Kv Design LanguageΒΆ
Designing with the kv language.
Kivy provides a design language specifically geared towards ease of GUI Design, which makes it easier to separate interface design and logic from internal design and logic. For example:

In the above code :
<LoginScreen>: # every class in your app can be represented by a rule like this in the kv file
GridLayout: # this is how you add your widget/layout to the parent (note the indentation).
rows: 2 # this how you set each property of your widget/layout
That’s it, that’s how simple it is to design your GUI in the kv language. To get a more in-depth understanding look at Introduction to the Kivy Language