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.