code: def location_for(self, path):
          
          path = path.split('.')
          node = self
          while node._parent:
              node = node._parent
          location = node.location
          for name in path:
              tree = node._tree.get(name, None)
              if tree is None or type(tree) is float:
                  return location
              location = tree.location
          return location
docs: Return the location code for a path.