How to Create a PDF Generator with Python and ReportLab

Programmatic PDF generation is essential for:

• Invoices and receipts — auto-generate from order data
• Reports — create formatted reports from analytics
• Certificates — batch-produce certificates with dynamic names
• Letters and contracts — mail merge at scale

ReportLab is the most mature Python library for PDF creation. It is open-source, well-documented, and used in production by companies like NASA and Wikipedia.

Install ReportLab via pip:

pip install reportlab

Verify the installation:

import reportlab
print(reportlab.Version)  # Should print 4.x

The simplest possible PDF:

from reportlab.pdfgen import canvas

def create_simple_pdf(filename):
    c = canvas.Canvas(filename)
    c.setFont("Helvetica-Bold", 24)
    c.drawString(72, 750, "Hello, PDF!")
    c.setFont("Helvetica", 14)
    c.drawString(72, 720, "Generated with Python and ReportLab")
    c.save()

create_simple_pdf("hello.pdf")

This creates a single-page PDF with text. The coordinates (72, 750) represent points from the bottom-left corner. 72 points = 1 inch.

Here is a complete invoice generator:

from reportlab.lib.pagesizes import A4
from reportlab.lib.units import mm
from reportlab.lib import colors
from reportlab.platypus import SimpleDocTemplate, Table, TableStyle, Paragraph, Spacer
from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle

def create_invoice(filename, invoice_data):
    doc = SimpleDocTemplate(filename, pagesize=A4,
        topMargin=20*mm, bottomMargin=20*mm,
        leftMargin=20*mm, rightMargin=20*mm)

    styles = getSampleStyleSheet()
    elements = []

    # Title
    title_style = ParagraphStyle("InvoiceTitle", parent=styles["Heading1"],
        fontSize=28, textColor=colors.HexColor("#1a1a2e"))
    elements.append(Paragraph("INVOICE", title_style))
    elements.append(Spacer(1, 10*mm))

    # Invoice details
    details = f"""
    Invoice #: {invoice_data["number"]}

    Date: {invoice_data["date"]}

    Client: {invoice_data["client"]}
    """
    elements.append(Paragraph(details, styles["Normal"]))
    elements.append(Spacer(1, 10*mm))

    # Items table
    table_data = [["Item", "Qty", "Price", "Total"]]
    for item in invoice_data["items"]:
        total = item["qty"] * item["price"]
        table_data.append([item["name"], str(item["qty"]),
            f"${item['price']:.2f}", f"${total:.2f}"])

    grand_total = sum(i["qty"] * i["price"] for i in invoice_data["items"])
    table_data.append(["", "", "Total:", f"${grand_total:.2f}"])

    table = Table(table_data, colWidths=[80*mm, 20*mm, 30*mm, 30*mm])
    table.setStyle(TableStyle([
        ("BACKGROUND", (0, 0), (-1, 0), colors.HexColor("#1a1a2e")),
        ("TEXTCOLOR", (0, 0), (-1, 0), colors.white),
        ("FONTNAME", (0, 0), (-1, 0), "Helvetica-Bold"),
        ("FONTSIZE", (0, 0), (-1, 0), 11),
        ("BOTTOMPADDING", (0, 0), (-1, 0), 8),
        ("GRID", (0, 0), (-1, -1), 0.5, colors.grey),
        ("FONTNAME", (0, -1), (-1, -1), "Helvetica-Bold"),
        ("ALIGN", (1, 0), (-1, -1), "RIGHT"),
    ]))
    elements.append(table)

    doc.build(elements)

# Usage
invoice = {
    "number": "INV-2026-001",
    "date": "March 15, 2026",
    "client": "Acme Corp",
    "items": [
        {"name": "Web Development", "qty": 40, "price": 150.00},
        {"name": "UI Design", "qty": 20, "price": 120.00},
        {"name": "Hosting (Annual)", "qty": 1, "price": 299.00},
    ]
}
create_invoice("invoice.pdf", invoice)

For multi-page documents, add consistent headers and footers:

def header_footer(canvas, doc):
    canvas.saveState()

    # Header
    canvas.setFont("Helvetica-Bold", 10)
    canvas.setFillColor(colors.HexColor("#1a1a2e"))
    canvas.drawString(20*mm, A4[1] - 15*mm, "Your Company Name")
    canvas.setFont("Helvetica", 8)
    canvas.drawRightString(A4[0] - 20*mm, A4[1] - 15*mm, "www.yourcompany.com")
    canvas.line(20*mm, A4[1] - 17*mm, A4[0] - 20*mm, A4[1] - 17*mm)

    # Footer
    canvas.setFont("Helvetica", 8)
    canvas.setFillColor(colors.grey)
    canvas.drawCentredString(A4[0] / 2, 10*mm,
        f"Page {canvas.getPageNumber()}")

    canvas.restoreState()

# Use it when building
doc.build(elements, onFirstPage=header_footer, onLaterPages=header_footer)

Include logos or photos in your PDF:

from reportlab.platypus import Image as RLImage

# Add a logo
logo = RLImage("logo.png", width=40*mm, height=15*mm)
elements.insert(0, logo)  # Add at the beginning

# Add a photo with aspect ratio preserved
from reportlab.lib.utils import ImageReader
img = ImageReader("photo.jpg")
iw, ih = img.getSize()
aspect = ih / iw
photo = RLImage("photo.jpg", width=120*mm, height=120*mm * aspect)
elements.append(photo)

Can ReportLab handle Unicode and non-Latin scripts?

Yes, but you need to register TTF fonts that support those characters. Use pdfmetrics.registerFont() with a Unicode-compatible font file.

How do I convert existing PDFs or modify them?

ReportLab creates new PDFs. To modify existing ones, use PyPDF2 or pikepdf. You can also use Reformat's free online PDF tools for merging, compressing, and converting.

Is ReportLab free?

Yes, the open-source version is free under the BSD license. There is also a commercial version (ReportLab PLUS) with additional features like charts and barcodes.