Itse1359-1610-gui programming  (Page 18/7)

Table of contents

• Preface
  • What you will learn
  • Viewing tip
    • Figures
    • Listings
• General background information
  • Tk and tkinter
    • What is a GUI?
    • What is TCL?
    • What is TK?
    • What is tkinter?
  • Not the only GUI alternative
  • A big and complex topic
• Discussion and sample code
  • A sample program
  • Will discuss in fragments
    • The root
    • Import statements
    • The calculate function
    • Add a Frame widget
    • The grid geometry manager
    • Columns and rows
    • A sticky situation
    • StringVar
    • The Entry widget
    • The width argument
    • The textvariable argument
    • Make the Entry field visible
    • A sticky demonstration
    • A Label and a Button
    • Three more Label widgets
    • Finishing touches
    • Now back to the calculate function
    • The input value in feet
    • Either save the float or pass
    • Calculate and display the result in meters
    • Make everything run
• Run the program
• Complete program listing
• Miscellaneous

Preface

This module is one in a collection of modules on Python designed for teaching ITSE 1359 Introduction to Scripting Languages: Python at Austin Community College in Austin, TX.

This module is not intended to be a stand-alone tutorial. Instead, it is intended to be an annotated guide to other freely available online resources onthe topic.

What you will learn

You will learn how to create a simple GUI using Python and tkinter .

Viewing tip

I recommend that you open another copy of this module in a separate browser window and use the following links to easily find and view the Figuresand Listings while you are reading about them.

(Note to blind and visually impaired students: the Figures in this module are bitmap images and are probably not accessible using anaudio screen reader or a braille display. The Listings are text and should be accessible. Therefore, this module is only partially accessible to blindstudents.

Because the module is not accessible to blind students, material from thismodule will not be used for assignments and will not be included on tests. However, sighted students are strongly encouraged to study the materialfor their own education. Blind and visually impaired students are also encouraged to learn as much from the module as they can.)

Figures

• Figure 1 . Image of a tkinter test from the command line.
• Figure 2 . Output from Feet to Meters converter program.
• Figure 3 . Output from Listing 1.
• Figure 4 . A sticky demonstration.

Listings

• Listing 1 . The root.
• Listing 2 . Add a Frame widget.
• Listing 3 . StringVar objects.
• Listing 4 . The Entry widget.
• Listing 5 . A Label and a Button.
• Listing 6 . Three more Label widgets.
• Listing 7 . Finishing touches.
• Listing 8 . The calculate function.
• Listing 9 . Complete program listing.

General background information

Tk and tkinter

What is a GUI ?

According to Wikipedia ,

"In computing, a graphical user interface (GUI... sometimes pronounced "gooey" ...) is a type of interface that allows users to interact withelectronic devices through graphical icons and visual indicators such as secondary notation, as opposed to text-based interfaces, typed command labels ortext navigation. GUIs were introduced in reaction to the perceived steep learning curve of command-line interfaces ... which require commands to be typed on the keyboard."