def _push_next(self):
        """Assign next batch workload to workers."""
        r = next(self._iter, None)
        if r is None:
            return
        self._key_queue.put((self._sent_idx, r))
        self._sent_idx += 1
def _push_next ( self ) : r = next ( self . _iter , None ) if r is None : return self . _key_queue . put ( ( self . _sent_idx , r ) ) self . _sent_idx += 1
Assign next batch workload to workers.