callingaclassfromafunctiondefinedinanotherclassintkinterpython

this might be a bit silly but I have been working on this part for like 16 hours. I am new in programming python and using class and objects. Can anyone help me out with this block of code? I am trying to call login_window to re-appear in the main frame after calling it from a top-level window. the login_window is a separate class and has been called in show_frame function defined in the Window class. I am trying to call the show_frame function in the submit function defined in signup_window. I am missing something and I can not figure out what?

import tkinter as tk

from tkinter import ttk import sqlite3 from tkinter import messagebox

LARGE_FONT = ('Verdana', 24)

class Window(tk.Tk):

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

    tk.Tk.__init__(self, *args, **kwargs)

    tk.Tk.iconbitmap(self, default='logo.ico')
    tk.Tk.wm_title(self, "Platforuma - IoT")

    container = tk.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 (login_window, signup_window, application_window):
        frame = F(container, self)
        self.frames[F] = frame
        frame.grid(row=0,column=0, sticky='nsew')

    self.show_frame(login_window)

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

class login_window(tk.Frame):

def __init__(self, parent, controller):
    tk.Frame.__init__(self, parent)

    userName_label = ttk.Label(self, text='User Name')
    userName_label.pack(pady=10)

    userName_entry = ttk.Entry(self)
    userName_entry.pack()

    password_label = ttk.Label(self, text='Password')
    password_label.pack(pady=10)

    password_entry = ttk.Entry(self, text='Password', show='*')
    password_entry.pack()

    login_button = ttk.Button(self, text='Log-In', width=10, command=lambda: controller.show_frame(application_window))
    login_button.pack()

    signup_button = ttk.Button(self, text='Sign Up', width=10, command=lambda: controller.show_frame(signup_window))
    signup_button.pack()

class signup_window(tk.Frame):

def __init__(self, parent, controller):
    tk.Frame.__init__(self, parent)

    self.e1_var = tk.StringVar()
    self.e2_var = tk.StringVar()
    self.e3_var = tk.StringVar()

    userName_label = ttk.Label(self, text='User Name')
    userName_label.pack(pady=10)

    userName_entry = ttk.Entry(self, textvariable=self.e1_var)
    userName_entry.pack()

    password_label = ttk.Label(self, text='Password')
    password_label.pack(pady=10)

    password_entry = ttk.Entry(self, text='Password', show='*', textvariable=self.e2_var)
    password_entry.pack()

    confirm_password_label = ttk.Label(self, text='Confirm Password')
    confirm_password_label.pack(pady=10)

    confirm_password_entry = ttk.Entry(self, text='Confirm Password', show='*', textvariable=self.e3_var)
    confirm_password_entry.pack()

    submit_button = ttk.Button(self, text='Submit', width=10, command= self.submit)
    submit_button.place(x=70, y=180)

    login_button = ttk.Button(self, text='Log-In', width=10, command=lambda: controller.show_frame(login_window))
    login_button.place(x=180, y=200)

def submit(self):
    conn = sqlite3.connect('dataentry.db')
    c = conn.cursor()
    c.execute('CREATE TABLE IF NOT EXISTS dataentry(username TEXT, password TEXT, confirmpassword TEXT)')
    e1_val = self.e1_var.get()
    e2_val = self.e2_var.get()
    e3_val = self.e3_var.get()
    c.execute("INSERT INTO dataentry (username, password, confirmpassword) VALUES (?, ?, ?)",
              (e1_val, e2_val, e3_val))
    conn.commit()
    c.close()
    conn.close()
    #messagebox.showinfo("Successfull","Your information is registered. Kindly procede to Login")
    win = tk.Toplevel()
    win.title('Registered')
    message = "Your information is registered. Kindly procede to Login"
    tk.Label(win, text=message).pack()
    tk.Button(win, text='Login', command=lambda: Window.show_frame(Window, login_window)).pack()
    #getting error in the calling the command fuction. Everything else works fine

class application_window(tk.Frame):

def __init__(self, parent, controller):
    tk.Frame.__init__(self, parent)

    window_label = ttk.Label(self, text='Application Window', font= LARGE_FONT)
    window_label.pack(pady=10)

app = Window() app.mainloop()