def __init__(self, **kwargs):
    super().__init__(**kwargs)
    self.txt = Label(text='')
    self.btn = Button(text='rebut')
    self.btn.on_press = self.back
    self.btn.background_color = btn_color
    main_bl = BoxLayout(orientation='vertical')
    bl1 = BoxLayout(orientation='vertical', size_hint=(1, 0.9))
    bl2 = BoxLayout(size_hint=(1, 0.1))
    bl1.add_widget(self.txt)
    bl2.add_widget(self.btn)
    main_bl.add_widget(bl1)
    main_bl.add_widget(bl2)
    self.add_widget(main_bl)
    self.on_enter = self.index_ruffier
def __init__(self, **kwargs):
    super().__init__(**kwargs)
    self.txt = Label(text=)
    self.btn = Button(text='rebut')
    self.btn.on_press = self.back
    self.btn.background_color = btn_color
    main_bl = BoxLayout(orientation='vertical')
    bl1 = BoxLayout(orientation='vertical', size_hint=(1, 0.9))
    bl2 = BoxLayout(size_hint=(1, 0.1))
    bl1.add_widget(self.txt)
    bl2.add_widget(self.btn)
    main_bl.add_widget(bl1)
    main_bl.add_widget(bl2)
    self.add_widget(main_bl)
    self.on_enter = self.index_ruffier