Tkinter Themes

Summary: in this tutorial, you’ll learn how to change the Tkinter theme from one to another.

Introduction to Tkinter ttk themes

In Tkinter, a theme determines the “look & feel” of all the widgets. It’s a collection of styles for all the ttk widgets.

A style specifies the appearance of a widget class e.g., a Button. Each theme comes with a set of styles. It’s possible to change the appearance of widgets by:

• Modifying the built-in styles
• or creatting new styles

Tkinter allows you to change the current theme to another. When you change the current theme to a new one, Tkinter will apply the styles of that theme to all the ttk widgets.

To get the available themes, you use the theme_names() method of the ttk.Style instance.

First, create a new instance of the ttk.Style class:

style = ttk.Style(root)Code language: Python (python)

Second, get the available themes by calling the theme_names() method:

style.theme_names()Code language: Python (python)

To get the current theme, you use the theme_use() method:

current_theme = style.theme_use()Code language: Python (python)

Note that every operating system (OS) such as Windows, macOS, and Linux comes with its own predefined themes. If you use the theme_names() and theme_use() methods on different OS, you’ll get different results.

To change the current theme to a new one, you pass the new theme name to the theme_use() method:

style.theme_use(theme_name)Code language: Python (python)

The following program shows all themes in your system and allows you to change one theme to another:

import tkinter as tk
from tkinter import ttk


class App(tk.Tk):
    def __init__(self):
        super().__init__()

        # root window
        self.title('Theme Demo')
        self.geometry('400x300')
        self.style = ttk.Style(self)

        # label
        label = ttk.Label(self, text='Name:')
        label.grid(column=0, row=0, padx=10, pady=10,  sticky='w')
        # entry
        textbox = ttk.Entry(self)
        textbox.grid(column=1, row=0, padx=10, pady=10,  sticky='w')
        # button
        btn = ttk.Button(self, text='Show')
        btn.grid(column=2, row=0, padx=10, pady=10,  sticky='w')

        # radio button
        self.selected_theme = tk.StringVar()
        theme_frame = ttk.LabelFrame(self, text='Themes')
        theme_frame.grid(padx=10, pady=10, ipadx=20, ipady=20, sticky='w')

        for theme_name in self.style.theme_names():
            rb = ttk.Radiobutton(
                theme_frame,
                text=theme_name,
                value=theme_name,
                variable=self.selected_theme,
                command=self.change_theme)
            rb.pack(expand=True, fill='both')

    def change_theme(self):
        self.style.theme_use(self.selected_theme.get())


if __name__ == "__main__":
    app = App()
    app.mainloop()
Code language: Python (python)

In this example, when you select a theme from the radio button list, the change_theme() method will apply the selected theme.

If you run the program on Windows 10, you’ll see the following window:

If you change the theme to classic, you’ll see the style of the widgets (Label, Entry, Button, LabelFrame, and Radio Button) change to the following:

Summary

• Create an instance of the ttk.Style class to access the style database.
• Use the style.theme_names() method to get available themes from the Operating System on which the Tkinter application is running.
• Use the style.theme_use() method to change the current theme to a new one.