Tkinter 8.5 reference: a GUI for Python

A number of operations related to themes require that you have available an instance of the ttk.Style() class (in the Python sense of class). For example, to obtain a list of the available themes in your installation:

>>> import ttk
>>> s=ttk.Style()
>>> s.theme_names()
('clam', 'alt', 'default', 'classic')

The .theme_names() method returns a tuple containing the names of the available styles. The 'classic' theme gives you the original, pre-ttk appearance.

To determine which theme you get by default, use the .theme_use() method with no arguments. To change the current theme, call this same method with the desired theme name as the argument:

>>> s.theme_use()
'default'
>>> s.theme_use('alt')
>>> s.theme_use()
'alt'