How do I switch between 2 screens with Kivy written in pure python?

Question

What I'm trying to do is create two screens, each with two buttons. One button switches to the other screen, and the other button just executes some code (just a print statement right now). I can't quite figure out how I'm supposed to be tying a name to a screen, because when I try and switch screens with my button I get the error

kivy.uix.screenmanager.ScreenManagerException: No Screen with name "screen2"

I tried printing out the name of the screens I created, and I just get

['', '']

So I assume that the two screens I made were created, but my attempt to name them failed.

Here's my full code:

#PYTHON 3.4.4
#KIVY 1.9.1


from kivy.app import App
from kivy.uix.widget import Widget
from kivy.uix.button import Button
from kivy.uix.floatlayout import FloatLayout
from kivy.uix.screenmanager import ScreenManager, Screen


class ScreenOne(Screen):

    def __init__(self, **kwargs):
        super().__init__()

        btn1 = Button(
            text='change screen',
            size_hint=(.5, .25),
            pos_hint={'left':0, 'top':1}
            )
        btn1.bind(on_press=self.changer)
        self.add_widget(btn1)

        other_btn1 = Button(
            text='test button',
            size_hint=(.5, .25),
            pos_hint={'right':1, 'bottom':0}
            )
        other_btn1.bind(on_press=self.test)
        self.add_widget(other_btn1)


    def changer(self,*args):

        self.manager.current = 'screen2'

    def test(self,instance):
        print('This is a test')



class ScreenTwo(Screen):

    def __init__(self, **kwargs):
        super().__init__()

        btn2 = Button(
            text='change screen',
            size_hint=(.5, .25),
            pos_hint={'left':0, 'top':1}
            )
        btn2.bind(on_press=self.changer)
        self.add_widget(btn2)


        other_btn2 = Button(
            text='test button 2',
            size_hint=(.5, .25),
            pos_hint={'right':1, 'bottom':0}
            )
        other_btn2.bind(on_press=self.test)
        self.add_widget(other_btn2)


    def changer(self,*args):
        self.manager.current = 'screen1'

    def test(self,instance):
        print('This is another test')




class TestApp(App):

    def build(self):
        sm = ScreenManager()
        sc1 = ScreenOne(name='screen1')
        sc2 = ScreenTwo(name='screen2')
        sm.add_widget(sc1)
        sm.add_widget(sc2)
        print (sm.screen_names)
        return sm


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

Answer 1

If you want your "kid" to act as a "parent" give him a chance to listen to the same "kwargs".

Feed super(). init () with **kwargs and it will work.