python Redio Button

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The Radiobutton widget in Tkinter allows you to create a set of mutually exclusive options. This means that users can select only one option at a time from a group of radiobuttons. Radiobuttons are often used in settings menus or questionnaires, where a single choice is required.

Syntax:

w = Radiobutton(parent, options)

• parent: The parent widget in which the radiobutton is placed (such as a window or frame).

• options: These define the appearance and behavior of the radiobutton, which are listed below.

Radiobutton Options:

SN Option Description
1 activebackground Background color of the radiobutton when it has focus.
2 activeforeground Font color of the radiobutton text when it has focus.
3 anchor Specifies the exact position of the text within the radiobutton if there's extra space. Default is CENTER.
4 bg Background color of the radiobutton.
5 bitmap Display a bitmap (graphical) image on the radiobutton instead of text.
6 borderwidth Thickness of the radiobutton border.
7 command Function to be called when the radiobutton’s state changes (when selected).
8 cursor Type of mouse pointer to display when hovering over the radiobutton (e.g., arrow, dot).
9 font Font style of the radiobutton text.
10 fg Foreground (text) color of the radiobutton.
11 height Vertical size of the radiobutton (in lines, not pixels).
12 highlightcolor Color of the radiobutton when it has focus.
13 highlightbackground Color of the radiobutton's highlight when not focused.
14 image Image to display on the radiobutton instead of text.
15 justify How to justify multi-line text. Options: CENTER, LEFT, RIGHT.
16 padx Horizontal padding between the text/image and the radiobutton border.
17 pady Vertical padding between the text/image and the radiobutton border.
18 relief Border style of the radiobutton (e.g., FLAT, RAISED, SUNKEN).
19 selectcolor Background color of the radiobutton when it is selected.
20 selectimage Image to display when the radiobutton is selected.
21 state State of the radiobutton (NORMAL or DISABLED).
22 text Text to display next to the radiobutton.
23 textvariable Variable to control the text dynamically. It is linked to a StringVar.
24 underline Underlines the nth character of the text (default: -1, which means no underline).
25 value The value assigned to the control variable when the radiobutton is selected.
26 variable Control variable (IntVar or StringVar) shared among radiobuttons to keep track of the selected option.
27 width Horizontal size of the radiobutton (in characters, not pixels).
28 wraplength Wraps the text if it exceeds the specified number of characters per line.

Radiobutton Methods:

SN Method Description
1 deselect() Deselects the radiobutton.
2 flash() Flashes the radiobutton between its active and normal colors a few times.
3 invoke() Calls the associated command of the radiobutton (if any).
4 select() Selects the radiobutton.

Example of Using Radiobutton in Tkinter:

from tkinter import *

# Create the main window
root = Tk()
root.title("Radiobutton Example")

# Control variable to store the selected option
selected_option = StringVar(value="Option 1")

# Function to display the selected option
def show_selection():
    print(f"Selected: {selected_option.get()}")

# Create radiobuttons
radiobutton1 = Radiobutton(root, text="Option 1", variable=selected_option, value="Option 1", command=show_selection)
radiobutton1.pack(anchor=W)

radiobutton2 = Radiobutton(root, text="Option 2", variable=selected_option, value="Option 2", command=show_selection)
radiobutton2.pack(anchor=W)

radiobutton3 = Radiobutton(root, text="Option 3", variable=selected_option, value="Option 3", command=show_selection)
radiobutton3.pack(anchor=W)

# Run the Tkinter loop
root.mainloop()

Explanation:

• variable: Tracks the currently selected radiobutton (selected_option).

• value: The value of each radiobutton when selected.

• command: Function (show_selection) called when a radiobutton is clicked, printing the selected option.

This widget is useful for scenarios where users need to make a single choice from multiple options.

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