if __name__ == "__main__":     import sys     app = qtwidgets.qapplication(sys.argv)     mainwindow = qtwidgets.qmainwindow()     ui = ui_mainwindow()     ui.setupui(mainwindow)     mainwindow.show()     sys.exit(app.exec_()) 

<?xml version="1.0" encoding="utf-8"?> <ui version="4.0">  <class>mainwindow</class>  <widget class="qmainwindow" name="mainwindow">   <property name="geometry">    <rect>     <x>0</x>     <y>0</y>     <width>1126</width>     <height>694</height>    </rect>   </property>   <property name="windowtitle">    <string>security analysis of the smart home system</string>   </property>   <property name="stylesheet">    <string notr="true"/>   </property> 

def retranslateUi(self, MainWindow):         _translate = QtCore.QCoreApplication.translate         MainWindow.setWindowTitle(_translate("MainWindow", "Security analysis of the Smart Home system"))         self.label.setText(_translate("MainWindow", "Select Smart Home options"))         self.label_2.setText(_translate("MainWindow", "Smart lighting solutions:"))         self.label_3.setText(_translate("MainWindow", "Smart home appliances:"))         self.label_4.setText(_translate("MainWindow", "Control modules:"))         self.label_5.setText(_translate("MainWindow", "Smart CCTV Cameras:"))         self.label_6.setText(_translate("MainWindow", "Smart Garage Door Openers:"))         self.label_7.setText(_translate("MainWindow", "Smart Home Sensors:"))         self.pushButton.setText(_translate("MainWindow", "Analyze"))