tkraise and some OOP issues in python GUI(tkinter)

I am a beginner at python with very minimal training on the basics of python and a bit of OOP basics. I was trying to make a GUI that can redirect to multiple pages and I made my GUI as follows:

import tkinter as tk
from tkinter import ttk
from tkinter import messagebox as mx
from PIL import Image, ImageTk
import tkinter.scrolledtext as tkst
  
# Initialize The Planar code Changing Functionality frame 
class PGcodefixer(ttk.Frame):
    def __init__(self, container, controller):
        super().__init__(container)
        self.config(width = 950, height = 587)
        self.controller = controller
        self.pack_propagate(False)
        self.grid_propagate(False)
        self.errflag = 0
        
        # Initialize Labels
        self.img3 = Image.open(r"C:\some\path\here") 
        self.img32 = self.img3.resize((250,250), Image.Resampling.LANCZOS)
        self.img3final = ImageTk.PhotoImage(self.img32)

        # Initialize styling of ttk widgets
        self.style = ttk.Style(self)
        self.style.theme_use("alt") 
        self.style.configure("Heading.TLabel", font = ("Comic Sans MS", "20", "bold"), justify = "center", compound  = "top", background = "#568BFC", foreground = "white")
        self.style.configure("TLabel", font = ("Comic Sans MS", "15", "bold"), justify = "center", compound  = "top", background = "#568BFC", foreground = "white") 
        self.style.configure("TButton", font = ("Comic Sans MS", "11", "bold"), justify = "center", Expand = True, background = "#FCC756", foreground = "white")
        self.style.configure("TEntry", justify = "center", Expand = True, background = "#FCC756", foreground = "Black")
        self.style.configure("TFrame", background = "#568BFC") # Background color in Hexcode

# Initialize The Nonplanar code Changing Functionality frame (Work in progress)
class NPGcodefixer(ttk.Frame):
    def __init__(self,container, controller):
        super().__init__(container)
        self.controller = controller
        self.config(width = 950, height = 587)
        self.pack_propagate(False)
        self.grid_propagate(False)

        # Initialize Labels
        self.img2 = Image.open(r"C:\some\path\here") 
        self.img22 = self.img2.resize((200,200), Image.Resampling.LANCZOS)
        self.img2final = ImageTk.PhotoImage(self.img22) 

        # Initialize the styling of ttk widgets
        self.style = ttk.Style(self)
        self.style.theme_use("alt") 
        self.style.configure("TLabel", font = ("Comic Sans MS", "16", "bold"), justify = "center", compound  = "top", background = "#DDE805", foreground = "white") 
        self.style.configure("TButton", font = ("Comic Sans MS", "11", "bold"), justify = "center", Expand = True, background = "#F57FF1", foreground = "white")
        self.style.configure("TFrame", background = "#DDE805") 

# Initialize The Homepage Frame
class Homepage(ttk.Frame):
    def __init__(self, container, controller):
        super().__init__(container)
        self.controller = controller
        self.config(width = 950, height = 587)
        self.pack_propagate(False)
        self.grid_propagate(False)
            
        # Initialize Labels (The first two lines correspond to how you are supposed to put an image into tkinter using Pillow)
        self.img1 = Image.open(r"C:\some\path\here")
        self.img12 = self.img1.resize((200,200), Image.Resampling.LANCZOS) 
        self.img1final = ImageTk.PhotoImage(self.img12) 
        self.labelh1 = ttk.Label(self, image = self.img1final, text = "Welcome to the Timesaver!\n Select the function you wish to use").place(relx = 0.315, rely = 0.15)
    
        # Initialize Button
        self.buttonh1 = ttk.Button(self, text = "Planar Gcode Compiler", command = controller.showframe(self = App, frame = "PGcodefixer")).place(relx = 0.2255, rely = 0.65)
        self.buttonh2 = ttk.Button(self, text = "Nonplanar Gcode Compiler", command = controller.showframe(self = App, frame = "NPGcodefixer")).place(relx = 0.55, rely = 0.65)
        self.buttonh3 = ttk.Button(self, text = "About", command = self.AboutMsg).place(relx = 0.85, rely = 0.9)

        # Initialize the styling of ttk Widgets
        self.style = ttk.Style(self)
        self.style.theme_use("alt") # To enable the button color to be changed, standard ttk will not allow it.
        self.style.configure("TLabel", font = ("Comic Sans MS", "16", "bold"), justify = "center", compound  = "top", background = "#FFB6C1", foreground = "white") # Compound method for relative positioning of text and Image
        self.style.configure("TButton", font = ("Comic Sans MS", "11", "bold"), justify = "center", Expand = True, background = "#67EB67", foreground = "white")
        self.style.configure("TFrame", background = "#FFB6C1") # Background color in Hexcode

    # Initialize a popup about Window for those interested to know more
    def AboutMsg(self):
        mx.showinfo(title = 'About', message =
                'Multi-Purpose Timesaver ver1.0\n'
                'Designed by X')   

# 5. Initialize App as a class
class App(tk.Tk):
    def __init__(self):
        super().__init__()

        # Initializing Window
        self.title("IMPT - Internship Multi-Purpose Timesaver") # Window Title
        self.geometry("950x587") # Using Golden Ratio, haha. Just the Window Size
        self.resizable(False, False) 
        H = Homepage(self, App).pack()
        P = PGcodefixer(self,App).pack()
        N = NPGcodefixer(self,App).pack()
        self.frames = {"Homepage": H, "PGCodefixer": P, "NPGcodefixer": N}

    def showframe(self, frame):
        if frame in self.frames.keys():
            print("yes")
            self.frames[frame].tkraise(self) #The self was asked for by vscode as positional argument is missing without it.
        else:
            print("no")
            pass

# 6. Bootstrapping the App
if __name__ == "__main__":
    app = App()
    App.showframe("Homepage")
    app.mainloop() 

I am confused about 3 main things, and would greatly appreciate your help with them.

1. How does super(init) container work? especially for the first frame initialized at the top - which class is container being inherited from?

2. Why is the controller and self not recognized in the code(i.e. controller.function is just not executed at all(checked with print statements)

3. related to 2. - I considered initializing a mixin class at the very top to store the tkraise method (among others in the future) and dictionary of frames, but found that to be rather weird(i.e. it would raise some frames(specifically their background colour and button colours), but not their buttons or other widgets which remained the same as that of the previous frame. Is this a possible solution to implement the frame tkraise method, and is my current solution(in terms of methodology) a good one?

   Once again, thank you for your help. A lot of solutions for the tkraise method online have used tk.frame but I haven't found one that uses ttk.frame and so I was quite lost. I am a beginner in terms of programming GUIs (and even to programming in general - I am trying to learn by trial and error) and this is my first major step on tkinter, and so even if you have any tips to provide in terms of structuring my code/bad programming practices(e.g. bad O(n) anywhere? etc.) to avoid that I am making, I would greatly appreciate them as well!

EDIT: Included a couple of missing lines of code showing the implementation of tkraise, and added assignment of controller to the controller class.

EDIT2: Added assignment of controller functions to self as they are methods.

EDIT3: I also realized upon further testing that str(classname) does not equal "classname" and so Ichanged the criteria. owever, upon calling the showframe method from the buttons, it is just not executed for some reason which really confused me.. why does this happen? I wanted to use the type change method (if str(x) in a list of strings to avoid making multiple duplicate instances of the class needlessly. I am now quite lost as to whether my approach is even the right one here to implement tkraise..Please help!!

EDIT4: Took into account Mr Roberts' suggestion to add the instances of frames into a list. But now an AttributeError pops up that self.frames is not an attribute of App, despite being a dictionary initialized within the instance of App in the first place. How do I proceed?

EDIT 5: Fixed the erroneous instance for tkraise as self.frames[frame].tkraise(self) and fixed another typo in import statement

1. How does super(init) work?

Well, that's not what you have. What you have is super().__init__. Your first class (PGcodefixer) inherits from ttk.Frame, so super().__init__ is the same as typing ttk.Frame.__init__. If your class were to inherit from multiple parent classes, the super() processing is more complicated, but if you just derive from one base, the concept is pretty easy.

2. Why is the controller and self not recognized...

You have controller as a parameter to your constructors, but you're not saving that parameter anywhere. If you need it later, you need to do something like self.controller = controller so you can refer to it later.

Remember that self is not magic in any way. It's just a parameter name. By convention, the first parameter in a class method is called self, but like all function parameters, that only lasts for the life of the function. Unlike this is C++, you CAN use another name, but you would earn eternal scorn from the Python community.

3. Mixin for tkraise?

I don't see tkraise in this code, so I'm not sure what you're talking about. Mixins can be a useful way to reduce repetitive typing, but only if the code is truly "universal". If you're adding excepts and special cases, then maybe it isn't such a good idea.

There are few issues in your code:

class Homepage(tk.Frame):
    def __init__(self, container, controller):
        ...
        # Initialize Button
        self.buttonh1 = ttk.Button(self, text = "Planar Gcode Compiler", command = controller.showframe(self = App, frame = "PGcodefixer")).place(relx = 0.2255, rely = 0.65)
        self.buttonh2 = ttk.Button(self, text = "Nonplanar Gcode Compiler", command = controller.showframe(self = App, frame = "NPGcodefixer")).place(relx = 0.55, rely = 0.65)
        self.buttonh3 = ttk.Button(self, text = "About", command = self.AboutMsg).place(relx = 0.85, rely = 0.9)
        ...

In the above code:

• command = controller.showframe(...) will execute controller(...) immediately and assign the result (which is None) to command option, so clicking the button later will do nothing. Use command = lambda: controller.showframe(...) instead
• controller.showframe(self = App, frame = "...") should be controller.showframe("...") instead

class App(tk.Tk):
    def __init__(self):
        ...
        H = Homepage(self, App).pack()
        P = PGcodefixer(self,App).pack()
        N = NPGcodefixer(self,App).pack()
        self.frames = {"Homepage": H, "PGCodefixer": P, "NPGcodefixer": N}
   ...

• H = Homepage(self, App).pack() will assign the result of .pack() to H, so H will be None. Separate the line into two lines: H = Homepage(...) and H.pack() (actually using .pack() here is not the correct layout function for your case). Same for P and N as well.
• Using App as the controller is wrong, use self instead

    def showframe(self, frame):
        if frame in self.frames.keys():
            print("yes")
            self.frames[frame].tkraise(self) #The self was asked for by vscode as positional argument is missing without it.
        else:
            print("no")
            pass

In the above code, self.frames[frame].tkraise(self) should be self.frames[frame].tkraise() instead

So the updated code should be as below:

class Homepage(tk.Frame):
    def __init__(self, container, controller):
        ...
        # Initialize Button
        ### use lambda in command option and pass the class name only to showframe()
        ttk.Button(self, text = "Planar Gcode Compiler", command = lambda: controller.showframe("PGcodefixer")).place(relx = 0.2255, rely = 0.65)
        ttk.Button(self, text = "Nonplanar Gcode Compiler", command = lambda: controller.showframe("NPGcodefixer")).place(relx = 0.55, rely = 0.65)
        ttk.Button(self, text = "About", command = self.AboutMsg).place(relx = 0.85, rely = 0.9)
        ...

    ...

# 5. Initialize App as a class
class App(tk.Tk):
    def __init__(self):
        ...

        # make the widget put at (0, 0) occupy all the available space
        self.rowconfigure(0, weight=1)
        self.columnconfigure(0, weight=1)

        H = Homepage(self, self)  # use self as the controller argument
        P = PGcodefixer(self, self)
        N = NPGcodefixer(self, self)
        self.frames = {"Homepage": H, "PGcodefixer": P, "NPGcodefixer": N}

        # use grid() to overlay frames on top of each other
        H.grid(row=0, column=0, sticky="nsew")
        P.grid(row=0, column=0, sticky="nsew")
        N.grid(row=0, column=0, sticky="nsew")

    def showframe(self, frame):
        if frame in self.frames:   # .keys() is not necessary
            print("yes")
            self.frames[frame].tkraise()  # removed self argument passed to tkraise()
        else:
            print("no")

# 6. Bootstrapping the App
if __name__ == "__main__":
    app = App()
    # use the instance "app" instead of class name "App" to call .showframe(...)
    app.showframe("Homepage")
    app.mainloop()