code: def _root_path(self):
          
          if self.ROOT_PATH_FOR_DYNACONF is not None:
              return self.ROOT_PATH_FOR_DYNACONF
          elif self._loaded_files:  # called once
              root_path = os.path.dirname(self._loaded_files[0])
              self.set("ROOT_PATH_FOR_DYNACONF", root_path)
              return root_path
docs: ROOT_PATH_FOR_DYNACONF or the path of first loaded file or '.