main.py

import os
import sys
from PySide6.QtCore import QUrl
from PySide6.QtGui import QGuiApplication
from PySide6.QtQuick import QQuickView

def sayThis(s):
    print(s)

if __name__ == '__main__':
    app = QGuiApplication(sys.argv)
    view = QQuickView()
    qmlFile = os.path.join(os.path.dirname(__file__), 'view.qml')
    view.setSource(QUrl.fromLocalFile(os.path.abspath(qmlFile)))
    if view.status() == QQuickView.Error:
        sys.exit(-1)

    root = view.rootObject()
    root.textRotationChanged.connect(sayThis)
    root.buttonClicked.connect(lambda: sayThis("clicked button (QML top-level signal)"))

    view.show()
    res = app.exec_()
    # Deleting the view before it goes out of scope is required to make sure all child QML instances
    # are destroyed in the correct order.
    del view
    sys.exit(res)

view.qml

import QtQuick 2.0

Rectangle {
    id: page

    signal buttonClicked
    signal textRotationChanged(double rot)

    width: 500; height: 200
    color: "lightgray"

    Text {
        id: helloText
        text: "Hello world!"
        y: 30
        x: page.width/2-width/2
        font.pointSize: 24; font.bold: true
        onRotationChanged: textRotationChanged(rotation)

        states: State {
            name: "down"; when: buttonMouseArea.pressed === true
            PropertyChanges {
                target: helloText;
                rotation: 180;
                y: 100;
            }
        }

        transitions: Transition {
            from: ""; to: "down"; reversible: true
            ParallelAnimation {
                NumberAnimation {
                    properties: "y,rotation"
                    duration: 500
                    easing.type: Easing.InOutQuad
                }
            }
        }
    }

    Rectangle {
        id: button
        width: 150; height: 40
        color: "darkgray"
        anchors.horizontalCenter: page.horizontalCenter
        y: 120
        MouseArea {
            id: buttonMouseArea
            objectName: "buttonMouseArea"
            anchors.fill: parent
            onClicked: {
                buttonClicked()
            }
        }
        Text {
            id: buttonText
            text: "Press me!"
            anchors.horizontalCenter: button.horizontalCenter
            anchors.verticalCenter: button.verticalCenter
            font.pointSize: 16
        }
    }
}