Работа с окнами, авторизация

class Tools:
 
    #function from accesing
    def authorization(self, name, password):
        flag = 0
        name_pass = str(name) + "|" + str(password) +"\n"
        with open("pass.txt", "r") as read:
            contents = read.readlines()
        for i in contents:
            if i == name_pass:
                flag = 1
        return flag

from tkinter import *
from tools import Tools
from tkinter.messagebox import *
 
 
class GUI:
    #inteface for autorization
 
 
    def main_gui(self):
        root = Tk()
        root.title("main")
 
 
        root.mainloop()
 
 
    def authorization_gui(self):
        root = Tk()
        root.title("AUTHORIZATION")
        root.geometry("450x160")
 
        def exit(event):
            root.destroy()
 
        def open_main(event):
            name = entry_name.get()
            pas = entry_pass.get()
            a = Tools()
            acces = a.authorization(name, pas)
            if acces == 1:
                root.destroy()
                self.main_gui()
            else:
                showerror("Authorization error", "Login or password incorrect")
 
        lbl_name = Label(root, text="LOG:", font =("Ubuntu", 16), padx=20, pady = 10, fg="#4f4f4f")
        lbl_pass = Label(root, text="PASS:", font =("Ubuntu", 16), padx=20, fg="#4f4f4f")
        lbl_name.grid(row=0, column=0, sticky="w")
        lbl_pass.grid(row=1, column=0, sticky="w")
 
        entry_name = Entry(root, width=30, font =("Ubuntu", 16), fg="#4f4f4f")
        entry_pass = Entry(root, width=30, font =("Ubuntu", 16), fg="#4f4f4f")
        entry_name.grid(row=0, column=1, sticky="e")
        entry_pass.grid(row=1, column=1, sticky="e")
 
        btn_cancel = Button(root, text="CANCEL", width=7, font=("Ubuntu", 14), fg="#373636", pady=50)
        btn_accept = Button(root, text="LOGIN", width=7, font=("Ubuntu", 14), fg="#373636", pady=50)
        btn_cancel.grid(row=2, column=0)
        btn_accept.grid(row=2, column=1, sticky="e")
 
        btn_cancel.bind("<Button-1>", exit)
        btn_accept.bind("<Button-1>", open_main)
 
        root.mainloop()