title: Problem with Python not opening up files in the correct order
body: <p>I'm using Python 3.9 and Kivy</p>
  <pre><code> from kivy.config import Config 
  Config.set('graphics', 'resizable', False)
  Config.set('graphics', 'width',  800)
  Config.set('graphics', 'height', 600)
  Config.set('input', 'mouse', 'mouse,multitouch_on_demand')
  
  import kivy
  from kivy.app import App
  from kivy.uix.label import Label
  from kivy.uix.gridlayout import GridLayout
  from kivy.uix.textinput import TextInput
  from kivy.uix.button import Button
  from kivy.uix.widget import Widget
  from kivy.core.window import Window
  from kivy.properties import ObjectProperty
  from kivy.lang import Builder
  import subprocess
  
  
  
  
  
  presentation = Builder.load_file('UI_1.kv')
  
  #Calling files to open 
  #Always use popen 
  
  class presentation(Widget):
      maths = ObjectProperty(None)
      physics = ObjectProperty(None)
  
  
      def btn_touch_up(maths):        
          from subprocess import Popen, PIPE
          subprocess.Popen(['python',  'UI_MATH.py'])
          exit()
  
  
  
      def btn_touch_up(physics):        
          from subprocess import Popen, PIPE
          subprocess.Popen(['python',  'UI_PHYSICS.py'])
          exit()
  
  
  
  
          
  
  class MyApp(App): 
      def build(self):
          return presentation()
  
  
  
  
  
  Window.clearcolor = (1, 1, 1, 1)
  
  
  
  
  if __name__ == &quot;__main__&quot;:
      MyApp().run()
  </code></pre>
  <p>So that's the code I wrote. The problem is that when I run the app and click the first box (labeled maths), the code for the 2 box opens up (physics). When I clock the second box (Physics) it runs the correct code. Can someone point out my error so I can correct it? I'm fairly new so my code might seem like a mess...</p>
  <p>Here is the code from the kivy (.kv) file:</p>
  <pre><code>&lt;presentation&gt;
  
      maths : maths
      physics : physics
      extra : extra
  
  
      canvas:
          Color:
              rgb:0,0,0
          Rectangle:
              pos:8,498
              size:790,50
          
          Rectangle:
              pos:8,398
              size:790,50
          
          Rectangle:
              pos:8,298
              size:790,50
  
      GridLayout:
  
      
  
          cols:1
          size: root.width -10, root.height -550
          pos: 5, 500
  
  
          GridLayout:
              cols:1      
      
  
              Button:
                  id: maths
                  text:&quot;1.Maths&quot;
                  on_press: root.btn_touch_up()
                  
  
  
  
      
      GridLayout:
          cols:1
          size: root.width -10, root.height -550
          pos: 5, 400
  
  
          GridLayout:
              cols:1          
  
              Button:
                  id: physics
                  text:&quot;2.Physics&quot;
                  on_press: root.btn_touch_up()
  
  
  
      GridLayout:
          cols:1
          size: root.width -10, root.height -550
          pos: 5, 300
  
  
          GridLayout:
              cols:1
  
  
              
  
              Button:
                  id: extra
                  text:&quot;3.Extra&quot;
                  on_press: root.btn_touch_up()
              
  </code></pre>
  <p>Thank you, and again, i'm really new and self taught so if there is something obviously wrong that I shouldn't do please point it out.</p>