How to open a Ui_MainWindow file, inside my main.py (PYQT6)

Question

how do I create a main.py file, where it will access the child files (screen, login, registration).

first it will open the login screen, and then it will open the main screen.

I made the whole project in pyqt6, and converted to py file.

The way I tried to do it below, it just gives an undefined variable error

from PySide6.QtCore import QCoreApplication
from PySide6.QtWidgets import (QApplication, QMainWindow)
from PyQt6.QtWidgets import QApplication, QMessageBox, QDialog, QMainWindow, QPushButton
from PyQt6.QtCore import QProcess
import os,sys,re,time,requests,pywhatkit,smtplib

from tela import Ui_MainWindow
from additem import Ui_MainWindowIsertBox
from login import Ui_MainWindowAcesso

#MAIN SCREEN CLASS
class telaprincipal(QMainWindow, Ui_MainWindow): #tela
    def __init__(self,*args,**argvs):
        super(telaprincipal,self).__init__(*args,**argvs)
        self.ui = Ui_MainWindow()
        self.ui.setupUi(self)
        self.ui.actionProduto.triggered.connect(self.add)

    def add(self):
        add = cadastrar()
        add.exec_()

#CLASS REGISTER ITEMS
class cadastrar(MainWindowIsertBox): #additem
    def __init__(self,*args,**argvs):
        super(cadastrar,self).__init__(*args,**argvs)
        self.ui = Ui_MainWindowIsertBox()
        self.ui.setupUi(self)

        
#CLASS FOR USER LOG IN
class login(MainWindowAcesso): #login
    def __init__(self,*args,**argvs):
        super(login,self).__init__(*args,**argvs)
        self.ui = Ui_MainWindowAcesso()
        self.ui.setupUi(self)
        self.ui.botao_confirmar_acesso.clicked.connext(self.login)

    def login(self):
        admin = "admin"
        senha = "admin"
        
        user = self.ui.label_inserir_user.text()
        passwd = self.ui.label_inserir_senha.text()
        
        if user == admin and passwd == senha:
            QMessageBox.information(QMessageBox(),"login realizado", "Logged")
            window = telaprincipal()
            window.show()
        else:
            QMessageBox.information(QMessageBox(),"login não realizado", "Logged Failed")


#application
if __name__ == "__main__":
    enter image description here
    app = QApplication(sys.argv)
    Window = login()
    Window.show()
    sys.exit(app.exec())

script

Answer 1

The way I'd go is that I'd load the .ui files I created into my main file directly (skiping the convertion from .ui to .py part)

See below code for reference:

class Ui(QtWidgets.QMainWindow):
    def __init__(self):
        super(Ui, self).__init__()
        uic.loadUi('get_input.ui', self)
        self.setWindowTitle("Game")
        self.pushButton.pressed.connect(self.save)
        self.show()

    def save(self):
        self.algorithm = self.comboBox.currentText()
        self.close()

Here I have created a ui file called get_input.ui and I load directly onto my code then I interacted with it by getting some input from it. It's much easier this way.