Hello QML

app.py

import sys
import random
from PyQt5 import QtCore, QtGui, QtQuick


class MyStupidModel(QtCore.QObject):

    @QtCore.pyqtSlot(result=str)
    def greet(self):
        friends = ("Rob", "Fabrice", "Eoin", "Baz", "Stefano",
                   "Cesar", "JP", "Matt", "Frieder", "everybody!")
        return "Hello {}".format(random.choice(friends))


def main():
    app = QtGui.QGuiApplication(sys.argv)

    model = MyStupidModel()

    view = QtQuick.QQuickView()
    view.setSource(QtCore.QUrl("Hello.qml"))
    view.rootContext().setContextProperty("pymodel", model)
    view.show()

    sys.exit(app.exec_())

if __name__ == "__main__":
    main()

Cell.qml

import QtQuick 2.5

Item {
    id: container
    property alias cellColor: rectangle.color
    signal clicked(color cellColor)

    width: 40; height: 25

    Rectangle {
        id: rectangle
        anchors.fill: parent
    }

    MouseArea {
        anchors.fill: parent
        onClicked: container.clicked(container.cellColor)
    }
}

Hello.qml

import QtQuick 2.5


Rectangle {
    id: container
    color: "slategray"
    width: 300; height: 200

    Behavior on color {
        ColorAnimation {
            duration: 1000
        }
    }

    Text {
        id: helloText
        color: "white"
        text: "Hello QML"
        font.pointSize: 24; font.bold: true
        anchors.centerIn: parent

        MouseArea {
            anchors.fill: parent
            onClicked: helloText.text = pymodel.greet()
        }
    }

    Grid {
        rows: 2; columns: 2; spacing: 3

        Cell { cellColor: "green"; onClicked: container.color = cellColor }
        Cell { cellColor: "blue"; onClicked: container.color = cellColor }
        Cell { cellColor: "steelblue"; onClicked: container.color = cellColor }
        Cell { cellColor: "black"; onClicked: container.color = cellColor }
    }
}