main.py

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

class Console(QObject):
    """Output stuff on the console."""

    @Slot(str)
    @Slot('double')
    def output(self, s):
        print(s)

    @Slot(str)
    def outputStr(self, s):
        print(s)

    @Slot('double')
    def outputFloat(self, x):
        print(x)


if __name__ == '__main__':
    app = QGuiApplication(sys.argv)
    view = QQuickView()

    # Instantiate the Python object.
    con = Console()

    # Expose the object to QML.
    context = view.rootContext()
    context.setContextProperty("con", con)

    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)
    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

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

    Text {
        id: helloText
        text: "Hello world!"
        anchors.horizontalCenter: page.horizontalCenter
        y: 30
        font.pointSize: 24; font.bold: true
    }

    Rectangle {
        id: button
        width: 150; height: 40
        color: "darkgray"
        anchors.horizontalCenter: page.horizontalCenter
        y: 120
        MouseArea {
            id: buttonMouseArea
            objectName: "buttonMouseArea"
            anchors.fill: parent
            onClicked: {
                // once the "con" context has been declared,
                // slots can be called like functions
                con.outputFloat(123)
                con.outputStr("foobar")
                con.output(helloText.x)
                con.output(helloText.text)
            }
        }
        Text {
            id: buttonText
            text: "Press me!"
            anchors.horizontalCenter: button.horizontalCenter
            anchors.verticalCenter: button.verticalCenter
            font.pointSize: 16
        }
    }
}