ttk

ttk, short for themed Tk, is a collection of widgets for the Tk GUI toolkit that provides a modern, platform-native appearance. It originated with Tk 8.5 as an upgrade to the classic Tk widget set and is designed to produce consistent visuals across Windows, macOS, and Unix-like systems. In Python, ttk is accessed via the tkinter.ttk module, but the widgets are part of the underlying Tcl/Tk runtime.

Themed widgets differ in appearance from their classic Tk counterparts and are controlled through a styling system. Widgets in ttk are typically prefixed with a T to distinguish them from the standard Tk widgets (for example, TButton, TLabel, TEntry). The look and behavior can be adjusted with a Style object, and the overall look is selected by applying a theme. Themes can be switched at runtime, enabling different aesthetics without changing widget code. The set of built-in themes includes several options such as clam, alt, default, and classic, and platform-specific themes may be provided where available (for example, xpnative on Windows or aqua on macOS).

Widgets provided by ttk cover common interface elements and containers, including buttons, labels, entries, checkbuttons, radiobuttons, comboboxes, notebook (tabbed panels), treeview (hierarchical displays), paned windows, progress bars, scales, separators, and labelframes. The widgets aim to be more visually consistent and easier to theme than their classic Tk counterparts, while remaining compatible with existing Tk layouts and event handling.

ttk remains widely used in GUI applications built with Tcl/Tk or Tkinter, offering a more modern look-and-feel without sacrificing portability.