In this example the name of my main app class is MyMainApp and the name of my kv file is my.kv
Setting up The Python Script
For each window that we would like to create we need to make an empty class that inherits from the Screen class. If we are going to be working with more than one window then we need to create a class that will manage the navigation between this windows. This class will need to inherit from ScreenManager.
And that is all we need to do from within our python script.
Creating the GUI
For this example I will use a standard login form similar to the ones we've created previously. One window will be the login form and the other will simply have a button that allows us to navigate back to the form.
At the top of our kv file we will define what screens/windows will go inside of our ScreenManager simply by indenting them underneath the ScreenManager class's tag.
We also need to ensure that we add a name attribute for each of our screens/windows. This will be what we use to navigate between them.