code: def clear(self):
          
          for root, dirs, files in os.walk(self._root_dir, topdown=False):
              for file in files:
                  os.unlink(os.path.join(root, file))
              os.rmdir(root)
          # Get the root dir back and re-initialise to start again
          root_dir = os.path.abspath(
              os.path.join(self._root_dir, os.pardir))
          self.__init__(root_dir)
docs: Clears all data from the data store permanently