Kivy - Black screen -

Question

I'm working with Kivy in Ubuntu. When I write the widgets on the.kv file, it's all successful, but when I try the code syntax, it just appears a blank screen and I have no idea what to do. Someone please help.

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

class BoxLayoutExample(BoxLayout):
    def __int__(self, **kwargs):
        super().__init__(**kwargs) 
        self.orientation = "vertical"
        b1 = Button(text="A")
        b2 = Button(text="B")
        b3 = Button(text="C")
        self.add_widget(b1)
        self.add_widget(b2)
        self.add_widget(b3)
    

class TheLabApp(App):
    pass


TheLabApp().run()

Answer 1

This line was changed:

        super(BoxLayoutExample, self).__init__(**kwargs)

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

class BoxLayoutExample(BoxLayout):
    def __init__(self, **kwargs):
        super(BoxLayoutExample, self).__init__(**kwargs)
        self.orientation = "vertical"
        b1 = Button(text="A")
        b2 = Button(text="B")
        b3 = Button(text="C")
        self.add_widget(b1)
        self.add_widget(b2)
        self.add_widget(b3)


class TheLabApp(App):
    def build(self):
        return BoxLayoutExample()


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