code: def _hash(self, hash_name):
          
          m = hashlib.new(hash_name)
          for chunk in self.chunks(8192, mode="rb"):
              m.update(chunk)
          return m
docs: Returns a hash object for the file at the current path.
  
          `hash_name` should be a hash algo name (such as ``'md5'``
          or ``'sha1'``) that's available in the :mod:`hashlib` module.