from kivy.app import App
from kivy.lang import Builder
from kivy.factory import Factory
from kivy.uix.label import Label
from kivy.uix.button import Button
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.screenmanager import Screen
 
letters = ["txt 1","txt 2","txt 3","txt 5", "txt 6"] 
 
class MButton(Button):
    pass

class MyW(BoxLayout):
	def __init__(self, **kwargs):
		super(MyW, self).__init__(**kwargs)
		for l in letters:
		    s = Screen(name=l)
		    s.add_widget(Label(text=l))
		    self.ids.sm.add_widget(s)
		    self.ids.buttons.add_widget(MButton(text=l))

class e4App(App):

    def build(self):
    	return MyW() 
 
if __name__ == '__main__':
    e4App().run()