(self, key)
Open key for reading. Default implementation simply raises a
        :py:exc:`~exceptions.NotImplementedError`.

        :param key: Key to open
Open key for reading. Default implementation simply raises a
        :py:exc:`~exceptions.NotImplementedError`.
Open key for reading . Default implementation simply raises a : py : exc : ~exceptions . NotImplementedError .
def _open(self, key):
        """Open key for reading. Default implementation simply raises a
        :py:exc:`~exceptions.NotImplementedError`.

        :param key: Key to open
        """
        raise NotImplementedError
def _open ( self , key ) : raise NotImplementedError