decoder.py 文件源码

def _transpose_batch_time(x):
    """Transpose the batch and time dimensions of a Tensor.

    Retains as much of the static shape information as possible.

    Args:
      x: A tensor of rank 2 or higher.

    Returns:
      x transposed along the first two dimensions.

    Raises:
      ValueError: if `x` is rank 1 or lower.
    """
    x_static_shape = x.get_shape()
    if x_static_shape.ndims is not None and x_static_shape.ndims < 2:
        raise ValueError(
            "Expected input tensor %s to have rank at least 2, but saw shape: %s" %
            (x, x_static_shape))
    x_rank = tf.rank(x)
    x_t = tf.transpose(
        x, tf.concat(
            ([1, 0], tf.range(2, x_rank)), axis=0))
    x_t.set_shape(
        [x_static_shape[1].value, x_static_shape[0].value] + x_static_shape[2:])
    return x_t