Resets the iterator to the beginning of the data.

def reset(self):
        """Resets the iterator to the beginning of the data."""
        if self.seq is not None and self.shuffle:
            random.shuffle(self.seq)
        if self.last_batch_handle != 'roll_over' or \
            self._cache_data is None:
            if self.imgrec is not None:
                self.imgrec.reset()
            self.cur = 0
            if self._allow_read is False:
                self._allow_read = True