This is the kivyexample.py file:

#!/usr/bin/env python
from kivy.app import App
#kivy.require("1.8.0")
from kivy.uix.floatlayout import FloatLayout
 
class MyLayout(FloatLayout):
    pass
 
class KivyExampleApp(App):
    def build(self):
        return MyLayout()
 
if __name__ == "__main__":
    KivyExampleApp().run()

In the code above we derived a class named KivyExampleApp from the Kivy's App class. The Kivy code will automatically search for a file called kivyexample.kv, and it will parse it using the KV language. The name of the file is derived by the class name, making it all lowercase and removing the leftmost App part (if it exists). So this is the kivyexample.kv file:

<MyButton@Button>:
    font_size: 40
    color: 0,1,0,1
    size_hint: 0.3, 0.2

<MyLayout>:
    MyButton:
        text: "Pos 0, 0"
        pos_hint: {'x': 0, 'y': 0}
    MyButton:
        text: "Center x-y"
        pos_hint: {'center_x': 0.5, 'center_y': 0.5}
    MyButton:
        text: "Pos right-top"
        pos_hint: {'right': 0.9, 'top': 0.3}
    MyButton:
        text: "Pos 0.5, 1.0"
        pos_hint: {'right': 0.5, 'top': 1.0}