## 16.2.1 Using Tix

class `Tix`(screenName[, baseName[, className]])
  Toplevel widget of Tix which represents mostly the main window of an application. It has an associated Tcl interpreter.

  Classes in the `Tix` module subclasses the classes in the `Tkinter` module. The former imports the latter, so to use `Tix` with Tkinter, all you need to do is to import one module. In general, you can just import `Tix`, and replace the toplevel call to `Tkinter.Tk` with `Tix.Tk`:

        import Tix
        from Tkconstants import *
        root = Tix.Tk()

To use `Tix`, you must have the `Tix` widgets installed, usually alongside your installation of the Tk widgets. To test your installation, try the following:

      import Tix
      root = Tix.Tk()
      root.tk.eval('package require Tix')

If this fails, you have a Tk installation problem which must be resolved before proceeding. Use the environment variable TIX_LIBRARY to point to the installed `Tix` library directory, and make sure you have the dynamic object library (tix8183.dll or libtix8183.so) in the same directory that contains your Tk dynamic object library (tk8183.dll or libtk8183.so). The directory with the dynamic object library should also have a file called pkgIndex.tcl (case sensitive), which contains the line:

      package ifneeded Tix 8.1 [list load "[file join $dir tix8183.dll]" Tix]