动态创建的kivy小部件上的按钮操作

from kivy.app import App
from kivy.uix.button import Button
from kivy.uix.boxlayout import BoxLayout

class MyWidget(BoxLayout):
    def button_clicked(self, button):
        print("Button", button.text, "is clicked.")

class MyApp(App):
    def build(self):
        widget = MyWidget()
        for i in range(3):
            button = Button(text="Button {}".format(i+1))
            button.bind(on_release=widget.button_clicked)
            widget.add_widget(button)
        return widget

if __name__ == '__main__':
    MyApp().run()