Python GUI Programming (Tkinter)
Python provides various options for developing graphical user interfaces (GUIs). Most important are listed below.
Tkinter: Tkinter is the Python interface to the Tk GUI toolkit shipped with Python. We would look this option in this chapter.
wxPython: This is an open-source Python interface for wxWindows http://wxpython.org.
JPython: JPython is a Python port for Java which gives Python scripts seamless access to Java class libraries on the local machine http://www.jython.org.
There are many other interfaces available, which you can find them on the net.
Tkinter is the standard GUI library for Python. Python when combined with Tkinter provides a fast and easy way to create GUI applications. Tkinter provides a powerful object-oriented interface to the Tk GUI toolkit.
Creating a GUI application using Tkinter is an easy task. All you need to do is perform the following steps −
Import the Tkinter module.
Create the GUI application main window.
Add one or more of the above-mentioned widgets to the GUI application.
Enter the main event loop to take action against each event triggered by the user.
#!/usr/bin/python import tkinter top = tkinter.Tk() # Code to add widgets will go here... top.mainloop()
This would create a following window −
Tkinter provides various controls, such as buttons, labels and text boxes used in a GUI application. These controls are commonly called widgets.
There are currently 15 types of widgets in Tkinter. We present these widgets as well as a brief description in the following table −
|The Button widget is used to display buttons in your application.|
|The Canvas widget is used to draw shapes, such as lines, ovals, polygons and rectangles, in your application.|
|The Checkbutton widget is used to display a number of options as checkboxes. The user can select multiple options at a time.|
|The Entry widget is used to display a single-line text field for accepting values from a user.|
|The Frame widget is used as a container widget to organize other widgets.|
|The Label widget is used to provide a single-line caption for other widgets. It can also contain images.|
|The Listbox widget is used to provide a list of options to a user.|
|The Menubutton widget is used to display menus in your application.|
|The Menu widget is used to provide various commands to a user. These commands are contained inside Menubutton.|
|The Message widget is used to display multiline text fields for accepting values from a user.|
|The Radiobutton widget is used to display a number of options as radio buttons. The user can select only one option at a time.|
|The Scale widget is used to provide a slider widget.|
|The Scrollbar widget is used to add scrolling capability to various widgets, such as list boxes.|
|The Text widget is used to display text in multiple lines.|
|The Toplevel widget is used to provide a separate window container.|
|The Spinbox widget is a variant of the standard Tkinter Entry widget, which can be used to select from a fixed number of values.|
|A PanedWindow is a container widget that may contain any number of panes, arranged horizontally or vertically.|
|A labelframe is a simple container widget. Its primary purpose is to act as a spacer or container for complex window layouts.|
|This module is used to display message boxes in your applications.|
Let us study these widgets in detail −
Let us take a look at how some of their common attributes.such as sizes, colors and fonts are specified.
Let us study them briefly −
All Tkinter widgets have access to specific geometry management methods, which have the purpose of organizing widgets throughout the parent widget area. Tkinter exposes the following geometry manager classes: pack, grid, and place.
The pack() Method - This geometry manager organizes widgets in blocks before placing them in the parent widget.
The grid() Method - This geometry manager organizes widgets in a table-like structure in the parent widget.
The place() Method -This geometry manager organizes widgets by placing them in a specific position in the parent widget.
Let us study the geometry management methods briefly −