Lundh Fredrik. An Introduction to Tkinter

The Tkinter module (Tk interface) is the standard Python interface to the Tk GUI toolkit
from Scriptics (http://www.scriptics.com) (formerly developed by Sun Labs).
Both Tk and Tkinter are available on most Unix platforms, as well as on Windows and
Macintosh systems. Starting with the 8.0 release, Tk offers native look and feel on all
platforms.
Tkinter consists of a number of modules. The Tk interface is located in a binary module named
_tkinter (this was tkinter in earlier versions). This module contains the low-level interface to
Tk, and should never be used directly by application programmers. It is usually a shared library
(or DLL), but might in some cases be statically linked with the Python interpreter.
In addition to the Tk interface module, Tkinter includes a number of Python modules. The two
most important modules are the Tkinter module itself, and a module called Tkconstants. The
former automatically imports the latter, so to use Tkinter, all you need to do is to import one
module:
import Tkinter
Or, more often:
from Tkinter import *