.pages[0]
table = page.extract_table({
"vertical_strategy": "lines", # "lines", "text", "explicit"
"horizontal_strategy": "lines",
"snap_tolerance": 3,
"join_tolerance": 3,
"edge_min_length": 3,
"min_words_vertical": 1,
})
for row in table:
print(row)
Part 4 — Merge, Split, and Rotate
Merge Multiple PDFs
from pypdf import PdfWriter
writer = PdfWriter()
files = ["chapter1.pdf", "chapter2.pdf", "appendix.pdf"]
for path in files:
writer.append(path)
with open("combined.pdf", "wb") as out:
writer.write(out)
print(f"Merged {len(files)} files → combined.pdf")
Split — Extract a Range of Pages
from pypdf import PdfReader, PdfWriter
reader = PdfReader("large_report.pdf")
writer = PdfWriter()
# Extract pages 3–7 (0-indexed: 2–6)
for page_num in range(2, 7):
writer.add_page(reader.pages[page_num])
with open("pages_3_to_7.pdf", "wb") as out:
writer.write(out)
Split — One File Per Page
from pypdf import PdfReader, PdfWriter
import os
reader = PdfReader("document.pdf")
os.makedirs("pages", exist_ok=True)
for i, page in enumerate(reader.pages):
writer = PdfWriter()
writer.add_page(page)
with open(f"pages/page_{i+1:03d}.pdf", "wb") as out:
writer.write(out)
print(f"Split into {len(reader.pages)} files in pages/")
Rotate Pages
from pypdf import PdfReader, PdfWriter
reader = PdfReader("sideways.pdf")
writer = PdfWriter()
for page in reader.pages:
page.rotate(90) # 90, 180, or 270 degrees
writer.add_page(page)
with open("rotated.pdf", "wb") as out:
writer.write(out)
Part 5 — Create PDFs
HTML / CSS → PDF (weasyprint)
from weasyprint import HTML, CSS
html_content = """
<!DOCTYPE html>
<html>
<head>
<style>
body { font-family: Arial, sans-serif; margin: 40px; }
h1 { color: #2c3e50; border-bottom: 2px solid #3498db; padding-bottom: 8px; }
table { width: 100%; border-collapse: collapse; margin-top: 20px; }
th, td { border: 1px solid #ddd; padding: 8px; text-align: left; }
th { background: #3498db; color: white; }
tr:nth-child(even) { background: #f2f2f2; }
@page { margin: 20mm; }
</style>
</head>
<body>
<h1>Quarterly Report — Q2 2026</h1>
<p>Generated: May 18, 2026</p>
<table>
<tr><th>Item</th><th>Revenue</th><th>Growth</th></tr>
<tr><td>Product A</td><td>$120,000</td><td>+12%</td></tr>
<tr><td>Product B</td><td>$85,000</td><td>+5%</td></tr>
</table>
</body>
</html>
"""
HTML(string=html_content).write_pdf("report.pdf")
print("Created report.pdf")
Markdown → PDF
import markdown
from weasyprint import HTML
with open("README.md", "r") as f:
md_content = f.read()
html_body = markdown.markdown(md_content, extensions=["tables", "fenced_code"])
full_html = f"""<!DOCTYPE html>
<html>
<head>
<style>
body {{ font-family: Georgia, serif; max-width: 800px; margin: 40px auto; }}
code {{ background: #f4f4f4; padding: 2px 4px; border-radius: 3px; font-size: 0.9em; }}
pre {{ background: #f4f4f4; padding: 16px; border-radius: 6px; overflow-x: auto; }}
@page {{ margin: 20mm; }}
</style>
</head>
<body>{html_body}</body>
</html>"""
HTML(string=full_html).write_pdf("output.pdf")
Programmatic PDF with reportlab
from reportlab.lib.pagesizes import A4
from reportlab.lib.units import mm
from reportlab.pdfgen import canvas
def create_invoice(filename, data):
c = canvas.Canvas(filename, pagesize=A4)
width, height = A4
# Header
c.setFont("Helvetica-Bold", 24)
c.drawString(20*mm, height - 30*mm, "INVOICE")
c.setFont("Helvetica", 11)
c.drawString(20*mm, height - 42*mm, f"Invoice #: {data['number']}")
c.drawString(20*mm, height - 50*mm, f"Date: {data['date']}")
# Line items
y = height - 80*mm
c.setFont("Helvetica-Bold", 10)
c.drawString(20*mm, y, "Description")
c.drawString(120*mm, y, "Amount")
y -= 8*mm
c.line(20*mm, y, 190*mm, y)
y -= 6*mm
c.setFont("Helvetica", 10)
for item in data["items"]:
c.drawString(20*mm, y, item["description"])
c.drawRightString(190*mm, y, f"${item['amount']:,.2f}")
y -= 7*mm
# Total
y -= 5*mm
c.line(20*mm, y, 190*mm, y)
y -= 8*mm
c.setFont("Helvetica-Bold", 12)
c.drawString(120*mm, y, "Total:")
c.drawRightString(190*mm, y, f"${data['total']:,.2f}")
c.save()
create_invoice("invoice.pdf", {
"number": "INV-2026-042",
"date": "May 18, 2026",
"items": [
{"description": "Consulting — 10 hours @ $150/hr", "amount": 1500},
{"description": "Setup fee", "amount": 250},
],
"total": 1750,
})
Part 6 — Scanned PDFs (OCR)
Scanned PDFs are images.
pdfplumberreturns no text — you must OCR first.
# System requirements
brew install tesseract # macOS
sudo apt-get install tesseract-ocr # Ubuntu/Debian
pip install pytesseract pdf2image
import pytesseract
from pdf2image import convert_from_path
# Convert PDF pages to images, then OCR each
pages = convert_from_path("scanned.pdf", dpi=300)
full_text = []
for i, page_image in enumerate(pages, 1):
text = pytesseract.image_to_string(page_image, lang="eng")
print(f"=== Page {i} ===")
print(text)
full_text.append(text)
with open("scanned_output.txt", "w", encoding="utf-8") as f:
f.write("\n\n".join(full_text))
Part 7 — Encrypt and Decrypt
from pypdf import PdfReader, PdfWriter
# Encrypt
reader = PdfReader("document.pdf")
writer = PdfWriter()
writer.append_pages_from_reader(reader)
writer.encrypt(user_password="view123", owner_password="admin456", use_128bit=True)
with open("protected.pdf", "wb") as f:
writer.write(f)
# Decrypt
reader = PdfReader("protected.pdf")
if reader.is_encrypted:
reader.decrypt("view123")
writer = PdfWriter()
writer.append_pages_from_reader(reader)
with open("unlocked.pdf", "wb") as f:
writer.write(f)
Common Pitfalls
| Problem | Cause | Fix |
|---|---|---|
extract_text() returns empty string |
Scanned PDF (image-based) | Use OCR (Part 6) |
| Garbled text order | Complex multi-column layout | Try extract_words() with coordinate sorting |
weasyprint missing fonts |
System fonts not found | Install system font packages |
| Table extraction misses columns | Poor line detection | Adjust vertical_strategy to "text" |
| Large PDF slow to process | All pages loaded at once | Process page-by-page in a loop |
Checklist
- Identified whether PDF is digital (has selectable text) or scanned (image)
- Chose correct tool for the task (extraction vs creation vs merge)
- Scanned PDFs routed through OCR pipeline
- For HTML→PDF, tested output at target paper size (A4 or Letter)
- Merged output verified with page count check
- Large PDFs processed page-by-page to avoid memory issues