text: alien_0 = {"speed": "slow", "x_position": 0}
  alien_1 = {"speed": "medium", "x_position": 0}
  alien_2 = {"speed": "fast", "x_position": 0}
  Aliens = [alien_0, alien_1, alien_2]
  x_increment = 0
  
  for item in Aliens:
      if item['speed'] == 'slow':
          x_increment = 1
          item['x_position'] = x_increment
          print('slow one')
      elif item['speed'] == 'medium':
          x_increment = 2
          item['x_position'] = x_increment
          print('medium one')
      else:
          x_increment = 3
          item['x_position'] = x_increment
          print('fast one')
  
  print(Aliens)
  