Programming Python, 3rd Edition

Step 5: Adding a GUI

The console-based interface approach of the preceding section works, and it may be sufficient for some users assuming that they are comfortable with typing commands in a console window. With just a little extra work, though, we can add a GUI that is more modern, easier to use and less error prone, and arguably sexier.

GUI Basics

As we’ll see later in this book, a variety of GUI toolkits and builders are available for Python programmers: Tkinter, wxPython, PyQt, PythonCard, Dabo, and more. Of these, Tkinter ships with Python, and it is something of a de facto standard.

Tkinter is a lightweight toolkit and so meshes well with a scripting language such as Python; it’s easy to do basic things with Tkinter, and it’s straightforward to do more advanced things with extensions and OOP-based code. As an added bonus, Tkinter GUIs are portable across Windows, Linux/Unix, and Macintosh; simply copy the source code to the machine on which you wish to use your GUI.

Because Tkinter is designed for scripting, coding GUIs with it is straightforward. We’ll study all of its concepts and tools later in this book. But as a first example, the first program in Tkinter is just a few lines of code, as shown in Example 2-23.

Example 2-23. PP3E\Preview\tkinter001.py

from Tkinter import *
Label(text='Spam').pack( )
mainloop( )

This isn’t the most useful GUI ever coded, but it demonstrates Tkinter basics and it builds the fully functional window shown in Figure 2-1 in just three simple lines ...