text: import toga
  
  
  def button_handler(widget):
      print("hello")
  
  
  def build(app):
      box = toga.Box()
  
      button = toga.Button('Hello world', on_press=button_handler)
      button.style.padding = 50
      button.style.flex = 1
      box.add(button)
  
      return box
  
  
  def main():
      return toga.App('First App', 'org.pybee.helloworld', startup=build)
  
  
  if __name__ == '__main__':
      main().main_loop()
  