Qt Fading animation : Py vs C++

fading_example.cpp

void MainInterface::ShowPathToCurr() {
	TreeNodeButton* NodeButton = qobject_cast<TreeNodeButton*>(sender());
	QPropertyAnimation *a;
	int i = 1;
	for (Node* curr = NodeButton->get_localref(); !curr->activated; curr=curr->prev,++i){
		QGraphicsOpacityEffect *eff = new QGraphicsOpacityEffect(this);
		a= new QPropertyAnimation(eff, "opacity");
		curr->Widgetptr->setGraphicsEffect(eff);
		curr->Widgetptr->setGraphicsEffect(eff);
		a->setDuration(1000+i*500);
		a->setStartValue(1);
		a->setKeyValueAt(0.5, 0);
		a->setEndValue(1);
		connect(a, SIGNAL(finished()), curr->Widgetptr, SLOT(fadeFinish()));
		a->setEasingCurve(QEasingCurve::OutBack);
		a->start(QAbstractAnimation::DeleteWhenStopped);
	}
}

fading_example.py

def fade(self):
    self.ui.hint.setText("File has been save successfully.")
    self.ui.hint.setStyleSheet("color:lawngreen;")
    self.effect= QGraphicsOpacityEffect(self.ui.hint)
    self.animation = QtCore.QPropertyAnimation(self.effect, b"opacity")
    self.ui.hint.setGraphicsEffect(self.effect)
    self.animation.setStartValue(0)
    self.animation.setKeyValueAt(0.5,1)
    self.animation.setEndValue(0)
    self.animation.setDuration(2000)
    self.animation.start(QtCore.QAbstractAnimation.DeleteWhenStopped)