Book Image

Python GUI Programming Cookbook, Second Edition - Second Edition

By : Burkhard Meier
Book Image

Python GUI Programming Cookbook, Second Edition - Second Edition

By: Burkhard Meier

Overview of this book

Python is a multi-domain, interpreted programming language. It is a widely used general-purpose, high-level programming language. It is often used as a scripting language because of its forgiving syntax and compatibility with a wide variety of different eco-systems. Python GUI Programming Cookbook follows a task-based approach to help you create beautiful and very effective GUIs with the least amount of code necessary. This book will guide you through the very basics of creating a fully functional GUI in Python with only a few lines of code. Each and every recipe adds more widgets to the GUIs we are creating. While the cookbook recipes all stand on their own, there is a common theme running through all of them. As our GUIs keep expanding, using more and more widgets, we start to talk to networks, databases, and graphical libraries that greatly enhance our GUI’s functionality. This book is what you need to expand your knowledge on the subject of GUIs, and make sure you’re not missing out in the long run.
Table of Contents (18 chapters)
Title Page
About the Author
About the Reviewer
Customer Feedback

Writing callback functions

At first, callback functions can seem to be a little bit intimidating. You call the function, passing it some arguments, and then the function tells you that it is really very busy and it will call you back!

You wonder: Will this function ever call me back? And how long do I have to wait? In Python, even callback functions are easy and, yes, they usually do call you back. They just have to complete their assigned task first (hey, it was you who coded them in the first place…).

Let's understand a little bit more about what happens when we code callbacks into our GUI. Our GUI is event-driven. After it has been created and displayed onscreen, it typically sits there waiting for an event to happen. It is basically waiting for an event to be sent to it. We can send an event to our GUI by clicking one of its action buttons. This creates an event and, in a sense, we called our GUI by sending it a message.

Now, what is supposed to happen after we send a message to our GUI...