Python - Tkinter Button


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The Button widget is used to add buttons in a Python application. These buttons can display text or images that convey the purpose of the buttons. You can attach a function or a method to a button which is called automatically when you click the button.

Syntax

Here is the simple syntax to create this widget −

w = Button ( master, option=value, ... )

Parameters

  • master − This represents the parent window.

  • options − Here is the list of most commonly used options for this widget. These options can be used as key-value pairs separated by commas.

Sr.No. Option & Description
1

activebackground

Background color when the button is under the cursor.

2

activeforeground

Foreground color when the button is under the cursor.

3

bd

Border width in pixels. Default is 2.

4

bg

Normal background color.

5

command

Function or method to be called when the button is clicked.

6

fg

Normal foreground (text) color.

7

font

Text font to be used for the button's label.

8

height

Height of the button in text lines (for textual buttons) or pixels (for images).

9

highlightcolor

The color of the focus highlight when the widget has focus.

10

image

Image to be displayed on the button (instead of text).

11

justify

How to show multiple text lines: LEFT to left-justify each line; CENTER to center them; or RIGHT to right-justify.

12

padx

Additional padding left and right of the text.

13

pady

Additional padding above and below the text.

14

relief

Relief specifies the type of the border. Some of the values are SUNKEN, RAISED, GROOVE, and RIDGE.

15

state

Set this option to DISABLED to gray out the button and make it unresponsive. Has the value ACTIVE when the mouse is over it. Default is NORMAL.

16

underline

Default is -1, meaning that no character of the text on the button will be underlined. If nonnegative, the corresponding text character will be underlined.

17

width

Width of the button in letters (if displaying text) or pixels (if displaying an image).

18

wraplength

If this value is set to a positive number, the text lines will be wrapped to fit within this length.

Methods

Following are commonly used methods for this widget −

Sr.No. Method & Description
1

flash()

Causes the button to flash several times between active and normal colors. Leaves the button in the state it was in originally. Ignored if the button is disabled.

2

invoke()

Calls the button's callback, and returns what that function returns. Has no effect if the button is disabled or there is no callback.

Example

Try the following example yourself −

import Tkinter
import tkMessageBox

top = Tkinter.Tk()

def helloCallBack():
   tkMessageBox.showinfo( "Hello Python", "Hello World")

B = Tkinter.Button(top, text ="Hello", command = helloCallBack)

B.pack()
top.mainloop()

When the above code is executed, it produces the following result −

TK Button
python_gui_programming.htm


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