def __init__(self, master=None, **kw):
        "Initialize the MarkovDemo instance's widgets and settings."
        super().__init__(master, **kw)
        self.build_widgets()
        self.place_widgets()
        self.setup_widgets()
        self.grid_rowconfigure(2, weight=1)
        self.grid_rowconfigure(3, weight=1)
        self.grid_columnconfigure(0, weight=1)
        self.key = self.primer = None
Initialize the MarkovDemo instance's widgets and settings.
recipes/Python/578076_Markov/recipe-578076.py