title: How to delete a widget in python kivy
body: <p>I wanted to remove the 'bl' widget by clicking the 'horny mode' button, but it is not initially on the screen. How can I make the widget be removing by clicking on the button?</p>
  <pre><code>from kivy.app import App
  from kivy.uix.boxlayout import BoxLayout
  from kivy.uix.anchorlayout import AnchorLayout
  from kivy.uix.floatlayout import FloatLayout
  from kivy.lang import Builder
  from kivy.uix.button import Button
  from kivy.config import Config
  from kivy.core.window import Window
  from kivy.uix.image import Image
  from kivy.uix.widget import Widget
  
  class ScraperApp(App, FloatLayout):
      def PhotGif(self):
          wentil = Image(source='img.gif', size_hint = (.5, .5), anim_loop = 99999)
          photo = AnchorLayout(anchor_x='center', anchor_y='top', padding = [0, 75, 0, 0])
          photo.add_widget(wentil)
          return photo
  
      def build(self):
          
          bl = BoxLayout(orientation='horizontal', padding = [50, 100, 50, 150], spacing = 5)
          bl.add_widget( Button(text = '1', on_press = self.first, font_size = 20, size_hint = (.3, .1)))
          bl.add_widget( Button(text = '2', on_press = self.second, font_size = 20, size_hint = (.3, .1)))
          #bl.add_widget( Button(text = 'Wallpaper mode', on_press = self.wallpaper, font_size = 20, size_hint = (.3, .1)))
          wid = FloatLayout()
          wid.add_widget(ScraperApp().PhotGif())
          wid.add_widget(bl)
          return wid
  
      def first(self, instance):
          print('Horny mode')
          instance.text = 'кнопка нажата'
          ScraperApp().build().remove_widget(bl)
          stop()
  
      def stop():
          ScraperApp().build().remove_widget(bl)
  
      def second(self, instance):
          print('Soft mode')
          instance.text = 'кнопка нажата'
  
  if __name__ == '__main__':
      ScraperApp().run()
  </code></pre>
  <p>Can you help me make so that when you click on any button, the widget with the buttons removed?</p>