code: def get(scope, source, index):
      
      try:
          index = int(index[0])
      except IndexError:
          raise ValueError('index variable is required')
      except ValueError:
          raise ValueError('index is not an integer')
      try:
          return [source[index]]
      except IndexError:
          raise ValueError('no such item in the list')
docs: Returns a copy of the list item with the given index.
      It is an error if an item with teh given index does not exist.
  
      :type  source: string
      :param source: A list of strings.
      :type  index: string
      :param index: A list of strings.
      :rtype:  string
      :return: The cleaned up list of strings.