Download Free Simple Cafe Billing System in Python Using Tkinter GUI with Source code. Python Projects with Source code. Cafe Billing System is a simple project developed in Python. Cafe Billing System contains a Python Script (cafebill.py). Cafe Billing System is a simple GUI based Desktop Application in Tkinter which is user Friendly and very easy to understand. User just has to select the food items, enter the quantity and click on Total Button to view the Price. This Project is very useful for educational purpose.