Create QML component dynamically from Python

app.py

import sys

from PyQt5.QtCore import QUrl, pyqtProperty, pyqtSignal
from PyQt5.QtCore import pyqtSlot
from PyQt5.QtGui import QGuiApplication
from PyQt5.QtQml import QQmlApplicationEngine
from PyQt5.QtQml import qmlRegisterType, QQmlComponent
from PyQt5.QtQuick import QQuickItem


class Widget(QQuickItem):
    def __init__(self, parent=None):
        super().__init__(parent)
        self._name = "Value"
        print("New Widget handler created")

    nameChanged = pyqtSignal()

    @pyqtProperty('QString', notify=nameChanged)
    def name(self):
        return self._name

    @name.setter
    def name(self, name):
        self._name = name
        self.nameChanged.emit()

    @pyqtSlot(str, name="change")
    def change(self, value):
        print("Catched!!!!", value)
        self.name = "Ch-ch-ch-changes! " + value


qmlRegisterType(Widget, 'MyWidgets', 1, 0, 'Widget')

app = QGuiApplication(sys.argv)
engine = QQmlApplicationEngine()
engine.load("app.qml")

# get root (ApplicationWindow casted to QQuickItem)
root = engine.rootObjects()[0].children()[0]

# create component
component = QQmlComponent(engine)
component.loadUrl(QUrl("widget.qml"))
itm = component.create()
itm.setParentItem(root)

# fire and forget
sys.exit(app.exec_())

app.qml

import QtQuick 2.5
import QtQuick.Controls 1.4

ApplicationWindow {
    id: root
    visible: true
    width: 640
    height: 480
}

widget.qml

import QtQuick 2.5
import MyWidgets 1.0

Widget {
	id: self

	Rectangle {
		id: rect
		color: "blue"
		width: 100
		height: 200

        	Text {
            		text: self.name
        	}

		MouseArea {
            		anchors.fill: parent
            		onClicked: {
				parent.color = 'green'
				self.change("We gotcha click!")
			}
        	}
	}
}

@Dinosrules You can use setContextProperty as described in the StackOverflow answer.