A fully functional desktop Invoice Generator built with Python. Users fill in a clean GUI form with company and customer details, upload a logo, and generate a professionally styled A4 PDF invoice — all in one click.
Built to demonstrate real-world Python skills: GUI development, PDF generation, layout design, and clean code architecture.
- 📋 Dynamic Form UI — scrollable Tkinter form with 8 input fields
- 🖼️ Logo Upload — browse and embed a company logo directly into the PDF
- 📄 Professional PDF Output — A4-sized invoice with branded color scheme, table layout, header, and footer
- ✍️ Authorized Signatory Section — signature block auto-placed at the bottom right
- 💾 Save As Dialog — user chooses filename and save location at runtime
- 🎨 Branded Design — consistent color theming (
#B00857) across UI and PDF - 🔄 Alternating Row Shading — clean table design with zebra striping in the PDF
| Technology | Purpose |
|---|---|
| Python 3 | Core language |
| Tkinter | Desktop GUI framework |
| ReportLab | PDF generation engine |
| filedialog | Native OS file browser for logo & save path |
| Canvas API | Precise PDF layout and drawing |
The form uses a Tkinter Canvas + Scrollbar pattern instead of a plain Frame — this makes the UI scrollable and responsive regardless of screen size. Layout is handled with grid() for clean alignment across all input fields.
ReportLab's Canvas is used directly (rather than high-level templates) for precise control over every element's position. All coordinates are calculated relative to page_height using the formula page_h - offset, correctly accounting for ReportLab's bottom-left origin system.
The app is structured as a single class (InvoiceGenerator) with clearly separated responsibilities — UI setup in __init__, scroll logic in helper methods, and PDF generation isolated in generate_invoice(). This makes the codebase easy to extend (e.g. adding line items, tax calculation, or database storage).
pip install reportlabpython main.py- Fill in company name, address, city, GST number
- Enter date, contact, customer name, and authorized signatory
- (Optional) Upload a company logo via Browse Files
- Click Generate Invoice → choose save location → done ✅
invoice-generator-python/
│
├── main.py # Main application (GUI + PDF logic)
└── screenshot.png #screenshot
├── README.md
└── .gitignore
- Add line items table (description, qty, rate, total)
- GST/tax auto-calculation
- Invoice number auto-increment
- Save customer data to SQLite database
- Export customer history as Excel report
- Dark mode UI
Chinki Raj
This project was built as part of my Python development portfolio to demonstrate desktop application development, PDF generation, and GUI design skills.