import sys from PyQt5 import QtWidgets from ui.CalibracaoPressaoW import Ui_CalibracaoPressaoW from threads.MainThread import MainThread class Ui_MainWindow(object): def __init__(self): self.app = QtWidgets.QApplication(sys.argv) self.dialog = QtWidgets.QMainWindow() self.ui = Ui_CalibracaoPressaoW() self.ui.setupUi(self.dialog) main_thread = MainThread(self.ui) main_thread.finished.connect(self.app.exit) main_thread.start() self.dialog.showMaximized()