Python Kivy - Update Property without using kv-language

Question

This is my code:

from kivy.app import App
from kivy.uix.widget import Widget
from kivy.properties import NumericProperty
from kivy.clock import Clock


class MyWidget(Widget):
    score = NumericProperty(0)


class MyWindow(Widget):
    def update(self, dt):
        if self.ids.mywidget.score < 10:
            self.ids.mywidget.score += 1


class MyApp(App):
    def build(self):
        myapp = MyWindow()

        Clock.schedule_interval(myapp.update, .25)
        return myapp


MyApp().run()

kv:

<MyWindow>:
    MyWidget:
        id: mywidget

        Label:
            id: myLabel

            text: '0'
            font_size: 70
            center_x: root.width / 2
            center_y: root.height / 2

What do I have to change in my python file to make the application behave the same as if my kv-file was actually this:

<MyWindow>:
    MyWidget:
        id: mywidget

        Label:
            id: myLabel

            text: str(root.ids.mywidget.score)
            font_size: 70
            center_x: root.width / 2
            center_y: root.height / 2

(I want the label-text to change whenever the score-property changes.)

Thanks in advance

Answer 1

In your MyWidget class, add a method like:

def on_score(self, *args):
    self.parent.ids.myLabel.text = str(self.score)

The above method will be called whenever the score property changes, and will adjust the myLabel accordingly.