Tkinter: Create an homepage look like

[PeroPuri]

You will need to set the parent frame to the bottom frame

I've changed it like this:

        self.frames = {}
        for F in (StartPage, PageOne, PageTwo):
            page_name = F.__name__
            frame = F(parent=bottom_box, controller=self)
            self.frames[page_name] = frame

            frame.grid(row=0, column=0, sticky="nsew")

        self.show_frame("StartPage")

but it gives me back this error :

Exception in Tkinter callback
Traceback (most recent call last):
  File "C:\Program Files (x86)\Python38-32\lib\tkinter\__init__.py", line 1883, in __call__
    return self.func(*args)
  File "C:/folder/01.py", line 17, in <lambda>
    button1 = tk.Button(container, text="Go to Page One", command=lambda: controller.show_frame("PageOne"))
NameError: name 'controller' is not defined