Tkinter’s Radiobutton widget offers a user-friendly way to present a set of mutually exclusive options. This tutorial explores its functionalities, guiding you through creating, customizing, and responding to user selections.
Table of Contents:
1. Creating Radio Buttons
To create radio buttons, each needs to be linked to a shared variable (typically a StringVar). This ensures only one button within the group can be selected at a time. Here’s how to create a basic set:
import tkinter as tk
root = tk.Tk()
root.title("Tkinter Radiobutton Example")
selected_option = tk.StringVar(value="Option A")
radio_button_a = tk.Radiobutton(root, text="Option A", variable=selected_option, value="Option A")
radio_button_a.pack(anchor=tk.W)
radio_button_b = tk.Radiobutton(root, text="Option B", variable=selected_option, value="Option B")
radio_button_b.pack(anchor=tk.W)
radio_button_c = tk.Radiobutton(root, text="Option C", variable=selected_option, value="Option C")
radio_button_c.pack(anchor=tk.W)
root.mainloop()
This code creates three radio buttons. The variable argument links them, and the value attribute assigns a value to each button’s selection.
2. Retrieving Selected Values
Accessing the selected value is straightforward. Simply use the get() method on the shared variable:
import tkinter as tk
root = tk.Tk()
root.title("Get Radiobutton Value")
selected_option = tk.StringVar(value="Option A")
# ... (Radiobutton creation as above) ...
def get_selected():
print(f"Selected option: {selected_option.get()}")
button = tk.Button(root, text="Get Value", command=get_selected)
button.pack()
root.mainloop()
This example adds a button that prints the selected option when clicked. The get() method retrieves the current value of the StringVar.
3. Customizing Appearance
You can modify the radio button’s visual aspects. For instance, the indicatoron option controls the indicator’s visibility, and selectcolor changes the color when selected:
import tkinter as tk
root = tk.Tk()
root.title("Customize Radiobutton Appearance")
selected_option = tk.StringVar(value="Option A")
radio_button_a = tk.Radiobutton(root, text="Option A", variable=selected_option, value="Option A", indicatoron=False, selectcolor="lightgreen")
radio_button_a.pack(anchor=tk.W)
radio_button_b = tk.Radiobutton(root, text="Option B", variable=selected_option, value="Option B", selectcolor="lightblue")
radio_button_b.pack(anchor=tk.W)
root.mainloop()
This shows how to hide the indicator and change the selection color. Experiment with other styles to achieve your desired look.
4. Using Callback Functions
For a cleaner and more responsive approach, use the command option to directly bind a function to each radio button:
import tkinter as tk
root = tk.Tk()
root.title("Radiobutton Callback")
def option_selected():
print(f"Selected option: {selected_option.get()}")
selected_option = tk.StringVar(value="Option A")
radio_button_a = tk.Radiobutton(root, text="Option A", variable=selected_option, value="Option A", command=option_selected)
radio_button_a.pack(anchor=tk.W)
radio_button_b = tk.Radiobutton(root, text="Option B", variable=selected_option, value="Option B", command=option_selected)
radio_button_b.pack(anchor=tk.W)
root.mainloop()
This method executes option_selected whenever a button is selected, providing a more efficient and elegant solution for handling user interactions.