Uses a Module to construct dense representations from sparse text features.

The input to this feature column is a batch of multiple strings with arbitrary size, assuming the input is a SparseTensor.

This type of feature column is typically suited for modules that operate on pre-tokenized text to produce token level embeddings which are combined with the combiner into a text embedding. The combiner always treats the tokens as a bag of words rather than a sequence.

The output (i.e., transformed input layer) is a DenseTensor, with shape [batch_size, num_embedding_dim].

For Example:

  comment = hub.sparse_text_embedding_column("comment", "/tmp/text_module")
  feature_columns = [comment, ...]
  features = {
    "comment": tf.SparseTensor(indices=[[0, 0], [1, 2]],
                               values=['sparse', 'embedding'],
                               dense_shape=[3, 4]),
  estimator = tf.estimator.DNNClassifier(hidden_units, feature_columns)

key A string or _FeatureColumn identifying the text feature.
module_spec A string handle or a _ModuleSpec identifying the module.
combiner a string specifying reducing op for embeddings in the same Example. Currently, 'mean', 'sqrtn', 'sum' are supported. Using combiner=None is undefined.
default_value default value for Examples where the text feature is empty. Note, it's recommended to have default_value consistent OOV tokens, in case there was special handling of OOV in the text module. If None, the text feature is assumed be non-empty for each Example.
trainable Whether or not the Module is trainable. False by default, meaning the pre-trained weights are frozen. This is different from the ordinary tf.feature_column.embedding_column(), but that one is intended for training from scratch.

_DenseColumn that converts from text input.

ValueError if module_spec is not suitable for use in this feature column.
ValueError if combiner not in ('mean', 'sqrtn', 'sum').