# tf.contrib.feature_column.sequence_input_layer

tf.contrib.feature_column.sequence_input_layer(
features,
feature_columns,
weight_collections=None,
trainable=True
)


"Builds input layer for sequence input.

All feature_columns must be sequence dense columns with the same sequence_length. The output of this method can be fed into sequence networks, such as RNN.

The output of this method is a 3D Tensor of shape [batch_size, T, D]. T is the maximum sequence length for this batch, which could differ from batch to batch.

If multiple feature_columns are given with Di num_elements each, their outputs are concatenated. So, the final Tensor has shape [batch_size, T, D0 + D1 + ... + Dn].

Example:

rating = sequence_numeric_column('rating')
watches = sequence_categorical_column_with_identity(
'watches', num_buckets=1000)
watches_embedding = embedding_column(watches, dimension=10)
columns = [rating, watches]

features = tf.parse_example(..., features=make_parse_example_spec(columns))
input_layer, sequence_length = sequence_input_layer(features, columns)

rnn_cell = tf.nn.rnn_cell.BasicRNNCell(hidden_size)
outputs, state = tf.nn.dynamic_rnn(
rnn_cell, inputs=input_layer, sequence_length=sequence_length)


#### Args:

• features: A dict mapping keys to tensors.
• feature_columns: An iterable of dense sequence columns. Valid columns are
• embedding_column that wraps a sequence_categorical_column_with_*
• sequence_numeric_column.
• weight_collections: A list of collection names to which the Variable will be added. Note that variables will also be added to collections tf.GraphKeys.GLOBAL_VARIABLES and ops.GraphKeys.MODEL_VARIABLES.
• trainable: If True also add the variable to the graph collection GraphKeys.TRAINABLE_VARIABLES.

#### Returns:

An (input_layer, sequence_length) tuple where: - input_layer: A float Tensor of shape [batch_size, T, D]. T is the maximum sequence length for this batch, which could differ from batch to batch. D is the sum of num_elements for all feature_columns. - sequence_length: An int Tensor of shape [batch_size]. The sequence length for each example.

#### Raises:

• ValueError: If any of the feature_columns is the wrong type.