Qt for Python (PySide/Shiboken)

file1 = "..." file2 = "..." import sys from PyQt6.QtWidgets import QDialog, QApplication from PyQt6 import uic class Parent(QDialog): def __init__(self, parent=None): super().__init__() uic.loadUi(file1, self) self._parent = parent self.__prepare() def __prepare(self): print('test') class Child(Parent): def __init__(self): super().__init__() self.__prepare() def __prepare(self): self.action_comboBox.currentIndexChanged.connect(self.load_ui) def load_ui(self): print('changed') uic.loadUi(file2, self) if __name__ == '__main__': app = QApplication(sys.argv) window = Child() window.show() sys.exit(app.exec()) Tell please why ui not change, but function called. I did little MEW for you