Learning Python with Raspberry Pi

Chapter 4

Graphical Programming

IN THE LAST chapter, we dealt a lot with how to handle data, and how to process it. After all, manipulating data is the fundamental job of a computer. You saw how to build a simple text-driven menu to help control the program. However, such interfaces went out of style in the 1980s. They still have a use in some applications, but these days, most people want to use a mouse (or touch screen).

There are modules using three different graphical toolkits that you're likely to come across—Tk, GTK, and Qt. Tk is quite an old fashioned library that is still used, but lacks some modern features. GTK is a popular toolkit, and the one that LXDE (the default Raspbian desktop) is built in. Qt (sometimes pronounced cute) is a toolkit that was originally developed by Nokia for their ill-fated smartphones. Nokia has since sold it to Digia who continues to develop it. Both GTK and Qt are free to use, and to be honest, there's not much to choose between them. This chapter uses Qt because it's a bit more portable and it's a bit better supported.

You'll need to install the pyside module before you can start using it. In LXTerminal, enter the following:

sudo apt-get install python3-pyside

This may take a little while, so you might want to get a cup of tea.

Graphical User Interface (GUI) Programming

Throughout this book you're going to learn that you can create things in Python very easily if you let the right modules take care of the hard work. Graphical User Interface ...