Book Image

Python GUI Programming with Tkinter, 2nd edition - Second Edition

By : Alan D. Moore
4.5 (2)
Book Image

Python GUI Programming with Tkinter, 2nd edition - Second Edition

4.5 (2)
By: Alan D. Moore

Overview of this book

Tkinter is widely used to build GUIs in Python due to its simplicity. In this book, you’ll discover Tkinter’s strengths and overcome its challenges as you learn to develop fully featured GUI applications. Python GUI Programming with Tkinter, Second Edition, will not only provide you with a working knowledge of the Tkinter GUI library, but also a valuable set of skills that will enable you to plan, implement, and maintain larger applications. You’ll build a full-blown data entry application from scratch, learning how to grow and improve your code in response to continually changing user and business needs. You’ll develop a practical understanding of tools and techniques used to manage this evolving codebase and go beyond the default Tkinter widget capabilities. You’ll implement version control and unit testing, separation of concerns through the MVC design pattern, and object-oriented programming to organize your code more cleanly. You’ll also gain experience with technologies often used in workplace applications, such as SQL databases, network services, and data visualization libraries. Finally, you’ll package your application for wider distribution and tackle the challenge of maintaining cross-platform compatibility.
Table of Contents (22 chapters)
19
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20
Index
Appendices

Tkinter's event queue

As we discussed in Chapter 11, Creating Automated Tests with unittest, many tasks in Tkinter, such as drawing and updating widgets, are done asynchronously rather than taking immediate action when called in code. More specifically, the actions you perform in Tkinter, such as clicking a button, triggering a key bind or trace, or resizing a window, place an event in the event queue. On each iteration of the main loop, Tkinter pulls all outstanding events from the queue and processes them one at a time. For each event, Tkinter executes any tasks (that is, callbacks or internal operations like redrawing widgets) bound to the event before proceeding to the next event in the queue.

Tasks are roughly prioritized by Tkinter as either regular or do-when-idle (often referred to as idle tasks). During event processing, regular tasks are processed first, followed by idle tasks when all the regular tasks are finished. Most drawing or widget-updating tasks are classified...