def METHOD_NAME(self):
    for i in range(self.tab_widget_1.count()):
        self.tab_widget_1.widget(i).setSizePolicy(QtWidgets.QSizePolicy.Ignored, QtWidgets.QSizePolicy.Ignored)
    self.tab_widget_1.currentWidget().setSizePolicy(QtWidgets.QSizePolicy.Preferred,
                                                    QtWidgets.QSizePolicy.Preferred)
    self.tab_widget_1.currentWidget().resize(self.tab_widget_1.currentWidget().minimumSizeHint())
    self.tab_widget_1.currentWidget().adjustSize()