from tkinter import Tk
from tkinter.ttk import Frame, Label, Button

LARGE_FONT = ("Verdana", 12)


class GeoffGUI(Tk):

    def __init__(self, *args, **kwargs):
        Tk.__init__(self, *args, **kwargs)

        container = Frame(self)

        container.pack(side="top", fill="both", expand=True)

        container.grid_rowconfigure(0, weight=1)
        container.grid_columnconfigure(0, weight=1)

        self.frames = {}

        for F in (StartPage, PageOne, PageTwo):
            frame = F(container, self)
            frame.grid(row=0, column=0, sticky="nsew")

            self.frames[F.__name__] = frame

        self.show_frame('StartPage')

    def show_frame(self, cont):
        self.frames[cont].tkraise()


class StartPage(Frame):

    def __init__(self, parent, controller):
        Frame.__init__(self, parent)
        label = Label(self, text="Start Page", font=LARGE_FONT)
        label.pack(padx=10, pady=10)

        button1 = Button(self, text="Visit Page 1", command=lambda: controller.show_frame('PageOne'))
        button1.pack()

        button2 = Button(self, text="Visit Page 2", command=lambda: controller.show_frame('PageTwo'))
        button2.pack()


class PageOne(Frame):

    def __init__(self, parent, controller):
        Frame.__init__(self, parent)
        label = Label(self, text="Page 1", font=LARGE_FONT)
        label.pack(padx=10, pady=10)

        button1 = Button(self, text="Back to Home",
                             command=lambda: controller.show_frame('StartPage'))
        button1.pack()

        button2 = Button(self, text="Visit Page 2",
                             command=lambda: controller.show_frame('PageTwo'))
        button2.pack()


class PageTwo(Frame):

    def __init__(self, parent, controller):
        Frame.__init__(self, parent)
        label = Label(self, text="Page 2", font=LARGE_FONT)
        label.pack(padx=10, pady=10)

        button1 = Button(self, text="Back to Home",
                             command=lambda: controller.show_frame('StartPage'))
        button1.pack()

        button2 = Button(self, text="Visit Page 1",
                             command=lambda: controller.show_frame('PageOne'))
        button2.pack()


app = GeoffGUI()
app.mainloop()