self.equals.setText(_translate("MainWindow", "=")) class MyWin(QtWidgets.QMainWindow): def __init__(self, parent=None): QtWidgets.QtWidget.__init__(self, parent) self.ui = Ui_MainWindow() self.ui.setupUi(self) self.ui.solutio_clc.clicked.connect(self.result) def result(self): try: n1 = self.ui.number.text() n2 = int(self.ui.degree.text()) s = int(n1, n2) self.ui.lblSum.setText(str(s)) except: msg = QtWidgets.QMessageBox() msg.setWindowTititle("Input error") msg.setText("Input corret data!") msg.SetIcon(msg.Warning) msg.exec() if __name__ == "main": app = QtWidgets.QApplacation(sys.argv) myapp = MyWin() myapp.show() sys.exit(app.exec_())