code: def select_by_index(self, index):
          
          match = str(index)
          for opt in self.options:
              if opt.get_attribute("index") == match:
                  self._setSelected(opt)
                  return
          raise NoSuchElementException("Could not locate element with index %d" % index)
docs: Select the option at the given index. This is done by examing the "index" attribute of an
             element, and not merely by counting.
  
             :Args:
              - index - The option at this index will be selected
  
             throws NoSuchElementException If there is no option with specified index in SELECT