How to create a full GUI application with Python, SQLite and Tkinter, batteries included.
A complete desktop application - lists, forms, a database - written with Python, Tkinter and SQLite, and nothing else: the standard library only, no dependency to install.
It manages the products, categories and suppliers of a small Northwind-style database. What it is really for is to be read: how such an application is put together, and why.
python3 tkinterlite.py
Python 3 with Tk 8.6. The database, the log and the configuration live beside the program, so
it can be started from any folder. Window size and theme are in tkinterlite.ini.
To watch it work, start it with the trace: the terminal shows, line by line, what the program does and what its variables hold, while you use the window.
python3 tkinterlite.py --trace
To see where the time goes, the profiler of the standard library runs it as it is:
python3 -m cProfile -s cumulative tkinterlite.py
python3 -m unittest discover -s tests -v
unittest, from the standard library. The tests use a database in memory and temporary files:
northwind.sl3 is never touched.
The database is Northwind, the sample database Microsoft has shipped since the 1990s with Access and SQL Server. It describes Northwind Traders, an imaginary company that imports and exports specialty foods from around the world - Chai, Chang, Gustaf's Knäckebröd - with their categories and suppliers. Generations of programmers learned SQL on it. Tkinterlite keeps three of its tables: products, categories and suppliers.
The values come from Microsoft's own script, instnwnd.sql, in
microsoft/sql-server-samples, © Microsoft
Corporation, under the MIT License: see NORTHWIND-LICENSE.txt. Two rows
are Tkinterlite's own: the product Pizza and the category "No assigned".
In 2026 the data were checked against that script, and 27 products and 7 suppliers had drifted over the years. Accented letters had been lost to a wrong encoding - Knäckebröd had become Knackebrod. And in some rows the values had slid into the next column - a category where the supplier should be, the price where the stock should be - the scars of the old code that wrote rows by position. Writing them by name, as Tkinterlite does now, is what prevents it.
To start again from the original data - tkinterlite.sql holds the whole database, schema and
data:
rm northwind.sl3
sqlite3 northwind.sl3 < tkinterlite.sql
- ARCHITECTURE.md: the design, and the one it replaced. Composition instead of a mixin, the Observer, errors that rise to one net, a thread done right with Tkinter.
- HOW_IT_WORKS.md: the program followed while it runs - the start, a click, a save, a window opened twice, an error, a tick of the clock, the exit - method by method.
- CONVENTIONS.md: the rules the code is written by.
A few things are written by hand on purpose - the log, the configuration reader, the Observer, the register of open windows - where the standard library has a module that would do it: this is a project for learning, and a short class shows what those modules do underneath.
Tkinterlite began in spring 2017, and was rewritten in the autumn of 2026. From the first README:
Developend on Debian Release 9 (stretch) 64-bit.
Spring 2017
Hi all, here we are!
tkinterlite, (Tkinter Sqlite) is my personal study on python 3.4.2 tkinter and sqlite, and by the way the beginning of my adventure with git-hub.
enjoy yourself
GNU GPL, version 3 or later. See LICENSE.