attention_seq2seq.py 文件源码

def _create_decoder(self, encoder_output, features, _labels):
    attention_class = locate(self.params["attention.class"]) or \
      getattr(decoders.attention, self.params["attention.class"])
    attention_layer = attention_class(
        params=self.params["attention.params"], mode=self.mode)

    # If the input sequence is reversed we also need to reverse
    # the attention scores.
    reverse_scores_lengths = None
    if self.params["source.reverse"]:
      reverse_scores_lengths = features["source_len"]
      if self.use_beam_search:
        reverse_scores_lengths = tf.tile(
            input=reverse_scores_lengths,
            multiples=[self.params["inference.beam_search.beam_width"]])

    return self.decoder_class(
        params=self.params["decoder.params"],
        mode=self.mode,
        vocab_size=self.target_vocab_info.total_size,
        attention_values=encoder_output.attention_values,
        attention_values_length=encoder_output.attention_values_length,
        attention_keys=encoder_output.outputs,
        attention_fn=attention_layer,
        reverse_scores_lengths=reverse_scores_lengths)