text: # Copyright 2017 The TensorFlow Authors. All Rights Reserved.
  #
  # Licensed under the Apache License, Version 2.0 (the "License");
  # you may not use this file except in compliance with the License.
  # You may obtain a copy of the License at
  #
  #     http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  # ==============================================================================
  """This API defines FeatureColumn abstraction.
  
  FeatureColumns provide a high level abstraction for ingesting and representing
  features. FeatureColumns are also the primary way of encoding features for
  canned `tf.estimator.Estimator`s.
  
  When using FeatureColumns with `Estimators`, the type of feature column you
  should choose depends on (1) the feature type and (2) the model type.
  
  1. Feature type:
  
    * Continuous features can be represented by `numeric_column`.
    * Categorical features can be represented by any `categorical_column_with_*`
    column:
      - `categorical_column_with_vocabulary_list`
      - `categorical_column_with_vocabulary_file`
      - `categorical_column_with_hash_bucket`
      - `categorical_column_with_identity`
      - `weighted_categorical_column`
  
  2. Model type:
  
    * Deep neural network models (`DNNClassifier`, `DNNRegressor`).
  
      Continuous features can be directly fed into deep neural network models.
  
        age_column = numeric_column("age")
  
      To feed sparse features into DNN models, wrap the column with
      `embedding_column` or `indicator_column`. `indicator_column` is recommended
      for features with only a few possible values. For features with many
      possible values, to reduce the size of your model, `embedding_column` is
      recommended.
  
        embedded_dept_column = embedding_column(
            categorical_column_with_vocabulary_list(
                "department", ["math", "philosophy", ...]), dimension=10)
  
    * Wide (aka linear) models (`LinearClassifier`, `LinearRegressor`).
  
      Sparse features can be fed directly into linear models. They behave like an
      indicator column but with an efficient implementation.
  
        dept_column = categorical_column_with_vocabulary_list("department",
            ["math", "philosophy", "english"])
  
      It is recommended that continuous features be bucketized before being
      fed into linear models.
  
        bucketized_age_column = bucketized_column(
            source_column=age_column,
            boundaries=[18, 25, 30, 35, 40, 45, 50, 55, 60, 65])
  
      Sparse features can be crossed (also known as conjuncted or combined) in
      order to form non-linearities, and then fed into linear models.
  
        cross_dept_age_column = crossed_column(
            columns=["department", bucketized_age_column],
            hash_bucket_size=1000)
  
  Example of building canned `Estimator`s using FeatureColumns:
  
    ```python
    # Define features and transformations
    deep_feature_columns = [age_column, embedded_dept_column]
    wide_feature_columns = [dept_column, bucketized_age_column,
        cross_dept_age_column]
  
    # Build deep model
    estimator = DNNClassifier(
        feature_columns=deep_feature_columns,
        hidden_units=[500, 250, 50])
    estimator.train(...)
  
    # Or build a wide model
    estimator = LinearClassifier(
        feature_columns=wide_feature_columns)
    estimator.train(...)
  
    # Or build a wide and deep model!
    estimator = DNNLinearCombinedClassifier(
        linear_feature_columns=wide_feature_columns,
        dnn_feature_columns=deep_feature_columns,
        dnn_hidden_units=[500, 250, 50])
    estimator.train(...)
    ```
  
  
  FeatureColumns can also be transformed into a generic input layer for
  custom models using `input_layer`.
  
  Example of building model using FeatureColumns, this can be used in a
  `model_fn` which is given to the {tf.estimator.Estimator}:
  
    ```python
    # Building model via layers
  
    deep_feature_columns = [age_column, embedded_dept_column]
    columns_to_tensor = parse_feature_columns_from_examples(
        serialized=my_data,
        feature_columns=deep_feature_columns)
    first_layer = input_layer(
        features=columns_to_tensor,
        feature_columns=deep_feature_columns)
    second_layer = fully_connected(first_layer, ...)
    ```
  
  NOTE: Functions prefixed with "_" indicate experimental or private parts of
  the API subject to change, and should not be relied upon!
  """
  
  from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  
  import abc
  import collections
  import math
  
  import numpy as np
  import six
  
  
  from tensorflow.python.eager import context
  from tensorflow.python.feature_column import feature_column as fc_old
  from tensorflow.python.feature_column import utils as fc_utils
  from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import ops
  from tensorflow.python.framework import sparse_tensor as sparse_tensor_lib
  from tensorflow.python.framework import tensor_shape
  # TODO(b/118385027): Dependency on keras can be problematic if Keras moves out
  # of the main repo.
  from tensorflow.python.keras import initializers
  from tensorflow.python.keras.utils import generic_utils
  from tensorflow.python.keras.engine import training
  from tensorflow.python.keras.engine.base_layer import Layer
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import check_ops
  from tensorflow.python.ops import control_flow_ops
  from tensorflow.python.ops import embedding_ops
  from tensorflow.python.ops import init_ops
  from tensorflow.python.ops import lookup_ops
  from tensorflow.python.ops import math_ops
  from tensorflow.python.ops import nn_ops
  from tensorflow.python.ops import parsing_ops
  from tensorflow.python.ops import sparse_ops
  from tensorflow.python.ops import string_ops
  from tensorflow.python.ops import variable_scope
  from tensorflow.python.ops import variables
  from tensorflow.python.platform import gfile
  from tensorflow.python.platform import tf_logging as logging
  from tensorflow.python.training import checkpoint_utils
  from tensorflow.python.training.tracking import tracking
  from tensorflow.python.util import deprecation
  from tensorflow.python.util import nest
  from tensorflow.python.util.tf_export import tf_export
  from tensorflow.python.util.compat import collections_abc
  
  
  _FEATURE_COLUMN_DEPRECATION_DATE = None
  _FEATURE_COLUMN_DEPRECATION = ('The old _FeatureColumn APIs are being '
                                 'deprecated. Please use the new FeatureColumn '
                                 'APIs instead.')
  
  
  class StateManager(object):
    """Manages the state associated with FeatureColumns.
  
    Some `FeatureColumn`s create variables or resources to assist their
    computation. The `StateManager` is responsible for creating and storing these
    objects since `FeatureColumn`s are supposed to be stateless configuration
    only.
    """
  
    def create_variable(self,
                        feature_column,
                        name,
                        shape,
                        dtype=None,
                        trainable=True,
                        use_resource=True,
                        initializer=None):
      """Creates a new variable.
  
      Args:
        feature_column: A `FeatureColumn` object this variable corresponds to.
        name: variable name.
        shape: variable shape.
        dtype: The type of the variable. Defaults to `self.dtype` or `float32`.
        trainable: Whether this variable is trainable or not.
        use_resource: If true, we use resource variables. Otherwise we use
          RefVariable.
        initializer: initializer instance (callable).
  
      Returns:
        The created variable.
      """
      del feature_column, name, shape, dtype, trainable, use_resource, initializer
      raise NotImplementedError('StateManager.create_variable')
  
    def add_variable(self, feature_column, var):
      """Adds an existing variable to the state.
  
      Args:
        feature_column: A `FeatureColumn` object to associate this variable with.
        var: The variable.
      """
      del feature_column, var
      raise NotImplementedError('StateManager.add_variable')
  
    def get_variable(self, feature_column, name):
      """Returns an existing variable.
  
      Args:
        feature_column: A `FeatureColumn` object this variable corresponds to.
        name: variable name.
      """
      del feature_column, name
      raise NotImplementedError('StateManager.get_var')
  
    def add_resource(self, feature_column, name, resource):
      """Creates a new resource.
  
      Resources can be things such as tables etc.
  
      Args:
        feature_column: A `FeatureColumn` object this resource corresponds to.
        name: Name of the resource.
        resource: The resource.
  
      Returns:
        The created resource.
      """
      del feature_column, name, resource
      raise NotImplementedError('StateManager.add_resource')
  
    def get_resource(self, feature_column, name):
      """Returns an already created resource.
  
      Resources can be things such as tables etc.
  
      Args:
        feature_column: A `FeatureColumn` object this variable corresponds to.
        name: Name of the resource.
      """
      del feature_column, name
      raise NotImplementedError('StateManager.get_resource')
  
  
  class _StateManagerImpl(StateManager):
    """Manages the state of DenseFeatures and LinearLayer."""
  
    def __init__(self, layer, trainable):
      """Creates an _StateManagerImpl object.
  
      Args:
        layer: The input layer this state manager is associated with.
        trainable: Whether by default, variables created are trainable or not.
      """
      self._trainable = trainable
      self._layer = layer
      if self._layer is not None:
        self._layer._maybe_create_attribute('_resources', [])  # pylint: disable=protected-access
      self._cols_to_vars_map = collections.defaultdict(lambda: {})
      # TODO(vbardiovsky): Make sure the resources are tracked by moving them to
      # the layer (inheriting from AutoTrackable), e.g.:
      # self._layer._resources_map = data_structures.Mapping()
      self._cols_to_resources_map = collections.defaultdict(lambda: {})
  
    def create_variable(self,
                        feature_column,
                        name,
                        shape,
                        dtype=None,
                        trainable=True,
                        use_resource=True,
                        initializer=None):
      if name in self._cols_to_vars_map[feature_column]:
        raise ValueError('Variable already exists.')
  
      var = self._layer.add_variable(
          name=name,
          shape=shape,
          dtype=dtype,
          initializer=initializer,
          trainable=self._trainable and trainable,
          use_resource=use_resource,
          # TODO(rohanj): Get rid of this hack once we have a mechanism for
          # specifying a default partitioner for an entire layer. In that case,
          # the default getter for Layers should work.
          getter=variable_scope.get_variable)
      self._cols_to_vars_map[feature_column][name] = var
      return var
  
    def get_variable(self, feature_column, name):
      if name in self._cols_to_vars_map[feature_column]:
        return self._cols_to_vars_map[feature_column][name]
      raise ValueError('Variable does not exist.')
  
    def add_resource(self, feature_column, name, resource):
      self._cols_to_resources_map[feature_column][name] = resource
      if self._layer is not None:
        self._layer._resources.append(resource)  # pylint: disable=protected-access
  
    def get_resource(self, feature_column, name):
      if name in self._cols_to_resources_map[feature_column]:
        return self._cols_to_resources_map[feature_column][name]
      raise ValueError('Resource does not exist.')
  
  
  class _StateManagerImplV2(_StateManagerImpl):
    """Manages the state of DenseFeatures."""
  
    def create_variable(self,
                        feature_column,
                        name,
                        shape,
                        dtype=None,
                        trainable=True,
                        use_resource=True,
                        initializer=None):
      if name in self._cols_to_vars_map[feature_column]:
        raise ValueError('Variable already exists.')
  
      var = self._layer.add_variable(
          name=name,
          shape=shape,
          dtype=dtype,
          initializer=initializer,
          trainable=self._trainable and trainable,
          use_resource=use_resource)
      self._cols_to_vars_map[feature_column][name] = var
      return var
  
  
  class _BaseFeaturesLayer(Layer):
    """Base class for DenseFeatures and SequenceFeatures.
  
    Defines common methods and helpers.
  
    Args:
      feature_columns: An iterable containing the FeatureColumns to use as
        inputs to your model.
      expected_column_type: Expected class for provided feature columns.
      trainable:  Boolean, whether the layer's variables will be updated via
        gradient descent during training.
      name: Name to give to the DenseFeatures.
      **kwargs: Keyword arguments to construct a layer.
  
    Raises:
      ValueError: if an item in `feature_columns` doesn't match
        `expected_column_type`.
    """
    def __init__(self, feature_columns, expected_column_type, trainable, name,
                 **kwargs):
      super(_BaseFeaturesLayer, self).__init__(
          name=name, trainable=trainable, **kwargs)
      self._feature_columns = _normalize_feature_columns(feature_columns)
      self._state_manager = _StateManagerImpl(self, self.trainable)
      for column in self._feature_columns:
        if not isinstance(column, expected_column_type):
          raise ValueError(
              'Items of feature_columns must be a {}. '
              'You can wrap a categorical column with an '
              'embedding_column or indicator_column. Given: {}'.format(
                  expected_column_type, column))
  
    def build(self, _):
      for column in self._feature_columns:
        with variable_scope._pure_variable_scope(self.name):  # pylint: disable=protected-access
          with variable_scope._pure_variable_scope(column.name):  # pylint: disable=protected-access
            column.create_state(self._state_manager)
      super(_BaseFeaturesLayer, self).build(None)
  
    def _output_shape(self, input_shape, num_elements):
      """Computes expected output shape of the layer or a column's dense tensor.
  
      Args:
        input_shape: Tensor or array with batch shape.
        num_elements: Size of the last dimension of the output.
  
      Returns:
        Tuple with output shape.
      """
      raise NotImplementedError('Calling an abstract method.')
  
    def compute_output_shape(self, input_shape):
      total_elements = 0
      for column in self._feature_columns:
        total_elements += column.variable_shape.num_elements()
      return self._target_shape(input_shape, total_elements)
  
    def _process_dense_tensor(self, column, tensor):
      """Reshapes the dense tensor output of a column based on expected shape.
  
      Args:
        column: A DenseColumn or SequenceDenseColumn object.
        tensor: A dense tensor obtained from the same column.
  
      Returns:
        Reshaped dense tensor."""
      num_elements = column.variable_shape.num_elements()
      target_shape = self._target_shape(array_ops.shape(tensor), num_elements)
      return array_ops.reshape(tensor, shape=target_shape)
  
    def _verify_and_concat_tensors(self, output_tensors):
      """Verifies and concatenates the dense output of several columns."""
      _verify_static_batch_size_equality(output_tensors, self._feature_columns)
      return array_ops.concat(output_tensors, -1)
  
    def get_config(self):
      # Import here to avoid circular imports.
      from tensorflow.python.feature_column import serialization  # pylint: disable=g-import-not-at-top
      column_configs = serialization.serialize_feature_columns(
          self._feature_columns)
      config = {'feature_columns': column_configs}
  
      base_config = super(  # pylint: disable=bad-super-call
          _BaseFeaturesLayer, self).get_config()
      return dict(list(base_config.items()) + list(config.items()))
  
    @classmethod
    def from_config(cls, config, custom_objects=None):
      # Import here to avoid circular imports.
      from tensorflow.python.feature_column import serialization  # pylint: disable=g-import-not-at-top
      config_cp = config.copy()
      config_cp['feature_columns'] = serialization.deserialize_feature_columns(
          config['feature_columns'], custom_objects=custom_objects)
  
      return cls(**config_cp)
  
  
  class _LinearModelLayer(Layer):
    """Layer that contains logic for `LinearModel`."""
  
    def __init__(self,
                 feature_columns,
                 units=1,
                 sparse_combiner='sum',
                 trainable=True,
                 name=None,
                 **kwargs):
      super(_LinearModelLayer, self).__init__(
          name=name, trainable=trainable, **kwargs)
  
      self._feature_columns = _normalize_feature_columns(feature_columns)
      for column in self._feature_columns:
        if not isinstance(column, (DenseColumn, CategoricalColumn)):
          raise ValueError(
              'Items of feature_columns must be either a '
              'DenseColumn or CategoricalColumn. Given: {}'.format(column))
  
      self._units = units
      self._sparse_combiner = sparse_combiner
  
      self._state_manager = _StateManagerImpl(self, self.trainable)
      self.bias = None
  
    def build(self, _):
      # We need variable scopes for now because we want the variable partitioning
      # information to percolate down. We also use _pure_variable_scope's here
      # since we want to open up a name_scope in the `call` method while creating
      # the ops.
      with variable_scope._pure_variable_scope(self.name):  # pylint: disable=protected-access
        for column in self._feature_columns:
          with variable_scope._pure_variable_scope(column.name):  # pylint: disable=protected-access
            # Create the state for each feature column
            column.create_state(self._state_manager)
  
            # Create a weight variable for each column.
            if isinstance(column, CategoricalColumn):
              first_dim = column.num_buckets
            else:
              first_dim = column.variable_shape.num_elements()
            self._state_manager.create_variable(
                column,
                name='weights',
                dtype=dtypes.float32,
                shape=(first_dim, self._units),
                initializer=init_ops.zeros_initializer(),
                trainable=self.trainable)
  
        # Create a bias variable.
        self.bias = self.add_variable(
            name='bias_weights',
            dtype=dtypes.float32,
            shape=[self._units],
            initializer=init_ops.zeros_initializer(),
            trainable=self.trainable,
            use_resource=True,
            # TODO(rohanj): Get rid of this hack once we have a mechanism for
            # specifying a default partitioner for an entire layer. In that case,
            # the default getter for Layers should work.
            getter=variable_scope.get_variable)
  
      super(_LinearModelLayer, self).build(None)
  
    def call(self, features):
      if not isinstance(features, dict):
        raise ValueError('We expected a dictionary here. Instead we got: {}'
                         .format(features))
      with ops.name_scope(self.name):
        transformation_cache = FeatureTransformationCache(features)
        weighted_sums = []
        for column in self._feature_columns:
          with ops.name_scope(column.name):
            # All the weights used in the linear model are owned by the state
            # manager associated with this Linear Model.
            weight_var = self._state_manager.get_variable(column, 'weights')
  
            weighted_sum = _create_weighted_sum(
                column=column,
                transformation_cache=transformation_cache,
                state_manager=self._state_manager,
                sparse_combiner=self._sparse_combiner,
                weight_var=weight_var)
            weighted_sums.append(weighted_sum)
  
        _verify_static_batch_size_equality(weighted_sums, self._feature_columns)
        predictions_no_bias = math_ops.add_n(
            weighted_sums, name='weighted_sum_no_bias')
        predictions = nn_ops.bias_add(
            predictions_no_bias, self.bias, name='weighted_sum')
        return predictions
  
    def get_config(self):
      # Import here to avoid circular imports.
      from tensorflow.python.feature_column import serialization  # pylint: disable=g-import-not-at-top
      column_configs = serialization.serialize_feature_columns(
          self._feature_columns)
      config = {
          'feature_columns': column_configs,
          'units': self._units,
          'sparse_combiner': self._sparse_combiner
      }
  
      base_config = super(  # pylint: disable=bad-super-call
          _LinearModelLayer, self).get_config()
      return dict(list(base_config.items()) + list(config.items()))
  
    @classmethod
    def from_config(cls, config, custom_objects=None):
      # Import here to avoid circular imports.
      from tensorflow.python.feature_column import serialization  # pylint: disable=g-import-not-at-top
      config_cp = config.copy()
      columns = serialization.deserialize_feature_columns(
          config_cp['feature_columns'], custom_objects=custom_objects)
  
      del config_cp['feature_columns']
      return cls(feature_columns=columns, **config_cp)
  
  
  # TODO(tanzheny): Cleanup it with respect to Premade model b/132690565.
  class LinearModel(training.Model):
    """Produces a linear prediction `Tensor` based on given `feature_columns`.
  
    This layer generates a weighted sum based on output dimension `units`.
    Weighted sum refers to logits in classification problems. It refers to the
    prediction itself for linear regression problems.
  
    Note on supported columns: `LinearLayer` treats categorical columns as
    `indicator_column`s. To be specific, assume the input as `SparseTensor` looks
    like:
  
    ```python
      shape = [2, 2]
      {
          [0, 0]: "a"
          [1, 0]: "b"
          [1, 1]: "c"
      }
    ```
    `linear_model` assigns weights for the presence of "a", "b", "c' implicitly,
    just like `indicator_column`, while `input_layer` explicitly requires wrapping
    each of categorical columns with an `embedding_column` or an
    `indicator_column`.
  
    Example of usage:
  
    ```python
    price = numeric_column('price')
    price_buckets = bucketized_column(price, boundaries=[0., 10., 100., 1000.])
    keywords = categorical_column_with_hash_bucket("keywords", 10K)
    keywords_price = crossed_column('keywords', price_buckets, ...)
    columns = [price_buckets, keywords, keywords_price ...]
    linear_model = LinearLayer(columns)
  
    features = tf.io.parse_example(..., features=make_parse_example_spec(columns))
    prediction = linear_model(features)
    ```
    """
  
    def __init__(self,
                 feature_columns,
                 units=1,
                 sparse_combiner='sum',
                 trainable=True,
                 name=None,
                 **kwargs):
      """Constructs a LinearLayer.
  
      Args:
        feature_columns: An iterable containing the FeatureColumns to use as
          inputs to your model. All items should be instances of classes derived
          from `_FeatureColumn`s.
        units: An integer, dimensionality of the output space. Default value is 1.
        sparse_combiner: A string specifying how to reduce if a categorical column
          is multivalent. Except `numeric_column`, almost all columns passed to
          `linear_model` are considered as categorical columns.  It combines each
          categorical column independently. Currently "mean", "sqrtn" and "sum"
          are supported, with "sum" the default for linear model. "sqrtn" often
          achieves good accuracy, in particular with bag-of-words columns.
            * "sum": do not normalize features in the column
            * "mean": do l1 normalization on features in the column
            * "sqrtn": do l2 normalization on features in the column
          For example, for two features represented as the categorical columns:
  
            ```python
            # Feature 1
  
            shape = [2, 2]
            {
                [0, 0]: "a"
                [0, 1]: "b"
                [1, 0]: "c"
            }
  
            # Feature 2
  
            shape = [2, 3]
            {
                [0, 0]: "d"
                [1, 0]: "e"
                [1, 1]: "f"
                [1, 2]: "g"
            }
            ```
  
          with `sparse_combiner` as "mean", the linear model outputs conceptly are
          ```
          y_0 = 1.0 / 2.0 * ( w_a + w_ b) + w_c + b_0
          y_1 = w_d + 1.0 / 3.0 * ( w_e + w_ f + w_g) + b_1
          ```
          where `y_i` is the output, `b_i` is the bias, and `w_x` is the weight
          assigned to the presence of `x` in the input features.
        trainable: If `True` also add the variable to the graph collection
          `GraphKeys.TRAINABLE_VARIABLES` (see `tf.Variable`).
        name: Name to give to the Linear Model. All variables and ops created will
          be scoped by this name.
        **kwargs: Keyword arguments to construct a layer.
  
      Raises:
        ValueError: if an item in `feature_columns` is neither a `DenseColumn`
          nor `CategoricalColumn`.
      """
  
      super(LinearModel, self).__init__(name=name, **kwargs)
      self.layer = _LinearModelLayer(
          feature_columns,
          units,
          sparse_combiner,
          trainable,
          name=self.name,
          **kwargs)
  
    def call(self, features):
      """Returns a `Tensor` the represents the predictions of a linear model.
  
      Args:
        features: A mapping from key to tensors. `_FeatureColumn`s look up via
          these keys. For example `numeric_column('price')` will look at 'price'
          key in this dict. Values are `Tensor` or `SparseTensor` depending on
          corresponding `_FeatureColumn`.
  
      Returns:
        A `Tensor` which represents predictions/logits of a linear model. Its
        shape is (batch_size, units) and its dtype is `float32`.
  
      Raises:
        ValueError: If features are not a dictionary.
      """
      return self.layer(features)
  
    @property
    def bias(self):
      return self.layer.bias
  
  
  def _transform_features_v2(features, feature_columns, state_manager):
    """Returns transformed features based on features columns passed in.
  
    Please note that most probably you would not need to use this function. Please
    check `input_layer` and `linear_model` to see whether they will
    satisfy your use case or not.
  
    Example:
  
    ```python
    # Define features and transformations
    crosses_a_x_b = crossed_column(
        columns=["sparse_feature_a", "sparse_feature_b"], hash_bucket_size=10000)
    price_buckets = bucketized_column(
        source_column=numeric_column("price"), boundaries=[...])
  
    columns = [crosses_a_x_b, price_buckets]
    features = tf.io.parse_example(..., features=make_parse_example_spec(columns))
    transformed = transform_features(features=features, feature_columns=columns)
  
    assertCountEqual(columns, transformed.keys())
    ```
  
    Args:
      features: A mapping from key to tensors. `FeatureColumn`s look up via these
        keys. For example `numeric_column('price')` will look at 'price' key in
        this dict. Values can be a `SparseTensor` or a `Tensor` depends on
        corresponding `FeatureColumn`.
      feature_columns: An iterable containing all the `FeatureColumn`s.
      state_manager: A StateManager object that holds the FeatureColumn state.
  
    Returns:
      A `dict` mapping `FeatureColumn` to `Tensor` and `SparseTensor` values.
    """
    feature_columns = _normalize_feature_columns(feature_columns)
    outputs = {}
    with ops.name_scope(
        None, default_name='transform_features', values=features.values()):
      transformation_cache = FeatureTransformationCache(features)
      for column in feature_columns:
        with ops.name_scope(None, default_name=column.name):
          outputs[column] = transformation_cache.get(column, state_manager)
    return outputs
  
  
  @tf_export('feature_column.make_parse_example_spec', v1=[])
  def make_parse_example_spec_v2(feature_columns):
    """Creates parsing spec dictionary from input feature_columns.
  
    The returned dictionary can be used as arg 'features' in
    `tf.io.parse_example`.
  
    Typical usage example:
  
    ```python
    # Define features and transformations
    feature_a = categorical_column_with_vocabulary_file(...)
    feature_b = numeric_column(...)
    feature_c_bucketized = bucketized_column(numeric_column("feature_c"), ...)
    feature_a_x_feature_c = crossed_column(
        columns=["feature_a", feature_c_bucketized], ...)
  
    feature_columns = set(
        [feature_b, feature_c_bucketized, feature_a_x_feature_c])
    features = tf.io.parse_example(
        serialized=serialized_examples,
        features=make_parse_example_spec(feature_columns))
    ```
  
    For the above example, make_parse_example_spec would return the dict:
  
    ```python
    {
        "feature_a": parsing_ops.VarLenFeature(tf.string),
        "feature_b": parsing_ops.FixedLenFeature([1], dtype=tf.float32),
        "feature_c": parsing_ops.FixedLenFeature([1], dtype=tf.float32)
    }
    ```
  
    Args:
      feature_columns: An iterable containing all feature columns. All items
        should be instances of classes derived from `FeatureColumn`.
  
    Returns:
      A dict mapping each feature key to a `FixedLenFeature` or `VarLenFeature`
      value.
  
    Raises:
      ValueError: If any of the given `feature_columns` is not a `FeatureColumn`
        instance.
    """
    result = {}
    for column in feature_columns:
      if not isinstance(column, FeatureColumn):
        raise ValueError('All feature_columns must be FeatureColumn instances. '
                         'Given: {}'.format(column))
      config = column.parse_example_spec
      for key, value in six.iteritems(config):
        if key in result and value != result[key]:
          raise ValueError(
              'feature_columns contain different parse_spec for key '
              '{}. Given {} and {}'.format(key, value, result[key]))
      result.update(config)
    return result
  
  
  @tf_export('feature_column.embedding_column')
  def embedding_column(categorical_column,
                       dimension,
                       combiner='mean',
                       initializer=None,
                       ckpt_to_load_from=None,
                       tensor_name_in_ckpt=None,
                       max_norm=None,
                       trainable=True):
    """`DenseColumn` that converts from sparse, categorical input.
  
    Use this when your inputs are sparse, but you want to convert them to a dense
    representation (e.g., to feed to a DNN).
  
    Inputs must be a `CategoricalColumn` created by any of the
    `categorical_column_*` function. Here is an example of using
    `embedding_column` with `DNNClassifier`:
  
    ```python
    video_id = categorical_column_with_identity(
        key='video_id', num_buckets=1000000, default_value=0)
    columns = [embedding_column(video_id, 9),...]
  
    estimator = tf.estimator.DNNClassifier(feature_columns=columns, ...)
  
    label_column = ...
    def input_fn():
      features = tf.io.parse_example(
          ..., features=make_parse_example_spec(columns + [label_column]))
      labels = features.pop(label_column.name)
      return features, labels
  
    estimator.train(input_fn=input_fn, steps=100)
    ```
  
    Here is an example using `embedding_column` with model_fn:
  
    ```python
    def model_fn(features, ...):
      video_id = categorical_column_with_identity(
          key='video_id', num_buckets=1000000, default_value=0)
      columns = [embedding_column(video_id, 9),...]
      dense_tensor = input_layer(features, columns)
      # Form DNN layers, calculate loss, and return EstimatorSpec.
      ...
    ```
  
    Args:
      categorical_column: A `CategoricalColumn` created by a
        `categorical_column_with_*` function. This column produces the sparse IDs
        that are inputs to the embedding lookup.
      dimension: An integer specifying dimension of the embedding, must be > 0.
      combiner: A string specifying how to reduce if there are multiple entries in
        a single row. Currently 'mean', 'sqrtn' and 'sum' are supported, with
        'mean' the default. 'sqrtn' often achieves good accuracy, in particular
        with bag-of-words columns. Each of this can be thought as example level
        normalizations on the column. For more information, see
        `tf.embedding_lookup_sparse`.
      initializer: A variable initializer function to be used in embedding
        variable initialization. If not specified, defaults to
        `truncated_normal_initializer` with mean `0.0` and
        standard deviation `1/sqrt(dimension)`.
      ckpt_to_load_from: String representing checkpoint name/pattern from which to
        restore column weights. Required if `tensor_name_in_ckpt` is not `None`.
      tensor_name_in_ckpt: Name of the `Tensor` in `ckpt_to_load_from` from which
        to restore the column weights. Required if `ckpt_to_load_from` is not
        `None`.
      max_norm: If not `None`, embedding values are l2-normalized to this value.
      trainable: Whether or not the embedding is trainable. Default is True.
  
    Returns:
      `DenseColumn` that converts from sparse input.
  
    Raises:
      ValueError: if `dimension` not > 0.
      ValueError: if exactly one of `ckpt_to_load_from` and `tensor_name_in_ckpt`
        is specified.
      ValueError: if `initializer` is specified and is not callable.
      RuntimeError: If eager execution is enabled.
    """
    if (dimension is None) or (dimension < 1):
      raise ValueError('Invalid dimension {}.'.format(dimension))
    if (ckpt_to_load_from is None) != (tensor_name_in_ckpt is None):
      raise ValueError('Must specify both `ckpt_to_load_from` and '
                       '`tensor_name_in_ckpt` or none of them.')
  
    if (initializer is not None) and (not callable(initializer)):
      raise ValueError('initializer must be callable if specified. '
                       'Embedding of column_name: {}'.format(
                           categorical_column.name))
    if initializer is None:
      initializer = init_ops.truncated_normal_initializer(
          mean=0.0, stddev=1 / math.sqrt(dimension))
  
    return EmbeddingColumn(
        categorical_column=categorical_column,
        dimension=dimension,
        combiner=combiner,
        initializer=initializer,
        ckpt_to_load_from=ckpt_to_load_from,
        tensor_name_in_ckpt=tensor_name_in_ckpt,
        max_norm=max_norm,
        trainable=trainable)
  
  
  @tf_export(v1=['feature_column.shared_embedding_columns'])
  def shared_embedding_columns(categorical_columns,
                               dimension,
                               combiner='mean',
                               initializer=None,
                               shared_embedding_collection_name=None,
                               ckpt_to_load_from=None,
                               tensor_name_in_ckpt=None,
                               max_norm=None,
                               trainable=True):
    """List of dense columns that convert from sparse, categorical input.
  
    This is similar to `embedding_column`, except that it produces a list of
    embedding columns that share the same embedding weights.
  
    Use this when your inputs are sparse and of the same type (e.g. watched and
    impression video IDs that share the same vocabulary), and you want to convert
    them to a dense representation (e.g., to feed to a DNN).
  
    Inputs must be a list of categorical columns created by any of the
    `categorical_column_*` function. They must all be of the same type and have
    the same arguments except `key`. E.g. they can be
    categorical_column_with_vocabulary_file with the same vocabulary_file. Some or
    all columns could also be weighted_categorical_column.
  
    Here is an example embedding of two features for a DNNClassifier model:
  
    ```python
    watched_video_id = categorical_column_with_vocabulary_file(
        'watched_video_id', video_vocabulary_file, video_vocabulary_size)
    impression_video_id = categorical_column_with_vocabulary_file(
        'impression_video_id', video_vocabulary_file, video_vocabulary_size)
    columns = shared_embedding_columns(
        [watched_video_id, impression_video_id], dimension=10)
  
    estimator = tf.estimator.DNNClassifier(feature_columns=columns, ...)
  
    label_column = ...
    def input_fn():
      features = tf.io.parse_example(
          ..., features=make_parse_example_spec(columns + [label_column]))
      labels = features.pop(label_column.name)
      return features, labels
  
    estimator.train(input_fn=input_fn, steps=100)
    ```
  
    Here is an example using `shared_embedding_columns` with model_fn:
  
    ```python
    def model_fn(features, ...):
      watched_video_id = categorical_column_with_vocabulary_file(
          'watched_video_id', video_vocabulary_file, video_vocabulary_size)
      impression_video_id = categorical_column_with_vocabulary_file(
          'impression_video_id', video_vocabulary_file, video_vocabulary_size)
      columns = shared_embedding_columns(
          [watched_video_id, impression_video_id], dimension=10)
      dense_tensor = input_layer(features, columns)
      # Form DNN layers, calculate loss, and return EstimatorSpec.
      ...
    ```
  
    Args:
      categorical_columns: List of categorical columns created by a
        `categorical_column_with_*` function. These columns produce the sparse IDs
        that are inputs to the embedding lookup. All columns must be of the same
        type and have the same arguments except `key`. E.g. they can be
        categorical_column_with_vocabulary_file with the same vocabulary_file.
        Some or all columns could also be weighted_categorical_column.
      dimension: An integer specifying dimension of the embedding, must be > 0.
      combiner: A string specifying how to reduce if there are multiple entries in
        a single row. Currently 'mean', 'sqrtn' and 'sum' are supported, with
        'mean' the default. 'sqrtn' often achieves good accuracy, in particular
        with bag-of-words columns. Each of this can be thought as example level
        normalizations on the column. For more information, see
        `tf.embedding_lookup_sparse`.
      initializer: A variable initializer function to be used in embedding
        variable initialization. If not specified, defaults to
        `truncated_normal_initializer` with mean `0.0` and
        standard deviation `1/sqrt(dimension)`.
      shared_embedding_collection_name: Optional name of the collection where
        shared embedding weights are added. If not given, a reasonable name will
        be chosen based on the names of `categorical_columns`. This is also used
        in `variable_scope` when creating shared embedding weights.
      ckpt_to_load_from: String representing checkpoint name/pattern from which to
        restore column weights. Required if `tensor_name_in_ckpt` is not `None`.
      tensor_name_in_ckpt: Name of the `Tensor` in `ckpt_to_load_from` from which
        to restore the column weights. Required if `ckpt_to_load_from` is not
        `None`.
      max_norm: If not `None`, each embedding is clipped if its l2-norm is larger
        than this value, before combining.
      trainable: Whether or not the embedding is trainable. Default is True.
  
    Returns:
      A list of dense columns that converts from sparse input. The order of
      results follows the ordering of `categorical_columns`.
  
    Raises:
      ValueError: if `dimension` not > 0.
      ValueError: if any of the given `categorical_columns` is of different type
        or has different arguments than the others.
      ValueError: if exactly one of `ckpt_to_load_from` and `tensor_name_in_ckpt`
        is specified.
      ValueError: if `initializer` is specified and is not callable.
      RuntimeError: if eager execution is enabled.
    """
    if context.executing_eagerly():
      raise RuntimeError('shared_embedding_columns are not supported when eager '
                         'execution is enabled.')
  
    if (dimension is None) or (dimension < 1):
      raise ValueError('Invalid dimension {}.'.format(dimension))
    if (ckpt_to_load_from is None) != (tensor_name_in_ckpt is None):
      raise ValueError('Must specify both `ckpt_to_load_from` and '
                       '`tensor_name_in_ckpt` or none of them.')
  
    if (initializer is not None) and (not callable(initializer)):
      raise ValueError('initializer must be callable if specified.')
    if initializer is None:
      initializer = init_ops.truncated_normal_initializer(
          mean=0.0, stddev=1. / math.sqrt(dimension))
  
    # Sort the columns so the default collection name is deterministic even if the
    # user passes columns from an unsorted collection, such as dict.values().
    sorted_columns = sorted(categorical_columns, key=lambda x: x.name)
  
    c0 = sorted_columns[0]
    num_buckets = c0._num_buckets  # pylint: disable=protected-access
    if not isinstance(c0, fc_old._CategoricalColumn):  # pylint: disable=protected-access
      raise ValueError(
          'All categorical_columns must be subclasses of _CategoricalColumn. '
          'Given: {}, of type: {}'.format(c0, type(c0)))
    if isinstance(c0,
                  (fc_old._WeightedCategoricalColumn, WeightedCategoricalColumn)):  # pylint: disable=protected-access
      c0 = c0.categorical_column
    for c in sorted_columns[1:]:
      if isinstance(
          c, (fc_old._WeightedCategoricalColumn, WeightedCategoricalColumn)):  # pylint: disable=protected-access
        c = c.categorical_column
      if not isinstance(c, type(c0)):
        raise ValueError(
            'To use shared_embedding_column, all categorical_columns must have '
            'the same type, or be weighted_categorical_column of the same type. '
            'Given column: {} of type: {} does not match given column: {} of '
            'type: {}'.format(c0, type(c0), c, type(c)))
      if num_buckets != c._num_buckets:  # pylint: disable=protected-access
        raise ValueError(
            'To use shared_embedding_column, all categorical_columns must have '
            'the same number of buckets. Given column: {} with buckets: {} does  '
            'not match column: {} with buckets: {}'.format(
                c0, num_buckets, c, c._num_buckets))  # pylint: disable=protected-access
  
    if not shared_embedding_collection_name:
      shared_embedding_collection_name = '_'.join(c.name for c in sorted_columns)
      shared_embedding_collection_name += '_shared_embedding'
  
    result = []
    for column in categorical_columns:
      result.append(
          fc_old._SharedEmbeddingColumn(  # pylint: disable=protected-access
              categorical_column=column,
              initializer=initializer,
              dimension=dimension,
              combiner=combiner,
              shared_embedding_collection_name=shared_embedding_collection_name,
              ckpt_to_load_from=ckpt_to_load_from,
              tensor_name_in_ckpt=tensor_name_in_ckpt,
              max_norm=max_norm,
              trainable=trainable))
  
    return result
  
  
  @tf_export('feature_column.shared_embeddings', v1=[])
  def shared_embedding_columns_v2(categorical_columns,
                                  dimension,
                                  combiner='mean',
                                  initializer=None,
                                  shared_embedding_collection_name=None,
                                  ckpt_to_load_from=None,
                                  tensor_name_in_ckpt=None,
                                  max_norm=None,
                                  trainable=True):
    """List of dense columns that convert from sparse, categorical input.
  
    This is similar to `embedding_column`, except that it produces a list of
    embedding columns that share the same embedding weights.
  
    Use this when your inputs are sparse and of the same type (e.g. watched and
    impression video IDs that share the same vocabulary), and you want to convert
    them to a dense representation (e.g., to feed to a DNN).
  
    Inputs must be a list of categorical columns created by any of the
    `categorical_column_*` function. They must all be of the same type and have
    the same arguments except `key`. E.g. they can be
    categorical_column_with_vocabulary_file with the same vocabulary_file. Some or
    all columns could also be weighted_categorical_column.
  
    Here is an example embedding of two features for a DNNClassifier model:
  
    ```python
    watched_video_id = categorical_column_with_vocabulary_file(
        'watched_video_id', video_vocabulary_file, video_vocabulary_size)
    impression_video_id = categorical_column_with_vocabulary_file(
        'impression_video_id', video_vocabulary_file, video_vocabulary_size)
    columns = shared_embedding_columns(
        [watched_video_id, impression_video_id], dimension=10)
  
    estimator = tf.estimator.DNNClassifier(feature_columns=columns, ...)
  
    label_column = ...
    def input_fn():
      features = tf.io.parse_example(
          ..., features=make_parse_example_spec(columns + [label_column]))
      labels = features.pop(label_column.name)
      return features, labels
  
    estimator.train(input_fn=input_fn, steps=100)
    ```
  
    Here is an example using `shared_embedding_columns` with model_fn:
  
    ```python
    def model_fn(features, ...):
      watched_video_id = categorical_column_with_vocabulary_file(
          'watched_video_id', video_vocabulary_file, video_vocabulary_size)
      impression_video_id = categorical_column_with_vocabulary_file(
          'impression_video_id', video_vocabulary_file, video_vocabulary_size)
      columns = shared_embedding_columns(
          [watched_video_id, impression_video_id], dimension=10)
      dense_tensor = input_layer(features, columns)
      # Form DNN layers, calculate loss, and return EstimatorSpec.
      ...
    ```
  
    Args:
      categorical_columns: List of categorical columns created by a
        `categorical_column_with_*` function. These columns produce the sparse IDs
        that are inputs to the embedding lookup. All columns must be of the same
        type and have the same arguments except `key`. E.g. they can be
        categorical_column_with_vocabulary_file with the same vocabulary_file.
        Some or all columns could also be weighted_categorical_column.
      dimension: An integer specifying dimension of the embedding, must be > 0.
      combiner: A string specifying how to reduce if there are multiple entries
        in a single row. Currently 'mean', 'sqrtn' and 'sum' are supported, with
        'mean' the default. 'sqrtn' often achieves good accuracy, in particular
        with bag-of-words columns. Each of this can be thought as example level
        normalizations on the column. For more information, see
        `tf.embedding_lookup_sparse`.
      initializer: A variable initializer function to be used in embedding
        variable initialization. If not specified, defaults to
        `truncated_normal_initializer` with mean `0.0` and standard
        deviation `1/sqrt(dimension)`.
      shared_embedding_collection_name: Optional collective name of these columns.
        If not given, a reasonable name will be chosen based on the names of
        `categorical_columns`.
      ckpt_to_load_from: String representing checkpoint name/pattern from which to
        restore column weights. Required if `tensor_name_in_ckpt` is not `None`.
      tensor_name_in_ckpt: Name of the `Tensor` in `ckpt_to_load_from` from
        which to restore the column weights. Required if `ckpt_to_load_from` is
        not `None`.
      max_norm: If not `None`, each embedding is clipped if its l2-norm is
        larger than this value, before combining.
      trainable: Whether or not the embedding is trainable. Default is True.
  
    Returns:
      A list of dense columns that converts from sparse input. The order of
      results follows the ordering of `categorical_columns`.
  
    Raises:
      ValueError: if `dimension` not > 0.
      ValueError: if any of the given `categorical_columns` is of different type
        or has different arguments than the others.
      ValueError: if exactly one of `ckpt_to_load_from` and `tensor_name_in_ckpt`
        is specified.
      ValueError: if `initializer` is specified and is not callable.
      RuntimeError: if eager execution is enabled.
    """
    if context.executing_eagerly():
      raise RuntimeError('shared_embedding_columns are not supported when eager '
                         'execution is enabled.')
  
    if (dimension is None) or (dimension < 1):
      raise ValueError('Invalid dimension {}.'.format(dimension))
    if (ckpt_to_load_from is None) != (tensor_name_in_ckpt is None):
      raise ValueError('Must specify both `ckpt_to_load_from` and '
                       '`tensor_name_in_ckpt` or none of them.')
  
    if (initializer is not None) and (not callable(initializer)):
      raise ValueError('initializer must be callable if specified.')
    if initializer is None:
      initializer = init_ops.truncated_normal_initializer(
          mean=0.0, stddev=1. / math.sqrt(dimension))
  
    # Sort the columns so the default collection name is deterministic even if the
    # user passes columns from an unsorted collection, such as dict.values().
    sorted_columns = sorted(categorical_columns, key=lambda x: x.name)
  
    c0 = sorted_columns[0]
    num_buckets = c0.num_buckets
    if not isinstance(c0, CategoricalColumn):
      raise ValueError(
          'All categorical_columns must be subclasses of CategoricalColumn. '
          'Given: {}, of type: {}'.format(c0, type(c0)))
    if isinstance(c0, WeightedCategoricalColumn):
      c0 = c0.categorical_column
    for c in sorted_columns[1:]:
      if isinstance(c, WeightedCategoricalColumn):
        c = c.categorical_column
      if not isinstance(c, type(c0)):
        raise ValueError(
            'To use shared_embedding_column, all categorical_columns must have '
            'the same type, or be weighted_categorical_column of the same type. '
            'Given column: {} of type: {} does not match given column: {} of '
            'type: {}'.format(c0, type(c0), c, type(c)))
      if num_buckets != c.num_buckets:
        raise ValueError(
            'To use shared_embedding_column, all categorical_columns must have '
            'the same number of buckets. Given column: {} with buckets: {} does  '
            'not match column: {} with buckets: {}'.format(
                c0, num_buckets, c, c.num_buckets))
  
    if not shared_embedding_collection_name:
      shared_embedding_collection_name = '_'.join(c.name for c in sorted_columns)
      shared_embedding_collection_name += '_shared_embedding'
  
    column_creator = SharedEmbeddingColumnCreator(
        dimension, initializer, ckpt_to_load_from, tensor_name_in_ckpt,
        num_buckets, trainable, shared_embedding_collection_name)
  
    result = []
    for column in categorical_columns:
      result.append(
          column_creator(
              categorical_column=column, combiner=combiner, max_norm=max_norm))
  
    return result
  
  
  @tf_export('feature_column.numeric_column')
  def numeric_column(key,
                     shape=(1,),
                     default_value=None,
                     dtype=dtypes.float32,
                     normalizer_fn=None):
    """Represents real valued or numerical features.
  
    Example:
  
    ```python
    price = numeric_column('price')
    columns = [price, ...]
    features = tf.io.parse_example(..., features=make_parse_example_spec(columns))
    dense_tensor = input_layer(features, columns)
  
    # or
    bucketized_price = bucketized_column(price, boundaries=[...])
    columns = [bucketized_price, ...]
    features = tf.io.parse_example(..., features=make_parse_example_spec(columns))
    linear_prediction = linear_model(features, columns)
    ```
  
    Args:
      key: A unique string identifying the input feature. It is used as the
        column name and the dictionary key for feature parsing configs, feature
        `Tensor` objects, and feature columns.
      shape: An iterable of integers specifies the shape of the `Tensor`. An
        integer can be given which means a single dimension `Tensor` with given
        width. The `Tensor` representing the column will have the shape of
        [batch_size] + `shape`.
      default_value: A single value compatible with `dtype` or an iterable of
        values compatible with `dtype` which the column takes on during
        `tf.Example` parsing if data is missing. A default value of `None` will
        cause `tf.io.parse_example` to fail if an example does not contain this
        column. If a single value is provided, the same value will be applied as
        the default value for every item. If an iterable of values is provided,
        the shape of the `default_value` should be equal to the given `shape`.
      dtype: defines the type of values. Default value is `tf.float32`. Must be a
        non-quantized, real integer or floating point type.
      normalizer_fn: If not `None`, a function that can be used to normalize the
        value of the tensor after `default_value` is applied for parsing.
        Normalizer function takes the input `Tensor` as its argument, and returns
        the output `Tensor`. (e.g. lambda x: (x - 3.0) / 4.2). Please note that
        even though the most common use case of this function is normalization, it
        can be used for any kind of Tensorflow transformations.
  
    Returns:
      A `NumericColumn`.
  
    Raises:
      TypeError: if any dimension in shape is not an int
      ValueError: if any dimension in shape is not a positive integer
      TypeError: if `default_value` is an iterable but not compatible with `shape`
      TypeError: if `default_value` is not compatible with `dtype`.
      ValueError: if `dtype` is not convertible to `tf.float32`.
    """
    shape = _check_shape(shape, key)
    if not (dtype.is_integer or dtype.is_floating):
      raise ValueError('dtype must be convertible to float. '
                       'dtype: {}, key: {}'.format(dtype, key))
    default_value = fc_utils.check_default_value(
        shape, default_value, dtype, key)
  
    if normalizer_fn is not None and not callable(normalizer_fn):
      raise TypeError(
          'normalizer_fn must be a callable. Given: {}'.format(normalizer_fn))
  
    fc_utils.assert_key_is_string(key)
    return NumericColumn(
        key,
        shape=shape,
        default_value=default_value,
        dtype=dtype,
        normalizer_fn=normalizer_fn)
  
  
  @tf_export('feature_column.bucketized_column')
  def bucketized_column(source_column, boundaries):
    """Represents discretized dense input.
  
    Buckets include the left boundary, and exclude the right boundary. Namely,
    `boundaries=[0., 1., 2.]` generates buckets `(-inf, 0.)`, `[0., 1.)`,
    `[1., 2.)`, and `[2., +inf)`.
  
    For example, if the inputs are
  
    ```python
    boundaries = [0, 10, 100]
    input tensor = [[-5, 10000]
                    [150,   10]
                    [5,    100]]
    ```
  
    then the output will be
  
    ```python
    output = [[0, 3]
              [3, 2]
              [1, 3]]
    ```
  
    Example:
  
    ```python
    price = numeric_column('price')
    bucketized_price = bucketized_column(price, boundaries=[...])
    columns = [bucketized_price, ...]
    features = tf.io.parse_example(..., features=make_parse_example_spec(columns))
    linear_prediction = linear_model(features, columns)
  
    # or
    columns = [bucketized_price, ...]
    features = tf.io.parse_example(..., features=make_parse_example_spec(columns))
    dense_tensor = input_layer(features, columns)
    ```
  
    `bucketized_column` can also be crossed with another categorical column using
    `crossed_column`:
  
    ```python
    price = numeric_column('price')
    # bucketized_column converts numerical feature to a categorical one.
    bucketized_price = bucketized_column(price, boundaries=[...])
    # 'keywords' is a string feature.
    price_x_keywords = crossed_column([bucketized_price, 'keywords'], 50K)
    columns = [price_x_keywords, ...]
    features = tf.io.parse_example(..., features=make_parse_example_spec(columns))
    linear_prediction = linear_model(features, columns)
    ```
  
    Args:
      source_column: A one-dimensional dense column which is generated with
        `numeric_column`.
      boundaries: A sorted list or tuple of floats specifying the boundaries.
  
    Returns:
      A `BucketizedColumn`.
  
    Raises:
      ValueError: If `source_column` is not a numeric column, or if it is not
        one-dimensional.
      ValueError: If `boundaries` is not a sorted list or tuple.
    """
    if not isinstance(source_column, (NumericColumn, fc_old._NumericColumn)):  # pylint: disable=protected-access
      raise ValueError(
          'source_column must be a column generated with numeric_column(). '
          'Given: {}'.format(source_column))
    if len(source_column.shape) > 1:
      raise ValueError(
          'source_column must be one-dimensional column. '
          'Given: {}'.format(source_column))
    if not boundaries:
      raise ValueError('boundaries must not be empty.')
    if not (isinstance(boundaries, list) or isinstance(boundaries, tuple)):
      raise ValueError('boundaries must be a sorted list.')
    for i in range(len(boundaries) - 1):
      if boundaries[i] >= boundaries[i + 1]:
        raise ValueError('boundaries must be a sorted list.')
    return BucketizedColumn(source_column, tuple(boundaries))
  
  
  @tf_export('feature_column.categorical_column_with_hash_bucket')
  def categorical_column_with_hash_bucket(key,
                                          hash_bucket_size,
                                          dtype=dtypes.string):
    """Represents sparse feature where ids are set by hashing.
  
    Use this when your sparse features are in string or integer format, and you
    want to distribute your inputs into a finite number of buckets by hashing.
    output_id = Hash(input_feature_string) % bucket_size for string type input.
    For int type input, the value is converted to its string representation first
    and then hashed by the same formula.
  
    For input dictionary `features`, `features[key]` is either `Tensor` or
    `SparseTensor`. If `Tensor`, missing values can be represented by `-1` for int
    and `''` for string, which will be dropped by this feature column.
  
    Example:
  
    ```python
    keywords = categorical_column_with_hash_bucket("keywords", 10K)
    columns = [keywords, ...]
    features = tf.io.parse_example(..., features=make_parse_example_spec(columns))
    linear_prediction = linear_model(features, columns)
  
    # or
    keywords_embedded = embedding_column(keywords, 16)
    columns = [keywords_embedded, ...]
    features = tf.io.parse_example(..., features=make_parse_example_spec(columns))
    dense_tensor = input_layer(features, columns)
    ```
  
    Args:
      key: A unique string identifying the input feature. It is used as the
        column name and the dictionary key for feature parsing configs, feature
        `Tensor` objects, and feature columns.
      hash_bucket_size: An int > 1. The number of buckets.
      dtype: The type of features. Only string and integer types are supported.
  
    Returns:
      A `HashedCategoricalColumn`.
  
    Raises:
      ValueError: `hash_bucket_size` is not greater than 1.
      ValueError: `dtype` is neither string nor integer.
    """
    if hash_bucket_size is None:
      raise ValueError('hash_bucket_size must be set. ' 'key: {}'.format(key))
  
    if hash_bucket_size < 1:
      raise ValueError('hash_bucket_size must be at least 1. '
                       'hash_bucket_size: {}, key: {}'.format(
                           hash_bucket_size, key))
  
    fc_utils.assert_key_is_string(key)
    fc_utils.assert_string_or_int(dtype, prefix='column_name: {}'.format(key))
  
    return HashedCategoricalColumn(key, hash_bucket_size, dtype)
  
  
  @tf_export(v1=['feature_column.categorical_column_with_vocabulary_file'])
  def categorical_column_with_vocabulary_file(key,
                                              vocabulary_file,
                                              vocabulary_size=None,
                                              num_oov_buckets=0,
                                              default_value=None,
                                              dtype=dtypes.string):
    """A `CategoricalColumn` with a vocabulary file.
  
    Use this when your inputs are in string or integer format, and you have a
    vocabulary file that maps each value to an integer ID. By default,
    out-of-vocabulary values are ignored. Use either (but not both) of
    `num_oov_buckets` and `default_value` to specify how to include
    out-of-vocabulary values.
  
    For input dictionary `features`, `features[key]` is either `Tensor` or
    `SparseTensor`. If `Tensor`, missing values can be represented by `-1` for int
    and `''` for string, which will be dropped by this feature column.
  
    Example with `num_oov_buckets`:
    File '/us/states.txt' contains 50 lines, each with a 2-character U.S. state
    abbreviation. All inputs with values in that file are assigned an ID 0-49,
    corresponding to its line number. All other values are hashed and assigned an
    ID 50-54.
  
    ```python
    states = categorical_column_with_vocabulary_file(
        key='states', vocabulary_file='/us/states.txt', vocabulary_size=50,
        num_oov_buckets=5)
    columns = [states, ...]
    features = tf.io.parse_example(..., features=make_parse_example_spec(columns))
    linear_prediction = linear_model(features, columns)
    ```
  
    Example with `default_value`:
    File '/us/states.txt' contains 51 lines - the first line is 'XX', and the
    other 50 each have a 2-character U.S. state abbreviation. Both a literal 'XX'
    in input, and other values missing from the file, will be assigned ID 0. All
    others are assigned the corresponding line number 1-50.
  
    ```python
    states = categorical_column_with_vocabulary_file(
        key='states', vocabulary_file='/us/states.txt', vocabulary_size=51,
        default_value=0)
    columns = [states, ...]
    features = tf.io.parse_example(..., features=make_parse_example_spec(columns))
    linear_prediction, _, _ = linear_model(features, columns)
    ```
  
    And to make an embedding with either:
  
    ```python
    columns = [embedding_column(states, 3),...]
    features = tf.io.parse_example(..., features=make_parse_example_spec(columns))
    dense_tensor = input_layer(features, columns)
    ```
  
    Args:
      key: A unique string identifying the input feature. It is used as the
        column name and the dictionary key for feature parsing configs, feature
        `Tensor` objects, and feature columns.
      vocabulary_file: The vocabulary file name.
      vocabulary_size: Number of the elements in the vocabulary. This must be no
        greater than length of `vocabulary_file`, if less than length, later
        values are ignored. If None, it is set to the length of `vocabulary_file`.
      num_oov_buckets: Non-negative integer, the number of out-of-vocabulary
        buckets. All out-of-vocabulary inputs will be assigned IDs in the range
        `[vocabulary_size, vocabulary_size+num_oov_buckets)` based on a hash of
        the input value. A positive `num_oov_buckets` can not be specified with
        `default_value`.
      default_value: The integer ID value to return for out-of-vocabulary feature
        values, defaults to `-1`. This can not be specified with a positive
        `num_oov_buckets`.
      dtype: The type of features. Only string and integer types are supported.
  
    Returns:
      A `CategoricalColumn` with a vocabulary file.
  
    Raises:
      ValueError: `vocabulary_file` is missing or cannot be opened.
      ValueError: `vocabulary_size` is missing or < 1.
      ValueError: `num_oov_buckets` is a negative integer.
      ValueError: `num_oov_buckets` and `default_value` are both specified.
      ValueError: `dtype` is neither string nor integer.
    """
    return categorical_column_with_vocabulary_file_v2(
        key, vocabulary_file, vocabulary_size,
        dtype, default_value,
        num_oov_buckets)
  
  
  @tf_export('feature_column.categorical_column_with_vocabulary_file', v1=[])
  def categorical_column_with_vocabulary_file_v2(key,
                                                 vocabulary_file,
                                                 vocabulary_size=None,
                                                 dtype=dtypes.string,
                                                 default_value=None,
                                                 num_oov_buckets=0):
    """A `CategoricalColumn` with a vocabulary file.
  
    Use this when your inputs are in string or integer format, and you have a
    vocabulary file that maps each value to an integer ID. By default,
    out-of-vocabulary values are ignored. Use either (but not both) of
    `num_oov_buckets` and `default_value` to specify how to include
    out-of-vocabulary values.
  
    For input dictionary `features`, `features[key]` is either `Tensor` or
    `SparseTensor`. If `Tensor`, missing values can be represented by `-1` for int
    and `''` for string, which will be dropped by this feature column.
  
    Example with `num_oov_buckets`:
    File `'/us/states.txt'` contains 50 lines, each with a 2-character U.S. state
    abbreviation. All inputs with values in that file are assigned an ID 0-49,
    corresponding to its line number. All other values are hashed and assigned an
    ID 50-54.
  
    ```python
    states = categorical_column_with_vocabulary_file(
        key='states', vocabulary_file='/us/states.txt', vocabulary_size=50,
        num_oov_buckets=5)
    columns = [states, ...]
    features = tf.io.parse_example(..., features=make_parse_example_spec(columns))
    linear_prediction = linear_model(features, columns)
    ```
  
    Example with `default_value`:
    File `'/us/states.txt'` contains 51 lines - the first line is `'XX'`, and the
    other 50 each have a 2-character U.S. state abbreviation. Both a literal
    `'XX'` in input, and other values missing from the file, will be assigned
    ID 0. All others are assigned the corresponding line number 1-50.
  
    ```python
    states = categorical_column_with_vocabulary_file(
        key='states', vocabulary_file='/us/states.txt', vocabulary_size=51,
        default_value=0)
    columns = [states, ...]
    features = tf.io.parse_example(..., features=make_parse_example_spec(columns))
    linear_prediction, _, _ = linear_model(features, columns)
    ```
  
    And to make an embedding with either:
  
    ```python
    columns = [embedding_column(states, 3),...]
    features = tf.io.parse_example(..., features=make_parse_example_spec(columns))
    dense_tensor = input_layer(features, columns)
    ```
  
    Args:
      key: A unique string identifying the input feature. It is used as the
        column name and the dictionary key for feature parsing configs, feature
        `Tensor` objects, and feature columns.
      vocabulary_file: The vocabulary file name.
      vocabulary_size: Number of the elements in the vocabulary. This must be no
        greater than length of `vocabulary_file`, if less than length, later
        values are ignored. If None, it is set to the length of `vocabulary_file`.
      dtype: The type of features. Only string and integer types are supported.
      default_value: The integer ID value to return for out-of-vocabulary feature
        values, defaults to `-1`. This can not be specified with a positive
        `num_oov_buckets`.
      num_oov_buckets: Non-negative integer, the number of out-of-vocabulary
        buckets. All out-of-vocabulary inputs will be assigned IDs in the range
        `[vocabulary_size, vocabulary_size+num_oov_buckets)` based on a hash of
        the input value. A positive `num_oov_buckets` can not be specified with
        `default_value`.
  
    Returns:
      A `CategoricalColumn` with a vocabulary file.
  
    Raises:
      ValueError: `vocabulary_file` is missing or cannot be opened.
      ValueError: `vocabulary_size` is missing or < 1.
      ValueError: `num_oov_buckets` is a negative integer.
      ValueError: `num_oov_buckets` and `default_value` are both specified.
      ValueError: `dtype` is neither string nor integer.
    """
    if not vocabulary_file:
      raise ValueError('Missing vocabulary_file in {}.'.format(key))
  
    if vocabulary_size is None:
      if not gfile.Exists(vocabulary_file):
        raise ValueError('vocabulary_file in {} does not exist.'.format(key))
  
      with gfile.GFile(vocabulary_file) as f:
        vocabulary_size = sum(1 for _ in f)
      logging.info(
          'vocabulary_size = %d in %s is inferred from the number of elements '
          'in the vocabulary_file %s.', vocabulary_size, key, vocabulary_file)
  
    # `vocabulary_size` isn't required for lookup, but it is for `_num_buckets`.
    if vocabulary_size < 1:
      raise ValueError('Invalid vocabulary_size in {}.'.format(key))
    if num_oov_buckets:
      if default_value is not None:
        raise ValueError(
            'Can\'t specify both num_oov_buckets and default_value in {}.'.format(
                key))
      if num_oov_buckets < 0:
        raise ValueError('Invalid num_oov_buckets {} in {}.'.format(
            num_oov_buckets, key))
    fc_utils.assert_string_or_int(dtype, prefix='column_name: {}'.format(key))
    fc_utils.assert_key_is_string(key)
    return VocabularyFileCategoricalColumn(
        key=key,
        vocabulary_file=vocabulary_file,
        vocabulary_size=vocabulary_size,
        num_oov_buckets=0 if num_oov_buckets is None else num_oov_buckets,
        default_value=-1 if default_value is None else default_value,
        dtype=dtype)
  
  
  @tf_export('feature_column.categorical_column_with_vocabulary_list')
  def categorical_column_with_vocabulary_list(key,
                                              vocabulary_list,
                                              dtype=None,
                                              default_value=-1,
                                              num_oov_buckets=0):
    """A `CategoricalColumn` with in-memory vocabulary.
  
    Use this when your inputs are in string or integer format, and you have an
    in-memory vocabulary mapping each value to an integer ID. By default,
    out-of-vocabulary values are ignored. Use either (but not both) of
    `num_oov_buckets` and `default_value` to specify how to include
    out-of-vocabulary values.
  
    For input dictionary `features`, `features[key]` is either `Tensor` or
    `SparseTensor`. If `Tensor`, missing values can be represented by `-1` for int
    and `''` for string, which will be dropped by this feature column.
  
    Example with `num_oov_buckets`:
    In the following example, each input in `vocabulary_list` is assigned an ID
    0-3 corresponding to its index (e.g., input 'B' produces output 2). All other
    inputs are hashed and assigned an ID 4-5.
  
    ```python
    colors = categorical_column_with_vocabulary_list(
        key='colors', vocabulary_list=('R', 'G', 'B', 'Y'),
        num_oov_buckets=2)
    columns = [colors, ...]
    features = tf.io.parse_example(..., features=make_parse_example_spec(columns))
    linear_prediction, _, _ = linear_model(features, columns)
    ```
  
    Example with `default_value`:
    In the following example, each input in `vocabulary_list` is assigned an ID
    0-4 corresponding to its index (e.g., input 'B' produces output 3). All other
    inputs are assigned `default_value` 0.
  
  
    ```python
    colors = categorical_column_with_vocabulary_list(
        key='colors', vocabulary_list=('X', 'R', 'G', 'B', 'Y'), default_value=0)
    columns = [colors, ...]
    features = tf.io.parse_example(..., features=make_parse_example_spec(columns))
    linear_prediction, _, _ = linear_model(features, columns)
    ```
  
    And to make an embedding with either:
  
    ```python
    columns = [embedding_column(colors, 3),...]
    features = tf.io.parse_example(..., features=make_parse_example_spec(columns))
    dense_tensor = input_layer(features, columns)
    ```
  
    Args:
      key: A unique string identifying the input feature. It is used as the column
        name and the dictionary key for feature parsing configs, feature `Tensor`
        objects, and feature columns.
      vocabulary_list: An ordered iterable defining the vocabulary. Each feature
        is mapped to the index of its value (if present) in `vocabulary_list`.
        Must be castable to `dtype`.
      dtype: The type of features. Only string and integer types are supported. If
        `None`, it will be inferred from `vocabulary_list`.
      default_value: The integer ID value to return for out-of-vocabulary feature
        values, defaults to `-1`. This can not be specified with a positive
        `num_oov_buckets`.
      num_oov_buckets: Non-negative integer, the number of out-of-vocabulary
        buckets. All out-of-vocabulary inputs will be assigned IDs in the range
        `[len(vocabulary_list), len(vocabulary_list)+num_oov_buckets)` based on a
        hash of the input value. A positive `num_oov_buckets` can not be specified
        with `default_value`.
  
    Returns:
      A `CategoricalColumn` with in-memory vocabulary.
  
    Raises:
      ValueError: if `vocabulary_list` is empty, or contains duplicate keys.
      ValueError: `num_oov_buckets` is a negative integer.
      ValueError: `num_oov_buckets` and `default_value` are both specified.
      ValueError: if `dtype` is not integer or string.
    """
    if (vocabulary_list is None) or (len(vocabulary_list) < 1):
      raise ValueError(
          'vocabulary_list {} must be non-empty, column_name: {}'.format(
              vocabulary_list, key))
    if len(set(vocabulary_list)) != len(vocabulary_list):
      raise ValueError(
          'Duplicate keys in vocabulary_list {}, column_name: {}'.format(
              vocabulary_list, key))
    vocabulary_dtype = dtypes.as_dtype(np.array(vocabulary_list).dtype)
    if num_oov_buckets:
      if default_value != -1:
        raise ValueError(
            'Can\'t specify both num_oov_buckets and default_value in {}.'.format(
                key))
      if num_oov_buckets < 0:
        raise ValueError('Invalid num_oov_buckets {} in {}.'.format(
            num_oov_buckets, key))
    fc_utils.assert_string_or_int(
        vocabulary_dtype, prefix='column_name: {} vocabulary'.format(key))
    if dtype is None:
      dtype = vocabulary_dtype
    elif dtype.is_integer != vocabulary_dtype.is_integer:
      raise ValueError(
          'dtype {} and vocabulary dtype {} do not match, column_name: {}'.format(
              dtype, vocabulary_dtype, key))
    fc_utils.assert_string_or_int(dtype, prefix='column_name: {}'.format(key))
    fc_utils.assert_key_is_string(key)
  
    return VocabularyListCategoricalColumn(
        key=key,
        vocabulary_list=tuple(vocabulary_list),
        dtype=dtype,
        default_value=default_value,
        num_oov_buckets=num_oov_buckets)
  
  
  @tf_export('feature_column.categorical_column_with_identity')
  def categorical_column_with_identity(key, num_buckets, default_value=None):
    """A `CategoricalColumn` that returns identity values.
  
    Use this when your inputs are integers in the range `[0, num_buckets)`, and
    you want to use the input value itself as the categorical ID. Values outside
    this range will result in `default_value` if specified, otherwise it will
    fail.
  
    Typically, this is used for contiguous ranges of integer indexes, but
    it doesn't have to be. This might be inefficient, however, if many of IDs
    are unused. Consider `categorical_column_with_hash_bucket` in that case.
  
    For input dictionary `features`, `features[key]` is either `Tensor` or
    `SparseTensor`. If `Tensor`, missing values can be represented by `-1` for int
    and `''` for string, which will be dropped by this feature column.
  
    In the following examples, each input in the range `[0, 1000000)` is assigned
    the same value. All other inputs are assigned `default_value` 0. Note that a
    literal 0 in inputs will result in the same default ID.
  
    Linear model:
  
    ```python
    video_id = categorical_column_with_identity(
        key='video_id', num_buckets=1000000, default_value=0)
    columns = [video_id, ...]
    features = tf.io.parse_example(..., features=make_parse_example_spec(columns))
    linear_prediction, _, _ = linear_model(features, columns)
    ```
  
    Embedding for a DNN model:
  
    ```python
    columns = [embedding_column(video_id, 9),...]
    features = tf.io.parse_example(..., features=make_parse_example_spec(columns))
    dense_tensor = input_layer(features, columns)
    ```
  
    Args:
      key: A unique string identifying the input feature. It is used as the
        column name and the dictionary key for feature parsing configs, feature
        `Tensor` objects, and feature columns.
      num_buckets: Range of inputs and outputs is `[0, num_buckets)`.
      default_value: If `None`, this column's graph operations will fail for
        out-of-range inputs. Otherwise, this value must be in the range
        `[0, num_buckets)`, and will replace inputs in that range.
  
    Returns:
      A `CategoricalColumn` that returns identity values.
  
    Raises:
      ValueError: if `num_buckets` is less than one.
      ValueError: if `default_value` is not in range `[0, num_buckets)`.
    """
    if num_buckets < 1:
      raise ValueError(
          'num_buckets {} < 1, column_name {}'.format(num_buckets, key))
    if (default_value is not None) and (
        (default_value < 0) or (default_value >= num_buckets)):
      raise ValueError(
          'default_value {} not in range [0, {}), column_name {}'.format(
              default_value, num_buckets, key))
    fc_utils.assert_key_is_string(key)
    return IdentityCategoricalColumn(
        key=key, number_buckets=num_buckets, default_value=default_value)
  
  
  @tf_export('feature_column.indicator_column')
  def indicator_column(categorical_column):
    """Represents multi-hot representation of given categorical column.
  
    - For DNN model, `indicator_column` can be used to wrap any
      `categorical_column_*` (e.g., to feed to DNN). Consider to Use
      `embedding_column` if the number of buckets/unique(values) are large.
  
    - For Wide (aka linear) model, `indicator_column` is the internal
      representation for categorical column when passing categorical column
      directly (as any element in feature_columns) to `linear_model`. See
      `linear_model` for details.
  
    ```python
    name = indicator_column(categorical_column_with_vocabulary_list(
        'name', ['bob', 'george', 'wanda'])
    columns = [name, ...]
    features = tf.io.parse_example(..., features=make_parse_example_spec(columns))
    dense_tensor = input_layer(features, columns)
  
    dense_tensor == [[1, 0, 0]]  # If "name" bytes_list is ["bob"]
    dense_tensor == [[1, 0, 1]]  # If "name" bytes_list is ["bob", "wanda"]
    dense_tensor == [[2, 0, 0]]  # If "name" bytes_list is ["bob", "bob"]
    ```
  
    Args:
      categorical_column: A `CategoricalColumn` which is created by
        `categorical_column_with_*` or `crossed_column` functions.
  
    Returns:
      An `IndicatorColumn`.
    """
    return IndicatorColumn(categorical_column)
  
  
  @tf_export('feature_column.weighted_categorical_column')
  def weighted_categorical_column(categorical_column,
                                  weight_feature_key,
                                  dtype=dtypes.float32):
    """Applies weight values to a `CategoricalColumn`.
  
    Use this when each of your sparse inputs has both an ID and a value. For
    example, if you're representing text documents as a collection of word
    frequencies, you can provide 2 parallel sparse input features ('terms' and
    'frequencies' below).
  
    Example:
  
    Input `tf.Example` objects:
  
    ```proto
    [
      features {
        feature {
          key: "terms"
          value {bytes_list {value: "very" value: "model"}}
        }
        feature {
          key: "frequencies"
          value {float_list {value: 0.3 value: 0.1}}
        }
      },
      features {
        feature {
          key: "terms"
          value {bytes_list {value: "when" value: "course" value: "human"}}
        }
        feature {
          key: "frequencies"
          value {float_list {value: 0.4 value: 0.1 value: 0.2}}
        }
      }
    ]
    ```
  
    ```python
    categorical_column = categorical_column_with_hash_bucket(
        column_name='terms', hash_bucket_size=1000)
    weighted_column = weighted_categorical_column(
        categorical_column=categorical_column, weight_feature_key='frequencies')
    columns = [weighted_column, ...]
    features = tf.io.parse_example(..., features=make_parse_example_spec(columns))
    linear_prediction, _, _ = linear_model(features, columns)
    ```
  
    This assumes the input dictionary contains a `SparseTensor` for key
    'terms', and a `SparseTensor` for key 'frequencies'. These 2 tensors must have
    the same indices and dense shape.
  
    Args:
      categorical_column: A `CategoricalColumn` created by
        `categorical_column_with_*` functions.
      weight_feature_key: String key for weight values.
      dtype: Type of weights, such as `tf.float32`. Only float and integer weights
        are supported.
  
    Returns:
      A `CategoricalColumn` composed of two sparse features: one represents id,
      the other represents weight (value) of the id feature in that example.
  
    Raises:
      ValueError: if `dtype` is not convertible to float.
    """
    if (dtype is None) or not (dtype.is_integer or dtype.is_floating):
      raise ValueError('dtype {} is not convertible to float.'.format(dtype))
    return WeightedCategoricalColumn(
        categorical_column=categorical_column,
        weight_feature_key=weight_feature_key,
        dtype=dtype)
  
  
  @tf_export('feature_column.crossed_column')
  def crossed_column(keys, hash_bucket_size, hash_key=None):
    """Returns a column for performing crosses of categorical features.
  
    Crossed features will be hashed according to `hash_bucket_size`. Conceptually,
    the transformation can be thought of as:
      Hash(cartesian product of features) % `hash_bucket_size`
  
    For example, if the input features are:
  
    * SparseTensor referred by first key:
  
      ```python
      shape = [2, 2]
      {
          [0, 0]: "a"
          [1, 0]: "b"
          [1, 1]: "c"
      }
      ```
  
    * SparseTensor referred by second key:
  
      ```python
      shape = [2, 1]
      {
          [0, 0]: "d"
          [1, 0]: "e"
      }
      ```
  
    then crossed feature will look like:
  
    ```python
     shape = [2, 2]
    {
        [0, 0]: Hash64("d", Hash64("a")) % hash_bucket_size
        [1, 0]: Hash64("e", Hash64("b")) % hash_bucket_size
        [1, 1]: Hash64("e", Hash64("c")) % hash_bucket_size
    }
    ```
  
    Here is an example to create a linear model with crosses of string features:
  
    ```python
    keywords_x_doc_terms = crossed_column(['keywords', 'doc_terms'], 50K)
    columns = [keywords_x_doc_terms, ...]
    features = tf.io.parse_example(..., features=make_parse_example_spec(columns))
    linear_prediction = linear_model(features, columns)
    ```
  
    You could also use vocabulary lookup before crossing:
  
    ```python
    keywords = categorical_column_with_vocabulary_file(
        'keywords', '/path/to/vocabulary/file', vocabulary_size=1K)
    keywords_x_doc_terms = crossed_column([keywords, 'doc_terms'], 50K)
    columns = [keywords_x_doc_terms, ...]
    features = tf.io.parse_example(..., features=make_parse_example_spec(columns))
    linear_prediction = linear_model(features, columns)
    ```
  
    If an input feature is of numeric type, you can use
    `categorical_column_with_identity`, or `bucketized_column`, as in the example:
  
    ```python
    # vertical_id is an integer categorical feature.
    vertical_id = categorical_column_with_identity('vertical_id', 10K)
    price = numeric_column('price')
    # bucketized_column converts numerical feature to a categorical one.
    bucketized_price = bucketized_column(price, boundaries=[...])
    vertical_id_x_price = crossed_column([vertical_id, bucketized_price], 50K)
    columns = [vertical_id_x_price, ...]
    features = tf.io.parse_example(..., features=make_parse_example_spec(columns))
    linear_prediction = linear_model(features, columns)
    ```
  
    To use crossed column in DNN model, you need to add it in an embedding column
    as in this example:
  
    ```python
    vertical_id_x_price = crossed_column([vertical_id, bucketized_price], 50K)
    vertical_id_x_price_embedded = embedding_column(vertical_id_x_price, 10)
    dense_tensor = input_layer(features, [vertical_id_x_price_embedded, ...])
    ```
  
    Args:
      keys: An iterable identifying the features to be crossed. Each element can
        be either:
        * string: Will use the corresponding feature which must be of string type.
        * `CategoricalColumn`: Will use the transformed tensor produced by this
          column. Does not support hashed categorical column.
      hash_bucket_size: An int > 1. The number of buckets.
      hash_key: Specify the hash_key that will be used by the `FingerprintCat64`
        function to combine the crosses fingerprints on SparseCrossOp (optional).
  
    Returns:
      A `CrossedColumn`.
  
    Raises:
      ValueError: If `len(keys) < 2`.
      ValueError: If any of the keys is neither a string nor `CategoricalColumn`.
      ValueError: If any of the keys is `HashedCategoricalColumn`.
      ValueError: If `hash_bucket_size < 1`.
    """
    if not hash_bucket_size or hash_bucket_size < 1:
      raise ValueError('hash_bucket_size must be > 1. '
                       'hash_bucket_size: {}'.format(hash_bucket_size))
    if not keys or len(keys) < 2:
      raise ValueError(
          'keys must be a list with length > 1. Given: {}'.format(keys))
    for key in keys:
      if (not isinstance(key, six.string_types) and
          not isinstance(key, (CategoricalColumn, fc_old._CategoricalColumn))):  # pylint: disable=protected-access
        raise ValueError(
            'Unsupported key type. All keys must be either string, or '
            'categorical column except HashedCategoricalColumn. '
            'Given: {}'.format(key))
      if isinstance(key,
                    (HashedCategoricalColumn, fc_old._HashedCategoricalColumn)):  # pylint: disable=protected-access
        raise ValueError(
            'categorical_column_with_hash_bucket is not supported for crossing. '
            'Hashing before crossing will increase probability of collision. '
            'Instead, use the feature name as a string. Given: {}'.format(key))
    return CrossedColumn(
        keys=tuple(keys), hash_bucket_size=hash_bucket_size, hash_key=hash_key)
  
  
  @six.add_metaclass(abc.ABCMeta)
  class FeatureColumn(object):
    """Represents a feature column abstraction.
  
    WARNING: Do not subclass this layer unless you know what you are doing:
    the API is subject to future changes.
  
    To distinguish between the concept of a feature family and a specific binary
    feature within a family, we refer to a feature family like "country" as a
    feature column. For example, we can have a feature in a `tf.Example` format:
      {key: "country",  value: [ "US" ]}
    In this example the value of feature is "US" and "country" refers to the
    column of the feature.
  
    This class is an abstract class. Users should not create instances of this.
    """
  
    @abc.abstractproperty
    def name(self):
      """Returns string. Used for naming."""
      pass
  
    def __lt__(self, other):
      """Allows feature columns to be sorted in Python 3 as they are in Python 2.
  
      Feature columns need to occasionally be sortable, for example when used as
      keys in a features dictionary passed to a layer.
  
      In CPython, `__lt__` must be defined for all objects in the
      sequence being sorted.
  
      If any objects in teh sequence being sorted do not have an `__lt__` method
      compatible with feature column objects (such as strings), then CPython will
      fall back to using the `__gt__` method below.
      https://docs.python.org/3/library/stdtypes.html#list.sort
  
      Args:
        other: The other object to compare to.
  
      Returns:
        True if the string representation of this object is lexicographically less
        than the string representation of `other`. For FeatureColumn objects,
        this looks like "<__main__.FeatureColumn object at 0xa>".
      """
      return str(self) < str(other)
  
    def __gt__(self, other):
      """Allows feature columns to be sorted in Python 3 as they are in Python 2.
  
      Feature columns need to occasionally be sortable, for example when used as
      keys in a features dictionary passed to a layer.
  
      `__gt__` is called when the "other" object being compared during the sort
      does not have `__lt__` defined.
      Example: http://gpaste/4803354716798976
  
      Args:
        other: The other object to compare to.
  
      Returns:
        True if the string representation of this object is lexicographically
        greater than the string representation of `other`. For FeatureColumn
        objects, this looks like "<__main__.FeatureColumn object at 0xa>".
      """
      return str(self) > str(other)
  
    @abc.abstractmethod
    def transform_feature(self, transformation_cache, state_manager):
      """Returns intermediate representation (usually a `Tensor`).
  
      Uses `transformation_cache` to create an intermediate representation
      (usually a `Tensor`) that other feature columns can use.
  
      Example usage of `transformation_cache`:
      Let's say a Feature column depends on raw feature ('raw') and another
      `FeatureColumn` (input_fc). To access corresponding `Tensor`s,
      transformation_cache will be used as follows:
  
      ```python
      raw_tensor = transformation_cache.get('raw', state_manager)
      fc_tensor = transformation_cache.get(input_fc, state_manager)
      ```
  
      Args:
        transformation_cache: A `FeatureTransformationCache` object to access
          features.
        state_manager: A `StateManager` to create / access resources such as
          lookup tables.
  
      Returns:
        Transformed feature `Tensor`.
      """
      pass
  
    @abc.abstractproperty
    def parse_example_spec(self):
      """Returns a `tf.Example` parsing spec as dict.
  
      It is used for get_parsing_spec for `tf.io.parse_example`. Returned spec is
      a dict from keys ('string') to `VarLenFeature`, `FixedLenFeature`, and other
      supported objects. Please check documentation of `tf.io.parse_example` for
      all supported spec objects.
  
      Let's say a Feature column depends on raw feature ('raw') and another
      `FeatureColumn` (input_fc). One possible implementation of
      parse_example_spec is as follows:
  
      ```python
      spec = {'raw': tf.io.FixedLenFeature(...)}
      spec.update(input_fc.parse_example_spec)
      return spec
      ```
      """
      pass
  
    def create_state(self, state_manager):
      """Uses the `state_manager` to create state for the FeatureColumn.
  
      Args:
        state_manager: A `StateManager` to create / access resources such as
          lookup tables and variables.
      """
      pass
  
    @abc.abstractproperty
    def _is_v2_column(self):
      """Returns whether this FeatureColumn is fully conformant to the new API.
  
      This is needed for composition type cases where an EmbeddingColumn etc.
      might take in old categorical columns as input and then we want to use the
      old API.
      """
      pass
  
    @abc.abstractproperty
    def parents(self):
      """Returns a list of immediate raw feature and FeatureColumn dependencies.
  
      For example:
      # For the following feature columns
      a = numeric_column('f1')
      c = crossed_column(a, 'f2')
      # The expected parents are:
      a.parents = ['f1']
      c.parents = [a, 'f2']
      """
      pass
  
    @abc.abstractmethod
    def _get_config(self):
      """Returns the config of the feature column.
  
      A FeatureColumn config is a Python dictionary (serializable) containing the
      configuration of a FeatureColumn. The same FeatureColumn can be
      reinstantiated later from this configuration.
  
      The config of a feature column does not include information about feature
      columns depending on it nor the FeatureColumn class name.
  
      Example with (de)serialization practices followed in this file:
      ```python
      class SerializationExampleFeatureColumn(
          FeatureColumn, collections.namedtuple(
              'SerializationExampleFeatureColumn',
              ('dimension', 'parent', 'dtype', 'normalizer_fn'))):
  
        def _get_config(self):
          # Create a dict from the namedtuple.
          # Python attribute literals can be directly copied from / to the config.
          # For example 'dimension', assuming it is an integer literal.
          config = dict(zip(self._fields, self))
  
          # (De)serialization of parent FeatureColumns should use the provided
          # (de)serialize_feature_column() methods that take care of de-duping.
          config['parent'] = serialize_feature_column(self.parent)
  
          # Many objects provide custom (de)serialization e.g: for tf.DType
          # tf.DType.name, tf.as_dtype() can be used.
          config['dtype'] = self.dtype.name
  
          # Non-trivial dependencies should be Keras-(de)serializable.
          config['normalizer_fn'] = generic_utils.serialize_keras_object(
              self.normalizer_fn)
  
          return config
  
        @classmethod
        def _from_config(cls, config, custom_objects=None, columns_by_name=None):
          # This should do the inverse transform from `_get_config` and construct
          # the namedtuple.
          kwargs = config.copy()
          kwargs['parent'] = deserialize_feature_column(
              config['parent'], custom_objects, columns_by_name)
          kwargs['dtype'] = dtypes.as_dtype(config['dtype'])
          kwargs['normalizer_fn'] = generic_utils.deserialize_keras_object(
            config['normalizer_fn'], custom_objects=custom_objects)
          return cls(**kwargs)
  
      ```
      Returns:
        A serializable Dict that can be used to deserialize the object with
        from_config.
      """
      pass
  
    @classmethod
    def _from_config(cls, config, custom_objects=None, columns_by_name=None):
      """Creates a FeatureColumn from its config.
  
      This method should be the reverse of `_get_config`, capable of instantiating
      the same FeatureColumn from the config dictionary. See `_get_config` for an
      example of common (de)serialization practices followed in this file.
  
      TODO(b/118939620): This is a private method until consensus is reached on
      supporting object deserialization deduping within Keras.
  
      Args:
        config: A Dict config acquired with `_get_config`.
        custom_objects: Optional dictionary mapping names (strings) to custom
          classes or functions to be considered during deserialization.
        columns_by_name: A Dict[String, FeatureColumn] of existing columns in
          order to avoid duplication. Should be passed to any calls to
          deserialize_feature_column().
  
      Returns:
        A FeatureColumn for the input config.
      """
      pass
  
  
  class DenseColumn(FeatureColumn):
    """Represents a column which can be represented as `Tensor`.
  
    Some examples of this type are: numeric_column, embedding_column,
    indicator_column.
    """
  
    @abc.abstractproperty
    def variable_shape(self):
      """`TensorShape` of `get_dense_tensor`, without batch dimension."""
      pass
  
    @abc.abstractmethod
    def get_dense_tensor(self, transformation_cache, state_manager):
      """Returns a `Tensor`.
  
      The output of this function will be used by model-builder-functions. For
      example the pseudo code of `input_layer` will be like:
  
      ```python
      def input_layer(features, feature_columns, ...):
        outputs = [fc.get_dense_tensor(...) for fc in feature_columns]
        return tf.concat(outputs)
      ```
  
      Args:
        transformation_cache: A `FeatureTransformationCache` object to access
          features.
        state_manager: A `StateManager` to create / access resources such as
          lookup tables.
  
      Returns:
        `Tensor` of shape [batch_size] + `variable_shape`.
      """
      pass
  
  
  def is_feature_column_v2(feature_columns):
    """Returns True if all feature columns are V2."""
    for feature_column in feature_columns:
      if not isinstance(feature_column, FeatureColumn):
        return False
      if not feature_column._is_v2_column:  # pylint: disable=protected-access
        return False
    return True
  
  
  def _create_weighted_sum(column, transformation_cache, state_manager,
                           sparse_combiner, weight_var):
    """Creates a weighted sum for a dense/categorical column for linear_model."""
    if isinstance(column, CategoricalColumn):
      return _create_categorical_column_weighted_sum(
          column=column,
          transformation_cache=transformation_cache,
          state_manager=state_manager,
          sparse_combiner=sparse_combiner,
          weight_var=weight_var)
    else:
      return _create_dense_column_weighted_sum(
          column=column,
          transformation_cache=transformation_cache,
          state_manager=state_manager,
          weight_var=weight_var)
  
  
  def _create_dense_column_weighted_sum(column, transformation_cache,
                                        state_manager, weight_var):
    """Create a weighted sum of a dense column for linear_model."""
    tensor = column.get_dense_tensor(transformation_cache, state_manager)
    num_elements = column.variable_shape.num_elements()
    batch_size = array_ops.shape(tensor)[0]
    tensor = array_ops.reshape(tensor, shape=(batch_size, num_elements))
    return math_ops.matmul(tensor, weight_var, name='weighted_sum')
  
  
  class CategoricalColumn(FeatureColumn):
    """Represents a categorical feature.
  
    A categorical feature typically handled with a `tf.SparseTensor` of IDs.
    """
  
    IdWeightPair = collections.namedtuple(  # pylint: disable=invalid-name
        'IdWeightPair', ('id_tensor', 'weight_tensor'))
  
    @abc.abstractproperty
    def num_buckets(self):
      """Returns number of buckets in this sparse feature."""
      pass
  
    @abc.abstractmethod
    def get_sparse_tensors(self, transformation_cache, state_manager):
      """Returns an IdWeightPair.
  
      `IdWeightPair` is a pair of `SparseTensor`s which represents ids and
      weights.
  
      `IdWeightPair.id_tensor` is typically a `batch_size` x `num_buckets`
      `SparseTensor` of `int64`. `IdWeightPair.weight_tensor` is either a
      `SparseTensor` of `float` or `None` to indicate all weights should be
      taken to be 1. If specified, `weight_tensor` must have exactly the same
      shape and indices as `sp_ids`. Expected `SparseTensor` is same as parsing
      output of a `VarLenFeature` which is a ragged matrix.
  
      Args:
        transformation_cache: A `FeatureTransformationCache` object to access
          features.
        state_manager: A `StateManager` to create / access resources such as
          lookup tables.
      """
      pass
  
  
  def _create_categorical_column_weighted_sum(
      column, transformation_cache, state_manager, sparse_combiner, weight_var):
    # pylint: disable=g-doc-return-or-yield,g-doc-args
    """Create a weighted sum of a categorical column for linear_model.
  
    Note to maintainer: As implementation details, the weighted sum is
    implemented via embedding_lookup_sparse toward efficiency. Mathematically,
    they are the same.
  
    To be specific, conceptually, categorical column can be treated as multi-hot
    vector. Say:
  
    ```python
      x = [0 0 1]  # categorical column input
      w = [a b c]  # weights
    ```
    The weighted sum is `c` in this case, which is same as `w[2]`.
  
    Another example is
  
    ```python
      x = [0 1 1]  # categorical column input
      w = [a b c]  # weights
    ```
    The weighted sum is `b + c` in this case, which is same as `w[2] + w[3]`.
  
    For both cases, we can implement weighted sum via embedding_lookup with
    sparse_combiner = "sum".
    """
  
    sparse_tensors = column.get_sparse_tensors(transformation_cache,
                                               state_manager)
    id_tensor = sparse_ops.sparse_reshape(sparse_tensors.id_tensor, [
        array_ops.shape(sparse_tensors.id_tensor)[0], -1
    ])
    weight_tensor = sparse_tensors.weight_tensor
    if weight_tensor is not None:
      weight_tensor = sparse_ops.sparse_reshape(
          weight_tensor, [array_ops.shape(weight_tensor)[0], -1])
  
    return embedding_ops.safe_embedding_lookup_sparse(
        weight_var,
        id_tensor,
        sparse_weights=weight_tensor,
        combiner=sparse_combiner,
        name='weighted_sum')
  
  
  class SequenceDenseColumn(FeatureColumn):
    """Represents dense sequence data."""
  
    TensorSequenceLengthPair = collections.namedtuple(  # pylint: disable=invalid-name
        'TensorSequenceLengthPair', ('dense_tensor', 'sequence_length'))
  
    @abc.abstractmethod
    def get_sequence_dense_tensor(self, transformation_cache, state_manager):
      """Returns a `TensorSequenceLengthPair`.
  
      Args:
        transformation_cache: A `FeatureTransformationCache` object to access
          features.
        state_manager: A `StateManager` to create / access resources such as
          lookup tables.
      """
      pass
  
  
  class FeatureTransformationCache(object):
    """Handles caching of transformations while building the model.
  
    `FeatureColumn` specifies how to digest an input column to the network. Some
    feature columns require data transformations. This class caches those
    transformations.
  
    Some features may be used in more than one place. For example, one can use a
    bucketized feature by itself and a cross with it. In that case we
    should create only one bucketization op instead of creating ops for each
    feature column separately. To handle re-use of transformed columns,
    `FeatureTransformationCache` caches all previously transformed columns.
  
    Example:
    We're trying to use the following `FeatureColumn`s:
  
    ```python
    bucketized_age = fc.bucketized_column(fc.numeric_column("age"), ...)
    keywords = fc.categorical_column_with_hash_buckets("keywords", ...)
    age_X_keywords = fc.crossed_column([bucketized_age, "keywords"])
    ... = linear_model(features,
                            [bucketized_age, keywords, age_X_keywords]
    ```
  
    If we transform each column independently, then we'll get duplication of
    bucketization (one for cross, one for bucketization itself).
    The `FeatureTransformationCache` eliminates this duplication.
    """
  
    def __init__(self, features):
      """Creates a `FeatureTransformationCache`.
  
      Args:
        features: A mapping from feature column to objects that are `Tensor` or
          `SparseTensor`, or can be converted to same via
          `sparse_tensor.convert_to_tensor_or_sparse_tensor`. A `string` key
          signifies a base feature (not-transformed). A `FeatureColumn` key
          means that this `Tensor` is the output of an existing `FeatureColumn`
          which can be reused.
      """
      self._features = features.copy()
      self._feature_tensors = {}
  
    def get(self, key, state_manager):
      """Returns a `Tensor` for the given key.
  
      A `str` key is used to access a base feature (not-transformed). When a
      `FeatureColumn` is passed, the transformed feature is returned if it
      already exists, otherwise the given `FeatureColumn` is asked to provide its
      transformed output, which is then cached.
  
      Args:
        key: a `str` or a `FeatureColumn`.
        state_manager: A StateManager object that holds the FeatureColumn state.
  
      Returns:
        The transformed `Tensor` corresponding to the `key`.
  
      Raises:
        ValueError: if key is not found or a transformed `Tensor` cannot be
          computed.
      """
      if key in self._feature_tensors:
        # FeatureColumn is already transformed or converted.
        return self._feature_tensors[key]
  
      if key in self._features:
        feature_tensor = self._get_raw_feature_as_tensor(key)
        self._feature_tensors[key] = feature_tensor
        return feature_tensor
  
      if isinstance(key, six.string_types):
        raise ValueError('Feature {} is not in features dictionary.'.format(key))
  
      if not isinstance(key, FeatureColumn):
        raise TypeError('"key" must be either a "str" or "FeatureColumn". '
                        'Provided: {}'.format(key))
  
      column = key
      logging.debug('Transforming feature_column %s.', column)
      transformed = column.transform_feature(self, state_manager)
      if transformed is None:
        raise ValueError('Column {} is not supported.'.format(column.name))
      self._feature_tensors[column] = transformed
      return transformed
  
    def _get_raw_feature_as_tensor(self, key):
      """Gets the raw_feature (keyed by `key`) as `tensor`.
  
      The raw feature is converted to (sparse) tensor and maybe expand dim.
  
      For both `Tensor` and `SparseTensor`, the rank will be expanded (to 2) if
      the rank is 1. This supports dynamic rank also. For rank 0 raw feature, will
      error out as it is not supported.
  
      Args:
        key: A `str` key to access the raw feature.
  
      Returns:
        A `Tensor` or `SparseTensor`.
  
      Raises:
        ValueError: if the raw feature has rank 0.
      """
      raw_feature = self._features[key]
      feature_tensor = sparse_tensor_lib.convert_to_tensor_or_sparse_tensor(
          raw_feature)
  
      def expand_dims(input_tensor):
        # Input_tensor must have rank 1.
        if isinstance(input_tensor, sparse_tensor_lib.SparseTensor):
          return sparse_ops.sparse_reshape(
              input_tensor, [array_ops.shape(input_tensor)[0], 1])
        else:
          return array_ops.expand_dims(input_tensor, -1)
  
      rank = feature_tensor.get_shape().ndims
      if rank is not None:
        if rank == 0:
          raise ValueError(
              'Feature (key: {}) cannot have rank 0. Give: {}'.format(
                  key, feature_tensor))
        return feature_tensor if rank != 1 else expand_dims(feature_tensor)
  
      # Handle dynamic rank.
      with ops.control_dependencies([
          check_ops.assert_positive(
              array_ops.rank(feature_tensor),
              message='Feature (key: {}) cannot have rank 0. Given: {}'.format(
                  key, feature_tensor))]):
        return control_flow_ops.cond(
            math_ops.equal(1, array_ops.rank(feature_tensor)),
            lambda: expand_dims(feature_tensor),
            lambda: feature_tensor)
  
  
  # TODO(ptucker): Move to third_party/tensorflow/python/ops/sparse_ops.py
  def _to_sparse_input_and_drop_ignore_values(input_tensor, ignore_value=None):
    """Converts a `Tensor` to a `SparseTensor`, dropping ignore_value cells.
  
    If `input_tensor` is already a `SparseTensor`, just return it.
  
    Args:
      input_tensor: A string or integer `Tensor`.
      ignore_value: Entries in `dense_tensor` equal to this value will be
        absent from the resulting `SparseTensor`. If `None`, default value of
        `dense_tensor`'s dtype will be used ('' for `str`, -1 for `int`).
  
    Returns:
      A `SparseTensor` with the same shape as `input_tensor`.
  
    Raises:
      ValueError: when `input_tensor`'s rank is `None`.
    """
    input_tensor = sparse_tensor_lib.convert_to_tensor_or_sparse_tensor(
        input_tensor)
    if isinstance(input_tensor, sparse_tensor_lib.SparseTensor):
      return input_tensor
    with ops.name_scope(None, 'to_sparse_input', (input_tensor, ignore_value,)):
      if ignore_value is None:
        if input_tensor.dtype == dtypes.string:
          # Exception due to TF strings are converted to numpy objects by default.
          ignore_value = ''
        elif input_tensor.dtype.is_integer:
          ignore_value = -1  # -1 has a special meaning of missing feature
        else:
          # NOTE: `as_numpy_dtype` is a property, so with the parentheses this is
          # constructing a new numpy object of the given type, which yields the
          # default value for that type.
          ignore_value = input_tensor.dtype.as_numpy_dtype()
      ignore_value = math_ops.cast(
          ignore_value, input_tensor.dtype, name='ignore_value')
      indices = array_ops.where_v2(
          math_ops.not_equal(input_tensor, ignore_value), name='indices')
      return sparse_tensor_lib.SparseTensor(
          indices=indices,
          values=array_ops.gather_nd(input_tensor, indices, name='values'),
          dense_shape=array_ops.shape(
              input_tensor, out_type=dtypes.int64, name='dense_shape'))
  
  
  def _normalize_feature_columns(feature_columns):
    """Normalizes the `feature_columns` input.
  
    This method converts the `feature_columns` to list type as best as it can. In
    addition, verifies the type and other parts of feature_columns, required by
    downstream library.
  
    Args:
      feature_columns: The raw feature columns, usually passed by users.
  
    Returns:
      The normalized feature column list.
  
    Raises:
      ValueError: for any invalid inputs, such as empty, duplicated names, etc.
    """
    if isinstance(feature_columns, FeatureColumn):
      feature_columns = [feature_columns]
  
    if isinstance(feature_columns, collections_abc.Iterator):
      feature_columns = list(feature_columns)
  
    if isinstance(feature_columns, dict):
      raise ValueError('Expected feature_columns to be iterable, found dict.')
  
    for column in feature_columns:
      if not isinstance(column, FeatureColumn):
        raise ValueError('Items of feature_columns must be a FeatureColumn. '
                         'Given (type {}): {}.'.format(type(column), column))
    if not feature_columns:
      raise ValueError('feature_columns must not be empty.')
    name_to_column = {}
    for column in feature_columns:
      if column.name in name_to_column:
        raise ValueError('Duplicate feature column name found for columns: {} '
                         'and {}. This usually means that these columns refer to '
                         'same base feature. Either one must be discarded or a '
                         'duplicated but renamed item must be inserted in '
                         'features dict.'.format(column,
                                                 name_to_column[column.name]))
      name_to_column[column.name] = column
  
    return sorted(feature_columns, key=lambda x: x.name)
  
  
  class NumericColumn(
      DenseColumn,
      fc_old._DenseColumn,  # pylint: disable=protected-access
      collections.namedtuple(
          'NumericColumn',
          ('key', 'shape', 'default_value', 'dtype', 'normalizer_fn'))):
    """see `numeric_column`."""
  
    @property
    def _is_v2_column(self):
      return True
  
    @property
    def name(self):
      """See `FeatureColumn` base class."""
      return self.key
  
    @property
    def parse_example_spec(self):
      """See `FeatureColumn` base class."""
      return {
          self.key:
              parsing_ops.FixedLenFeature(self.shape, self.dtype,
                                          self.default_value)
      }
  
    @property
    @deprecation.deprecated(_FEATURE_COLUMN_DEPRECATION_DATE,
                            _FEATURE_COLUMN_DEPRECATION)
    def _parse_example_spec(self):
      return self.parse_example_spec
  
    def _transform_input_tensor(self, input_tensor):
      if isinstance(input_tensor, sparse_tensor_lib.SparseTensor):
        raise ValueError(
            'The corresponding Tensor of numerical column must be a Tensor. '
            'SparseTensor is not supported. key: {}'.format(self.key))
      if self.normalizer_fn is not None:
        input_tensor = self.normalizer_fn(input_tensor)
      return math_ops.cast(input_tensor, dtypes.float32)
  
    @deprecation.deprecated(_FEATURE_COLUMN_DEPRECATION_DATE,
                            _FEATURE_COLUMN_DEPRECATION)
    def _transform_feature(self, inputs):
      input_tensor = inputs.get(self.key)
      return self._transform_input_tensor(input_tensor)
  
    def transform_feature(self, transformation_cache, state_manager):
      """See `FeatureColumn` base class.
  
      In this case, we apply the `normalizer_fn` to the input tensor.
  
      Args:
        transformation_cache: A `FeatureTransformationCache` object to access
          features.
        state_manager: A `StateManager` to create / access resources such as
          lookup tables.
  
      Returns:
        Normalized input tensor.
      Raises:
        ValueError: If a SparseTensor is passed in.
      """
      input_tensor = transformation_cache.get(self.key, state_manager)
      return self._transform_input_tensor(input_tensor)
  
    @property
    def variable_shape(self):
      """See `DenseColumn` base class."""
      return tensor_shape.TensorShape(self.shape)
  
    @property
    @deprecation.deprecated(_FEATURE_COLUMN_DEPRECATION_DATE,
                            _FEATURE_COLUMN_DEPRECATION)
    def _variable_shape(self):
      return self.variable_shape
  
    def get_dense_tensor(self, transformation_cache, state_manager):
      """Returns dense `Tensor` representing numeric feature.
  
      Args:
        transformation_cache: A `FeatureTransformationCache` object to access
          features.
        state_manager: A `StateManager` to create / access resources such as
          lookup tables.
  
      Returns:
        Dense `Tensor` created within `transform_feature`.
      """
      # Feature has been already transformed. Return the intermediate
      # representation created by _transform_feature.
      return transformation_cache.get(self, state_manager)
  
    @deprecation.deprecated(_FEATURE_COLUMN_DEPRECATION_DATE,
                            _FEATURE_COLUMN_DEPRECATION)
    def _get_dense_tensor(self, inputs, weight_collections=None, trainable=None):
      del weight_collections
      del trainable
      return inputs.get(self)
  
    @property
    def parents(self):
      """See 'FeatureColumn` base class."""
      return [self.key]
  
    def _get_config(self):
      """See 'FeatureColumn` base class."""
      config = dict(zip(self._fields, self))
      config['normalizer_fn'] = generic_utils.serialize_keras_object(
          self.normalizer_fn)
      config['dtype'] = self.dtype.name
      return config
  
    @classmethod
    def _from_config(cls, config, custom_objects=None, columns_by_name=None):
      """See 'FeatureColumn` base class."""
      _check_config_keys(config, cls._fields)
      kwargs = _standardize_and_copy_config(config)
      kwargs['normalizer_fn'] = generic_utils.deserialize_keras_object(
          config['normalizer_fn'], custom_objects=custom_objects)
      kwargs['dtype'] = dtypes.as_dtype(config['dtype'])
  
      return cls(**kwargs)
  
  
  class BucketizedColumn(
      DenseColumn,
      CategoricalColumn,
      fc_old._DenseColumn,  # pylint: disable=protected-access
      fc_old._CategoricalColumn,  # pylint: disable=protected-access
      collections.namedtuple('BucketizedColumn',
                             ('source_column', 'boundaries'))):
    """See `bucketized_column`."""
  
    @property
    def _is_v2_column(self):
      return (isinstance(self.source_column, FeatureColumn) and
              self.source_column._is_v2_column)  # pylint: disable=protected-access
  
    @property
    def name(self):
      """See `FeatureColumn` base class."""
      return '{}_bucketized'.format(self.source_column.name)
  
    @property
    def parse_example_spec(self):
      """See `FeatureColumn` base class."""
      return self.source_column.parse_example_spec
  
    @property
    @deprecation.deprecated(_FEATURE_COLUMN_DEPRECATION_DATE,
                            _FEATURE_COLUMN_DEPRECATION)
    def _parse_example_spec(self):
      return self.source_column._parse_example_spec  # pylint: disable=protected-access
  
    @deprecation.deprecated(_FEATURE_COLUMN_DEPRECATION_DATE,
                            _FEATURE_COLUMN_DEPRECATION)
    def _transform_feature(self, inputs):
      """Returns bucketized categorical `source_column` tensor."""
      source_tensor = inputs.get(self.source_column)
      return math_ops._bucketize(  # pylint: disable=protected-access
          source_tensor,
          boundaries=self.boundaries)
  
    def transform_feature(self, transformation_cache, state_manager):
      """Returns bucketized categorical `source_column` tensor."""
      source_tensor = transformation_cache.get(self.source_column, state_manager)
      return math_ops._bucketize(  # pylint: disable=protected-access
          source_tensor,
          boundaries=self.boundaries)
  
    @property
    def variable_shape(self):
      """See `DenseColumn` base class."""
      return tensor_shape.TensorShape(
          tuple(self.source_column.shape) + (len(self.boundaries) + 1,))
  
    @property
    @deprecation.deprecated(_FEATURE_COLUMN_DEPRECATION_DATE,
                            _FEATURE_COLUMN_DEPRECATION)
    def _variable_shape(self):
      return self.variable_shape
  
    def _get_dense_tensor_for_input_tensor(self, input_tensor):
      return array_ops.one_hot(
          indices=math_ops.cast(input_tensor, dtypes.int64),
          depth=len(self.boundaries) + 1,
          on_value=1.,
          off_value=0.)
  
    def get_dense_tensor(self, transformation_cache, state_manager):
      """Returns one hot encoded dense `Tensor`."""
      input_tensor = transformation_cache.get(self, state_manager)
      return self._get_dense_tensor_for_input_tensor(input_tensor)
  
    @deprecation.deprecated(_FEATURE_COLUMN_DEPRECATION_DATE,
                            _FEATURE_COLUMN_DEPRECATION)
    def _get_dense_tensor(self, inputs, weight_collections=None, trainable=None):
      del weight_collections
      del trainable
      input_tensor = inputs.get(self)
      return self._get_dense_tensor_for_input_tensor(input_tensor)
  
    @property
    def num_buckets(self):
      """See `CategoricalColumn` base class."""
      # By construction, source_column is always one-dimensional.
      return (len(self.boundaries) + 1) * self.source_column.shape[0]
  
    @property
    @deprecation.deprecated(_FEATURE_COLUMN_DEPRECATION_DATE,
                            _FEATURE_COLUMN_DEPRECATION)
    def _num_buckets(self):
      return self.num_buckets
  
    def _get_sparse_tensors_for_input_tensor(self, input_tensor):
      batch_size = array_ops.shape(input_tensor)[0]
      # By construction, source_column is always one-dimensional.
      source_dimension = self.source_column.shape[0]
  
      i1 = array_ops.reshape(
          array_ops.tile(
              array_ops.expand_dims(math_ops.range(0, batch_size), 1),
              [1, source_dimension]),
          (-1,))
      i2 = array_ops.tile(math_ops.range(0, source_dimension), [batch_size])
      # Flatten the bucket indices and unique them across dimensions
      # E.g. 2nd dimension indices will range from k to 2*k-1 with k buckets
      bucket_indices = (
          array_ops.reshape(input_tensor, (-1,)) +
          (len(self.boundaries) + 1) * i2)
  
      indices = math_ops.cast(
          array_ops.transpose(array_ops.stack((i1, i2))), dtypes.int64)
      dense_shape = math_ops.cast(
          array_ops.stack([batch_size, source_dimension]), dtypes.int64)
      sparse_tensor = sparse_tensor_lib.SparseTensor(
          indices=indices,
          values=bucket_indices,
          dense_shape=dense_shape)
      return CategoricalColumn.IdWeightPair(sparse_tensor, None)
  
    def get_sparse_tensors(self, transformation_cache, state_manager):
      """Converts dense inputs to SparseTensor so downstream code can use it."""
      input_tensor = transformation_cache.get(self, state_manager)
      return self._get_sparse_tensors_for_input_tensor(input_tensor)
  
    @deprecation.deprecated(_FEATURE_COLUMN_DEPRECATION_DATE,
                            _FEATURE_COLUMN_DEPRECATION)
    def _get_sparse_tensors(self, inputs, weight_collections=None,
                            trainable=None):
      """Converts dense inputs to SparseTensor so downstream code can use it."""
      del weight_collections
      del trainable
      input_tensor = inputs.get(self)
      return self._get_sparse_tensors_for_input_tensor(input_tensor)
  
    @property
    def parents(self):
      """See 'FeatureColumn` base class."""
      return [self.source_column]
  
    def _get_config(self):
      """See 'FeatureColumn` base class."""
      from tensorflow.python.feature_column.serialization import serialize_feature_column  # pylint: disable=g-import-not-at-top
      config = dict(zip(self._fields, self))
      config['source_column'] = serialize_feature_column(self.source_column)
      return config
  
    @classmethod
    def _from_config(cls, config, custom_objects=None, columns_by_name=None):
      """See 'FeatureColumn` base class."""
      from tensorflow.python.feature_column.serialization import deserialize_feature_column  # pylint: disable=g-import-not-at-top
      _check_config_keys(config, cls._fields)
      kwargs = _standardize_and_copy_config(config)
      kwargs['source_column'] = deserialize_feature_column(
          config['source_column'], custom_objects, columns_by_name)
      return cls(**kwargs)
  
  
  class EmbeddingColumn(
      DenseColumn,
      SequenceDenseColumn,
      fc_old._DenseColumn,  # pylint: disable=protected-access
      fc_old._SequenceDenseColumn,  # pylint: disable=protected-access
      collections.namedtuple(
          'EmbeddingColumn',
          ('categorical_column', 'dimension', 'combiner', 'initializer',
           'ckpt_to_load_from', 'tensor_name_in_ckpt', 'max_norm', 'trainable'))):
    """See `embedding_column`."""
  
    @property
    def _is_v2_column(self):
      return (isinstance(self.categorical_column, FeatureColumn) and
              self.categorical_column._is_v2_column)  # pylint: disable=protected-access
  
    @property
    def name(self):
      """See `FeatureColumn` base class."""
      return '{}_embedding'.format(self.categorical_column.name)
  
    @property
    def parse_example_spec(self):
      """See `FeatureColumn` base class."""
      return self.categorical_column.parse_example_spec
  
    @property
    @deprecation.deprecated(_FEATURE_COLUMN_DEPRECATION_DATE,
                            _FEATURE_COLUMN_DEPRECATION)
    def _parse_example_spec(self):
      return self.categorical_column._parse_example_spec  # pylint: disable=protected-access
  
    def transform_feature(self, transformation_cache, state_manager):
      """Transforms underlying `categorical_column`."""
      return transformation_cache.get(self.categorical_column, state_manager)
  
    @deprecation.deprecated(_FEATURE_COLUMN_DEPRECATION_DATE,
                            _FEATURE_COLUMN_DEPRECATION)
    def _transform_feature(self, inputs):
      return inputs.get(self.categorical_column)
  
    @property
    def variable_shape(self):
      """See `DenseColumn` base class."""
      return tensor_shape.TensorShape([self.dimension])
  
    @property
    @deprecation.deprecated(_FEATURE_COLUMN_DEPRECATION_DATE,
                            _FEATURE_COLUMN_DEPRECATION)
    def _variable_shape(self):
      return self.variable_shape
  
    def create_state(self, state_manager):
      """Creates the embedding lookup variable."""
      num_buckets = getattr(self.categorical_column, 'num_buckets',
                            self.categorical_column._num_buckets)  # pylint: disable=protected-access
      embedding_shape = (num_buckets, self.dimension)
      state_manager.create_variable(
          self,
          name='embedding_weights',
          shape=embedding_shape,
          dtype=dtypes.float32,
          trainable=self.trainable,
          use_resource=True,
          initializer=self.initializer)
  
    def _get_dense_tensor_internal_helper(self, sparse_tensors,
                                          embedding_weights):
      sparse_ids = sparse_tensors.id_tensor
      sparse_weights = sparse_tensors.weight_tensor
  
      if self.ckpt_to_load_from is not None:
        to_restore = embedding_weights
        if isinstance(to_restore, variables.PartitionedVariable):
          to_restore = to_restore._get_variable_list()  # pylint: disable=protected-access
        checkpoint_utils.init_from_checkpoint(self.ckpt_to_load_from, {
            self.tensor_name_in_ckpt: to_restore
        })
  
      # Return embedding lookup result.
      return embedding_ops.safe_embedding_lookup_sparse(
          embedding_weights=embedding_weights,
          sparse_ids=sparse_ids,
          sparse_weights=sparse_weights,
          combiner=self.combiner,
          name='%s_weights' % self.name,
          max_norm=self.max_norm)
  
    def _get_dense_tensor_internal(self, sparse_tensors, state_manager):
      """Private method that follows the signature of get_dense_tensor."""
      embedding_weights = state_manager.get_variable(
          self, name='embedding_weights')
      return self._get_dense_tensor_internal_helper(sparse_tensors,
                                                    embedding_weights)
  
    def _old_get_dense_tensor_internal(self, sparse_tensors, weight_collections,
                                       trainable):
      """Private method that follows the signature of _get_dense_tensor."""
      embedding_shape = (self.categorical_column._num_buckets, self.dimension)  # pylint: disable=protected-access
      if (weight_collections and
          ops.GraphKeys.GLOBAL_VARIABLES not in weight_collections):
        weight_collections.append(ops.GraphKeys.GLOBAL_VARIABLES)
      embedding_weights = variable_scope.get_variable(
          name='embedding_weights',
          shape=embedding_shape,
          dtype=dtypes.float32,
          initializer=self.initializer,
          trainable=self.trainable and trainable,
          collections=weight_collections)
      return self._get_dense_tensor_internal_helper(sparse_tensors,
                                                    embedding_weights)
  
    def get_dense_tensor(self, transformation_cache, state_manager):
      """Returns tensor after doing the embedding lookup.
  
      Args:
        transformation_cache: A `FeatureTransformationCache` object to access
          features.
        state_manager: A `StateManager` to create / access resources such as
          lookup tables.
  
      Returns:
        Embedding lookup tensor.
  
      Raises:
        ValueError: `categorical_column` is SequenceCategoricalColumn.
      """
      if isinstance(self.categorical_column, SequenceCategoricalColumn):
        raise ValueError(
            'In embedding_column: {}. '
            'categorical_column must not be of type SequenceCategoricalColumn. '
            'Suggested fix A: If you wish to use DenseFeatures, use a '
            'non-sequence categorical_column_with_*. '
            'Suggested fix B: If you wish to create sequence input, use '
            'SequenceFeatures instead of DenseFeatures. '
            'Given (type {}): {}'.format(self.name, type(self.categorical_column),
                                         self.categorical_column))
      # Get sparse IDs and weights.
      sparse_tensors = self.categorical_column.get_sparse_tensors(
          transformation_cache, state_manager)
      return self._get_dense_tensor_internal(sparse_tensors, state_manager)
  
    @deprecation.deprecated(_FEATURE_COLUMN_DEPRECATION_DATE,
                            _FEATURE_COLUMN_DEPRECATION)
    def _get_dense_tensor(self, inputs, weight_collections=None, trainable=None):
      if isinstance(
          self.categorical_column,
          (SequenceCategoricalColumn, fc_old._SequenceCategoricalColumn)):  # pylint: disable=protected-access
        raise ValueError(
            'In embedding_column: {}. '
            'categorical_column must not be of type _SequenceCategoricalColumn. '
            'Suggested fix A: If you wish to use DenseFeatures, use a '
            'non-sequence categorical_column_with_*. '
            'Suggested fix B: If you wish to create sequence input, use '
            'SequenceFeatures instead of DenseFeatures. '
            'Given (type {}): {}'.format(self.name, type(self.categorical_column),
                                         self.categorical_column))
      sparse_tensors = self.categorical_column._get_sparse_tensors(  # pylint: disable=protected-access
          inputs, weight_collections, trainable)
      return self._old_get_dense_tensor_internal(sparse_tensors,
                                                 weight_collections, trainable)
  
    def get_sequence_dense_tensor(self, transformation_cache, state_manager):
      """See `SequenceDenseColumn` base class."""
      if not isinstance(self.categorical_column, SequenceCategoricalColumn):
        raise ValueError(
            'In embedding_column: {}. '
            'categorical_column must be of type SequenceCategoricalColumn '
            'to use SequenceFeatures. '
            'Suggested fix: Use one of sequence_categorical_column_with_*. '
            'Given (type {}): {}'.format(self.name, type(self.categorical_column),
                                         self.categorical_column))
      sparse_tensors = self.categorical_column.get_sparse_tensors(
          transformation_cache, state_manager)
      dense_tensor = self._get_dense_tensor_internal(sparse_tensors,
                                                     state_manager)
      sequence_length = fc_utils.sequence_length_from_sparse_tensor(
          sparse_tensors.id_tensor)
      return SequenceDenseColumn.TensorSequenceLengthPair(
          dense_tensor=dense_tensor, sequence_length=sequence_length)
  
    @deprecation.deprecated(_FEATURE_COLUMN_DEPRECATION_DATE,
                            _FEATURE_COLUMN_DEPRECATION)
    def _get_sequence_dense_tensor(self,
                                   inputs,
                                   weight_collections=None,
                                   trainable=None):
      if not isinstance(
          self.categorical_column,
          (SequenceCategoricalColumn, fc_old._SequenceCategoricalColumn)):  # pylint: disable=protected-access
        raise ValueError(
            'In embedding_column: {}. '
            'categorical_column must be of type SequenceCategoricalColumn '
            'to use SequenceFeatures. '
            'Suggested fix: Use one of sequence_categorical_column_with_*. '
            'Given (type {}): {}'.format(self.name, type(self.categorical_column),
                                         self.categorical_column))
      sparse_tensors = self.categorical_column._get_sparse_tensors(inputs)  # pylint: disable=protected-access
      dense_tensor = self._old_get_dense_tensor_internal(
          sparse_tensors,
          weight_collections=weight_collections,
          trainable=trainable)
      sequence_length = fc_utils.sequence_length_from_sparse_tensor(
          sparse_tensors.id_tensor)
      return SequenceDenseColumn.TensorSequenceLengthPair(
          dense_tensor=dense_tensor, sequence_length=sequence_length)
  
    @property
    def parents(self):
      """See 'FeatureColumn` base class."""
      return [self.categorical_column]
  
    def _get_config(self):
      """See 'FeatureColumn` base class."""
      from tensorflow.python.feature_column.serialization import serialize_feature_column  # pylint: disable=g-import-not-at-top
      config = dict(zip(self._fields, self))
      config['categorical_column'] = serialize_feature_column(
          self.categorical_column)
      config['initializer'] = initializers.serialize(self.initializer)
      return config
  
    @classmethod
    def _from_config(cls, config, custom_objects=None, columns_by_name=None):
      """See 'FeatureColumn` base class."""
      from tensorflow.python.feature_column.serialization import deserialize_feature_column  # pylint: disable=g-import-not-at-top
      _check_config_keys(config, cls._fields)
      kwargs = _standardize_and_copy_config(config)
      kwargs['categorical_column'] = deserialize_feature_column(
          config['categorical_column'], custom_objects, columns_by_name)
      kwargs['initializer'] = initializers.deserialize(
          config['initializer'], custom_objects=custom_objects)
      return cls(**kwargs)
  
  
  def _raise_shared_embedding_column_error():
    raise ValueError('SharedEmbeddingColumns are not supported in '
                     '`linear_model` or `input_layer`. Please use '
                     '`DenseFeatures` or `LinearModel` instead.')
  
  
  class SharedEmbeddingColumnCreator(tracking.AutoTrackable):
  
    def __init__(self,
                 dimension,
                 initializer,
                 ckpt_to_load_from,
                 tensor_name_in_ckpt,
                 num_buckets,
                 trainable,
                 name='shared_embedding_column_creator'):
      self._dimension = dimension
      self._initializer = initializer
      self._ckpt_to_load_from = ckpt_to_load_from
      self._tensor_name_in_ckpt = tensor_name_in_ckpt
      self._num_buckets = num_buckets
      self._trainable = trainable
      self._name = name
      # Map from graph keys to embedding_weight variables.
      self._embedding_weights = {}
  
    def __call__(self, categorical_column, combiner, max_norm):
      return SharedEmbeddingColumn(categorical_column, self, combiner, max_norm)
  
    @property
    def embedding_weights(self):
      key = ops.get_default_graph()._graph_key  # pylint: disable=protected-access
      if key not in self._embedding_weights:
        embedding_shape = (self._num_buckets, self._dimension)
        var = variable_scope.get_variable(
            name=self._name,
            shape=embedding_shape,
            dtype=dtypes.float32,
            initializer=self._initializer,
            trainable=self._trainable)
  
        if self._ckpt_to_load_from is not None:
          to_restore = var
          if isinstance(to_restore, variables.PartitionedVariable):
            to_restore = to_restore._get_variable_list()  # pylint: disable=protected-access
          checkpoint_utils.init_from_checkpoint(
              self._ckpt_to_load_from, {self._tensor_name_in_ckpt: to_restore})
        self._embedding_weights[key] = var
      return self._embedding_weights[key]
  
    @property
    def dimension(self):
      return self._dimension
  
  
  class SharedEmbeddingColumn(
      DenseColumn,
      SequenceDenseColumn,
      fc_old._DenseColumn,  # pylint: disable=protected-access
      fc_old._SequenceDenseColumn,  # pylint: disable=protected-access
      collections.namedtuple(
          'SharedEmbeddingColumn',
          ('categorical_column', 'shared_embedding_column_creator', 'combiner',
           'max_norm'))):
    """See `embedding_column`."""
  
    @property
    def _is_v2_column(self):
      return True
  
    @property
    def name(self):
      """See `FeatureColumn` base class."""
      return '{}_shared_embedding'.format(self.categorical_column.name)
  
    @property
    def parse_example_spec(self):
      """See `FeatureColumn` base class."""
      return self.categorical_column.parse_example_spec
  
    @property
    def _parse_example_spec(self):
      return _raise_shared_embedding_column_error()
  
    def transform_feature(self, transformation_cache, state_manager):
      """See `FeatureColumn` base class."""
      return transformation_cache.get(self.categorical_column, state_manager)
  
    def _transform_feature(self, inputs):
      return _raise_shared_embedding_column_error()
  
    @property
    def variable_shape(self):
      """See `DenseColumn` base class."""
      return tensor_shape.TensorShape(
          [self.shared_embedding_column_creator.dimension])
  
    @property
    def _variable_shape(self):
      return _raise_shared_embedding_column_error()
  
    def _get_dense_tensor_internal(self, transformation_cache, state_manager):
      """Private method that follows the signature of _get_dense_tensor."""
      # This method is called from a variable_scope with name _var_scope_name,
      # which is shared among all shared embeddings. Open a name_scope here, so
      # that the ops for different columns have distinct names.
      with ops.name_scope(None, default_name=self.name):
        # Get sparse IDs and weights.
        sparse_tensors = self.categorical_column.get_sparse_tensors(
            transformation_cache, state_manager)
        sparse_ids = sparse_tensors.id_tensor
        sparse_weights = sparse_tensors.weight_tensor
  
        embedding_weights = self.shared_embedding_column_creator.embedding_weights
  
        # Return embedding lookup result.
        return embedding_ops.safe_embedding_lookup_sparse(
            embedding_weights=embedding_weights,
            sparse_ids=sparse_ids,
            sparse_weights=sparse_weights,
            combiner=self.combiner,
            name='%s_weights' % self.name,
            max_norm=self.max_norm)
  
    def get_dense_tensor(self, transformation_cache, state_manager):
      """Returns the embedding lookup result."""
      if isinstance(self.categorical_column, SequenceCategoricalColumn):
        raise ValueError(
            'In embedding_column: {}. '
            'categorical_column must not be of type SequenceCategoricalColumn. '
            'Suggested fix A: If you wish to use DenseFeatures, use a '
            'non-sequence categorical_column_with_*. '
            'Suggested fix B: If you wish to create sequence input, use '
            'SequenceFeatures instead of DenseFeatures. '
            'Given (type {}): {}'.format(self.name, type(self.categorical_column),
                                         self.categorical_column))
      return self._get_dense_tensor_internal(transformation_cache, state_manager)
  
    def _get_dense_tensor(self, inputs, weight_collections=None, trainable=None):
      return _raise_shared_embedding_column_error()
  
    def get_sequence_dense_tensor(self, transformation_cache, state_manager):
      """See `SequenceDenseColumn` base class."""
      if not isinstance(self.categorical_column, SequenceCategoricalColumn):
        raise ValueError(
            'In embedding_column: {}. '
            'categorical_column must be of type SequenceCategoricalColumn '
            'to use SequenceFeatures. '
            'Suggested fix: Use one of sequence_categorical_column_with_*. '
            'Given (type {}): {}'.format(self.name, type(self.categorical_column),
                                         self.categorical_column))
      dense_tensor = self._get_dense_tensor_internal(transformation_cache,
                                                     state_manager)
      sparse_tensors = self.categorical_column.get_sparse_tensors(
          transformation_cache, state_manager)
      sequence_length = fc_utils.sequence_length_from_sparse_tensor(
          sparse_tensors.id_tensor)
      return SequenceDenseColumn.TensorSequenceLengthPair(
          dense_tensor=dense_tensor, sequence_length=sequence_length)
  
    def _get_sequence_dense_tensor(self,
                                   inputs,
                                   weight_collections=None,
                                   trainable=None):
      return _raise_shared_embedding_column_error()
  
    @property
    def parents(self):
      """See 'FeatureColumn` base class."""
      return [self.categorical_column]
  
    def _get_config(self):
      """See 'FeatureColumn` base class."""
      raise NotImplementedError()
  
    @classmethod
    def _from_config(cls, config, custom_objects=None, columns_by_name=None):
      """See 'FeatureColumn` base class."""
      raise NotImplementedError()
  
  
  def _check_shape(shape, key):
    """Returns shape if it's valid, raises error otherwise."""
    assert shape is not None
    if not nest.is_sequence(shape):
      shape = [shape]
    shape = tuple(shape)
    for dimension in shape:
      if not isinstance(dimension, int):
        raise TypeError('shape dimensions must be integer. '
                        'shape: {}, key: {}'.format(shape, key))
      if dimension < 1:
        raise ValueError('shape dimensions must be greater than 0. '
                         'shape: {}, key: {}'.format(shape, key))
    return shape
  
  
  class HashedCategoricalColumn(
      CategoricalColumn,
      fc_old._CategoricalColumn,  # pylint: disable=protected-access
      collections.namedtuple('HashedCategoricalColumn',
                             ('key', 'hash_bucket_size', 'dtype'))):
    """see `categorical_column_with_hash_bucket`."""
  
    @property
    def _is_v2_column(self):
      return True
  
    @property
    def name(self):
      """See `FeatureColumn` base class."""
      return self.key
  
    @property
    def parse_example_spec(self):
      """See `FeatureColumn` base class."""
      return {self.key: parsing_ops.VarLenFeature(self.dtype)}
  
    @property
    @deprecation.deprecated(_FEATURE_COLUMN_DEPRECATION_DATE,
                            _FEATURE_COLUMN_DEPRECATION)
    def _parse_example_spec(self):
      return self.parse_example_spec
  
    def _transform_input_tensor(self, input_tensor):
      """Hashes the values in the feature_column."""
      if not isinstance(input_tensor, sparse_tensor_lib.SparseTensor):
        raise ValueError('SparseColumn input must be a SparseTensor.')
  
      fc_utils.assert_string_or_int(
          input_tensor.dtype,
          prefix='column_name: {} input_tensor'.format(self.key))
  
      if self.dtype.is_integer != input_tensor.dtype.is_integer:
        raise ValueError(
            'Column dtype and SparseTensors dtype must be compatible. '
            'key: {}, column dtype: {}, tensor dtype: {}'.format(
                self.key, self.dtype, input_tensor.dtype))
  
      if self.dtype == dtypes.string:
        sparse_values = input_tensor.values
      else:
        sparse_values = string_ops.as_string(input_tensor.values)
  
      sparse_id_values = string_ops.string_to_hash_bucket_fast(
          sparse_values, self.hash_bucket_size, name='lookup')
      return sparse_tensor_lib.SparseTensor(
          input_tensor.indices, sparse_id_values, input_tensor.dense_shape)
  
    def transform_feature(self, transformation_cache, state_manager):
      """Hashes the values in the feature_column."""
      input_tensor = _to_sparse_input_and_drop_ignore_values(
          transformation_cache.get(self.key, state_manager))
      return self._transform_input_tensor(input_tensor)
  
    @deprecation.deprecated(_FEATURE_COLUMN_DEPRECATION_DATE,
                            _FEATURE_COLUMN_DEPRECATION)
    def _transform_feature(self, inputs):
      input_tensor = _to_sparse_input_and_drop_ignore_values(inputs.get(self.key))
      return self._transform_input_tensor(input_tensor)
  
    @property
    def num_buckets(self):
      """Returns number of buckets in this sparse feature."""
      return self.hash_bucket_size
  
    @property
    @deprecation.deprecated(_FEATURE_COLUMN_DEPRECATION_DATE,
                            _FEATURE_COLUMN_DEPRECATION)
    def _num_buckets(self):
      return self.num_buckets
  
    def get_sparse_tensors(self, transformation_cache, state_manager):
      """See `CategoricalColumn` base class."""
      return CategoricalColumn.IdWeightPair(
          transformation_cache.get(self, state_manager), None)
  
    @deprecation.deprecated(_FEATURE_COLUMN_DEPRECATION_DATE,
                            _FEATURE_COLUMN_DEPRECATION)
    def _get_sparse_tensors(self, inputs, weight_collections=None,
                            trainable=None):
      del weight_collections
      del trainable
      return CategoricalColumn.IdWeightPair(inputs.get(self), None)
  
    @property
    def parents(self):
      """See 'FeatureColumn` base class."""
      return [self.key]
  
    def _get_config(self):
      """See 'FeatureColumn` base class."""
      config = dict(zip(self._fields, self))
      config['dtype'] = self.dtype.name
      return config
  
    @classmethod
    def _from_config(cls, config, custom_objects=None, columns_by_name=None):
      """See 'FeatureColumn` base class."""
      _check_config_keys(config, cls._fields)
      kwargs = _standardize_and_copy_config(config)
      kwargs['dtype'] = dtypes.as_dtype(config['dtype'])
      return cls(**kwargs)
  
  
  class VocabularyFileCategoricalColumn(
      CategoricalColumn,
      fc_old._CategoricalColumn,  # pylint: disable=protected-access
      collections.namedtuple('VocabularyFileCategoricalColumn',
                             ('key', 'vocabulary_file', 'vocabulary_size',
                              'num_oov_buckets', 'dtype', 'default_value'))):
    """See `categorical_column_with_vocabulary_file`."""
  
    @property
    def _is_v2_column(self):
      return True
  
    @property
    def name(self):
      """See `FeatureColumn` base class."""
      return self.key
  
    @property
    def parse_example_spec(self):
      """See `FeatureColumn` base class."""
      return {self.key: parsing_ops.VarLenFeature(self.dtype)}
  
    @property
    @deprecation.deprecated(_FEATURE_COLUMN_DEPRECATION_DATE,
                            _FEATURE_COLUMN_DEPRECATION)
    def _parse_example_spec(self):
      return self.parse_example_spec
  
    def _transform_input_tensor(self, input_tensor, state_manager=None):
      """Creates a lookup table for the vocabulary."""
      if self.dtype.is_integer != input_tensor.dtype.is_integer:
        raise ValueError(
            'Column dtype and SparseTensors dtype must be compatible. '
            'key: {}, column dtype: {}, tensor dtype: {}'.format(
                self.key, self.dtype, input_tensor.dtype))
  
      fc_utils.assert_string_or_int(
          input_tensor.dtype,
          prefix='column_name: {} input_tensor'.format(self.key))
  
      key_dtype = self.dtype
      if input_tensor.dtype.is_integer:
        # `index_table_from_file` requires 64-bit integer keys.
        key_dtype = dtypes.int64
        input_tensor = math_ops.cast(input_tensor, dtypes.int64)
  
      name = '{}_lookup'.format(self.key)
      table = lookup_ops.index_table_from_file(
          vocabulary_file=self.vocabulary_file,
          num_oov_buckets=self.num_oov_buckets,
          vocab_size=self.vocabulary_size,
          default_value=self.default_value,
          key_dtype=key_dtype,
          name=name)
      if state_manager is not None:
        state_manager.add_resource(self, name, table)
      return table.lookup(input_tensor)
  
    def transform_feature(self, transformation_cache, state_manager):
      """Creates a lookup table for the vocabulary."""
      input_tensor = _to_sparse_input_and_drop_ignore_values(
          transformation_cache.get(self.key, state_manager))
      return self._transform_input_tensor(input_tensor, state_manager)
  
    @deprecation.deprecated(_FEATURE_COLUMN_DEPRECATION_DATE,
                            _FEATURE_COLUMN_DEPRECATION)
    def _transform_feature(self, inputs):
      input_tensor = _to_sparse_input_and_drop_ignore_values(inputs.get(self.key))
      return self._transform_input_tensor(input_tensor)
  
    @property
    def num_buckets(self):
      """Returns number of buckets in this sparse feature."""
      return self.vocabulary_size + self.num_oov_buckets
  
    @property
    @deprecation.deprecated(_FEATURE_COLUMN_DEPRECATION_DATE,
                            _FEATURE_COLUMN_DEPRECATION)
    def _num_buckets(self):
      return self.num_buckets
  
    def get_sparse_tensors(self, transformation_cache, state_manager):
      """See `CategoricalColumn` base class."""
      return CategoricalColumn.IdWeightPair(
          transformation_cache.get(self, state_manager), None)
  
    @deprecation.deprecated(_FEATURE_COLUMN_DEPRECATION_DATE,
                            _FEATURE_COLUMN_DEPRECATION)
    def _get_sparse_tensors(self, inputs, weight_collections=None,
                            trainable=None):
      del weight_collections
      del trainable
      return CategoricalColumn.IdWeightPair(inputs.get(self), None)
  
    @property
    def parents(self):
      """See 'FeatureColumn` base class."""
      return [self.key]
  
    def _get_config(self):
      """See 'FeatureColumn` base class."""
      config = dict(zip(self._fields, self))
      config['dtype'] = self.dtype.name
      return config
  
    @classmethod
    def _from_config(cls, config, custom_objects=None, columns_by_name=None):
      """See 'FeatureColumn` base class."""
      _check_config_keys(config, cls._fields)
      kwargs = _standardize_and_copy_config(config)
      kwargs['dtype'] = dtypes.as_dtype(config['dtype'])
      return cls(**kwargs)
  
  
  class VocabularyListCategoricalColumn(
      CategoricalColumn,
      fc_old._CategoricalColumn,  # pylint: disable=protected-access
      collections.namedtuple(
          'VocabularyListCategoricalColumn',
          ('key', 'vocabulary_list', 'dtype', 'default_value', 'num_oov_buckets'))
  ):
    """See `categorical_column_with_vocabulary_list`."""
  
    @property
    def _is_v2_column(self):
      return True
  
    @property
    def name(self):
      """See `FeatureColumn` base class."""
      return self.key
  
    @property
    def parse_example_spec(self):
      """See `FeatureColumn` base class."""
      return {self.key: parsing_ops.VarLenFeature(self.dtype)}
  
    @property
    @deprecation.deprecated(_FEATURE_COLUMN_DEPRECATION_DATE,
                            _FEATURE_COLUMN_DEPRECATION)
    def _parse_example_spec(self):
      return self.parse_example_spec
  
    def _transform_input_tensor(self, input_tensor, state_manager=None):
      """Creates a lookup table for the vocabulary list."""
      if self.dtype.is_integer != input_tensor.dtype.is_integer:
        raise ValueError(
            'Column dtype and SparseTensors dtype must be compatible. '
            'key: {}, column dtype: {}, tensor dtype: {}'.format(
                self.key, self.dtype, input_tensor.dtype))
  
      fc_utils.assert_string_or_int(
          input_tensor.dtype,
          prefix='column_name: {} input_tensor'.format(self.key))
  
      key_dtype = self.dtype
      if input_tensor.dtype.is_integer:
        # `index_table_from_tensor` requires 64-bit integer keys.
        key_dtype = dtypes.int64
        input_tensor = math_ops.cast(input_tensor, dtypes.int64)
  
      name = '{}_lookup'.format(self.key)
      table = lookup_ops.index_table_from_tensor(
          vocabulary_list=tuple(self.vocabulary_list),
          default_value=self.default_value,
          num_oov_buckets=self.num_oov_buckets,
          dtype=key_dtype,
          name=name)
      if state_manager is not None:
        state_manager.add_resource(self, name, table)
      return table.lookup(input_tensor)
  
    def transform_feature(self, transformation_cache, state_manager):
      """Creates a lookup table for the vocabulary list."""
      input_tensor = _to_sparse_input_and_drop_ignore_values(
          transformation_cache.get(self.key, state_manager))
      return self._transform_input_tensor(input_tensor, state_manager)
  
    @deprecation.deprecated(_FEATURE_COLUMN_DEPRECATION_DATE,
                            _FEATURE_COLUMN_DEPRECATION)
    def _transform_feature(self, inputs):
      input_tensor = _to_sparse_input_and_drop_ignore_values(inputs.get(self.key))
      return self._transform_input_tensor(input_tensor)
  
    @property
    def num_buckets(self):
      """Returns number of buckets in this sparse feature."""
      return len(self.vocabulary_list) + self.num_oov_buckets
  
    @property
    @deprecation.deprecated(_FEATURE_COLUMN_DEPRECATION_DATE,
                            _FEATURE_COLUMN_DEPRECATION)
    def _num_buckets(self):
      return self.num_buckets
  
    def get_sparse_tensors(self, transformation_cache, state_manager):
      """See `CategoricalColumn` base class."""
      return CategoricalColumn.IdWeightPair(
          transformation_cache.get(self, state_manager), None)
  
    @deprecation.deprecated(_FEATURE_COLUMN_DEPRECATION_DATE,
                            _FEATURE_COLUMN_DEPRECATION)
    def _get_sparse_tensors(self, inputs, weight_collections=None,
                            trainable=None):
      del weight_collections
      del trainable
      return CategoricalColumn.IdWeightPair(inputs.get(self), None)
  
    @property
    def parents(self):
      """See 'FeatureColumn` base class."""
      return [self.key]
  
    def _get_config(self):
      """See 'FeatureColumn` base class."""
      config = dict(zip(self._fields, self))
      config['dtype'] = self.dtype.name
      return config
  
    @classmethod
    def _from_config(cls, config, custom_objects=None, columns_by_name=None):
      """See 'FeatureColumn` base class."""
      _check_config_keys(config, cls._fields)
      kwargs = _standardize_and_copy_config(config)
      kwargs['dtype'] = dtypes.as_dtype(config['dtype'])
      return cls(**kwargs)
  
  
  class IdentityCategoricalColumn(
      CategoricalColumn,
      fc_old._CategoricalColumn,  # pylint: disable=protected-access
      collections.namedtuple('IdentityCategoricalColumn',
                             ('key', 'number_buckets', 'default_value'))):
  
    """See `categorical_column_with_identity`."""
  
    @property
    def _is_v2_column(self):
      return True
  
    @property
    def name(self):
      """See `FeatureColumn` base class."""
      return self.key
  
    @property
    def parse_example_spec(self):
      """See `FeatureColumn` base class."""
      return {self.key: parsing_ops.VarLenFeature(dtypes.int64)}
  
    @property
    @deprecation.deprecated(_FEATURE_COLUMN_DEPRECATION_DATE,
                            _FEATURE_COLUMN_DEPRECATION)
    def _parse_example_spec(self):
      return self.parse_example_spec
  
    def _transform_input_tensor(self, input_tensor):
      """Returns a SparseTensor with identity values."""
      if not input_tensor.dtype.is_integer:
        raise ValueError(
            'Invalid input, not integer. key: {} dtype: {}'.format(
                self.key, input_tensor.dtype))
  
      values = math_ops.cast(input_tensor.values, dtypes.int64, name='values')
      num_buckets = math_ops.cast(
          self.num_buckets, dtypes.int64, name='num_buckets')
      zero = math_ops.cast(0, dtypes.int64, name='zero')
      if self.default_value is None:
        # Fail if values are out-of-range.
        assert_less = check_ops.assert_less(
            values, num_buckets, data=(values, num_buckets),
            name='assert_less_than_num_buckets')
        assert_greater = check_ops.assert_greater_equal(
            values, zero, data=(values,),
            name='assert_greater_or_equal_0')
        with ops.control_dependencies((assert_less, assert_greater)):
          values = array_ops.identity(values)
      else:
        # Assign default for out-of-range values.
        values = array_ops.where_v2(
            math_ops.logical_or(
                values < zero, values >= num_buckets, name='out_of_range'),
            array_ops.fill(
                dims=array_ops.shape(values),
                value=math_ops.cast(self.default_value, dtypes.int64),
                name='default_values'), values)
  
      return sparse_tensor_lib.SparseTensor(
          indices=input_tensor.indices,
          values=values,
          dense_shape=input_tensor.dense_shape)
  
    def transform_feature(self, transformation_cache, state_manager):
      """Returns a SparseTensor with identity values."""
      input_tensor = _to_sparse_input_and_drop_ignore_values(
          transformation_cache.get(self.key, state_manager))
      return self._transform_input_tensor(input_tensor)
  
    @deprecation.deprecated(_FEATURE_COLUMN_DEPRECATION_DATE,
                            _FEATURE_COLUMN_DEPRECATION)
    def _transform_feature(self, inputs):
      input_tensor = _to_sparse_input_and_drop_ignore_values(inputs.get(self.key))
      return self._transform_input_tensor(input_tensor)
  
    @property
    def num_buckets(self):
      """Returns number of buckets in this sparse feature."""
      return self.number_buckets
  
    @property
    @deprecation.deprecated(_FEATURE_COLUMN_DEPRECATION_DATE,
                            _FEATURE_COLUMN_DEPRECATION)
    def _num_buckets(self):
      return self.num_buckets
  
    def get_sparse_tensors(self, transformation_cache, state_manager):
      """See `CategoricalColumn` base class."""
      return CategoricalColumn.IdWeightPair(
          transformation_cache.get(self, state_manager), None)
  
    @deprecation.deprecated(_FEATURE_COLUMN_DEPRECATION_DATE,
                            _FEATURE_COLUMN_DEPRECATION)
    def _get_sparse_tensors(self, inputs, weight_collections=None,
                            trainable=None):
      del weight_collections
      del trainable
      return CategoricalColumn.IdWeightPair(inputs.get(self), None)
  
    @property
    def parents(self):
      """See 'FeatureColumn` base class."""
      return [self.key]
  
    def _get_config(self):
      """See 'FeatureColumn` base class."""
      return dict(zip(self._fields, self))
  
    @classmethod
    def _from_config(cls, config, custom_objects=None, columns_by_name=None):
      """See 'FeatureColumn` base class."""
      _check_config_keys(config, cls._fields)
      kwargs = _standardize_and_copy_config(config)
      return cls(**kwargs)
  
  
  class WeightedCategoricalColumn(
      CategoricalColumn,
      fc_old._CategoricalColumn,  # pylint: disable=protected-access
      collections.namedtuple(
          'WeightedCategoricalColumn',
          ('categorical_column', 'weight_feature_key', 'dtype'))):
    """See `weighted_categorical_column`."""
  
    @property
    def _is_v2_column(self):
      return (isinstance(self.categorical_column, FeatureColumn) and
              self.categorical_column._is_v2_column)  # pylint: disable=protected-access
  
    @property
    def name(self):
      """See `FeatureColumn` base class."""
      return '{}_weighted_by_{}'.format(
          self.categorical_column.name, self.weight_feature_key)
  
    @property
    def parse_example_spec(self):
      """See `FeatureColumn` base class."""
      config = self.categorical_column.parse_example_spec
      if self.weight_feature_key in config:
        raise ValueError('Parse config {} already exists for {}.'.format(
            config[self.weight_feature_key], self.weight_feature_key))
      config[self.weight_feature_key] = parsing_ops.VarLenFeature(self.dtype)
      return config
  
    @property
    @deprecation.deprecated(_FEATURE_COLUMN_DEPRECATION_DATE,
                            _FEATURE_COLUMN_DEPRECATION)
    def _parse_example_spec(self):
      config = self.categorical_column._parse_example_spec  # pylint: disable=protected-access
      if self.weight_feature_key in config:
        raise ValueError('Parse config {} already exists for {}.'.format(
            config[self.weight_feature_key], self.weight_feature_key))
      config[self.weight_feature_key] = parsing_ops.VarLenFeature(self.dtype)
      return config
  
    @property
    def num_buckets(self):
      """See `DenseColumn` base class."""
      return self.categorical_column.num_buckets
  
    @property
    @deprecation.deprecated(_FEATURE_COLUMN_DEPRECATION_DATE,
                            _FEATURE_COLUMN_DEPRECATION)
    def _num_buckets(self):
      return self.categorical_column._num_buckets  # pylint: disable=protected-access
  
    def _transform_weight_tensor(self, weight_tensor):
      if weight_tensor is None:
        raise ValueError('Missing weights {}.'.format(self.weight_feature_key))
      weight_tensor = sparse_tensor_lib.convert_to_tensor_or_sparse_tensor(
          weight_tensor)
      if self.dtype != weight_tensor.dtype.base_dtype:
        raise ValueError('Bad dtype, expected {}, but got {}.'.format(
            self.dtype, weight_tensor.dtype))
      if not isinstance(weight_tensor, sparse_tensor_lib.SparseTensor):
        # The weight tensor can be a regular Tensor. In this case, sparsify it.
        weight_tensor = _to_sparse_input_and_drop_ignore_values(
            weight_tensor, ignore_value=0.0)
      if not weight_tensor.dtype.is_floating:
        weight_tensor = math_ops.cast(weight_tensor, dtypes.float32)
      return weight_tensor
  
    def transform_feature(self, transformation_cache, state_manager):
      """Applies weights to tensor generated from `categorical_column`'."""
      weight_tensor = transformation_cache.get(self.weight_feature_key,
                                               state_manager)
      weight_tensor = self._transform_weight_tensor(weight_tensor)
      return (transformation_cache.get(self.categorical_column, state_manager),
              weight_tensor)
  
    @deprecation.deprecated(_FEATURE_COLUMN_DEPRECATION_DATE,
                            _FEATURE_COLUMN_DEPRECATION)
    def _transform_feature(self, inputs):
      """Applies weights to tensor generated from `categorical_column`'."""
      weight_tensor = inputs.get(self.weight_feature_key)
      weight_tensor = self._transform_weight_tensor(weight_tensor)
      return (inputs.get(self.categorical_column), weight_tensor)
  
    def get_sparse_tensors(self, transformation_cache, state_manager):
      """See `CategoricalColumn` base class."""
      tensors = transformation_cache.get(self, state_manager)
      return CategoricalColumn.IdWeightPair(tensors[0], tensors[1])
  
    @deprecation.deprecated(_FEATURE_COLUMN_DEPRECATION_DATE,
                            _FEATURE_COLUMN_DEPRECATION)
    def _get_sparse_tensors(self, inputs, weight_collections=None,
                            trainable=None):
      del weight_collections
      del trainable
      tensors = inputs.get(self)
      return CategoricalColumn.IdWeightPair(tensors[0], tensors[1])
  
    @property
    def parents(self):
      """See 'FeatureColumn` base class."""
      return [self.categorical_column, self.weight_feature_key]
  
    def _get_config(self):
      """See 'FeatureColumn` base class."""
      from tensorflow.python.feature_column.serialization import serialize_feature_column  # pylint: disable=g-import-not-at-top
      config = dict(zip(self._fields, self))
      config['categorical_column'] = serialize_feature_column(
          self.categorical_column)
      config['dtype'] = self.dtype.name
      return config
  
    @classmethod
    def _from_config(cls, config, custom_objects=None, columns_by_name=None):
      """See 'FeatureColumn` base class."""
      from tensorflow.python.feature_column.serialization import deserialize_feature_column  # pylint: disable=g-import-not-at-top
      _check_config_keys(config, cls._fields)
      kwargs = _standardize_and_copy_config(config)
      kwargs['categorical_column'] = deserialize_feature_column(
          config['categorical_column'], custom_objects, columns_by_name)
      kwargs['dtype'] = dtypes.as_dtype(config['dtype'])
      return cls(**kwargs)
  
  
  class CrossedColumn(
      CategoricalColumn,
      fc_old._CategoricalColumn,  # pylint: disable=protected-access
      collections.namedtuple('CrossedColumn',
                             ('keys', 'hash_bucket_size', 'hash_key'))):
    """See `crossed_column`."""
  
    @property
    def _is_v2_column(self):
      for key in _collect_leaf_level_keys(self):
        if isinstance(key, six.string_types):
          continue
        if not isinstance(key, FeatureColumn):
          return False
        if not key._is_v2_column:  # pylint: disable=protected-access
          return False
      return True
  
    @property
    def name(self):
      """See `FeatureColumn` base class."""
      feature_names = []
      for key in _collect_leaf_level_keys(self):
        if isinstance(key, (FeatureColumn, fc_old._FeatureColumn)):  # pylint: disable=protected-access
          feature_names.append(key.name)
        else:  # key must be a string
          feature_names.append(key)
      return '_X_'.join(sorted(feature_names))
  
    @property
    def parse_example_spec(self):
      """See `FeatureColumn` base class."""
      config = {}
      for key in self.keys:
        if isinstance(key, FeatureColumn):
          config.update(key.parse_example_spec)
        elif isinstance(key, fc_old._FeatureColumn):  # pylint: disable=protected-access
          config.update(key._parse_example_spec)  # pylint: disable=protected-access
        else:  # key must be a string
          config.update({key: parsing_ops.VarLenFeature(dtypes.string)})
      return config
  
    @property
    @deprecation.deprecated(_FEATURE_COLUMN_DEPRECATION_DATE,
                            _FEATURE_COLUMN_DEPRECATION)
    def _parse_example_spec(self):
      return self.parse_example_spec
  
    def transform_feature(self, transformation_cache, state_manager):
      """Generates a hashed sparse cross from the input tensors."""
      feature_tensors = []
      for key in _collect_leaf_level_keys(self):
        if isinstance(key, six.string_types):
          feature_tensors.append(transformation_cache.get(key, state_manager))
        elif isinstance(key, (fc_old._CategoricalColumn, CategoricalColumn)):  # pylint: disable=protected-access
          ids_and_weights = key.get_sparse_tensors(transformation_cache,
                                                   state_manager)
          if ids_and_weights.weight_tensor is not None:
            raise ValueError(
                'crossed_column does not support weight_tensor, but the given '
                'column populates weight_tensor. '
                'Given column: {}'.format(key.name))
          feature_tensors.append(ids_and_weights.id_tensor)
        else:
          raise ValueError('Unsupported column type. Given: {}'.format(key))
      return sparse_ops.sparse_cross_hashed(
          inputs=feature_tensors,
          num_buckets=self.hash_bucket_size,
          hash_key=self.hash_key)
  
    @deprecation.deprecated(_FEATURE_COLUMN_DEPRECATION_DATE,
                            _FEATURE_COLUMN_DEPRECATION)
    def _transform_feature(self, inputs):
      """Generates a hashed sparse cross from the input tensors."""
      feature_tensors = []
      for key in _collect_leaf_level_keys(self):
        if isinstance(key, six.string_types):
          feature_tensors.append(inputs.get(key))
        elif isinstance(key, (CategoricalColumn, fc_old._CategoricalColumn)):  # pylint: disable=protected-access
          ids_and_weights = key._get_sparse_tensors(inputs)  # pylint: disable=protected-access
          if ids_and_weights.weight_tensor is not None:
            raise ValueError(
                'crossed_column does not support weight_tensor, but the given '
                'column populates weight_tensor. '
                'Given column: {}'.format(key.name))
          feature_tensors.append(ids_and_weights.id_tensor)
        else:
          raise ValueError('Unsupported column type. Given: {}'.format(key))
      return sparse_ops.sparse_cross_hashed(
          inputs=feature_tensors,
          num_buckets=self.hash_bucket_size,
          hash_key=self.hash_key)
  
    @property
    def num_buckets(self):
      """Returns number of buckets in this sparse feature."""
      return self.hash_bucket_size
  
    @property
    @deprecation.deprecated(_FEATURE_COLUMN_DEPRECATION_DATE,
                            _FEATURE_COLUMN_DEPRECATION)
    def _num_buckets(self):
      return self.num_buckets
  
    def get_sparse_tensors(self, transformation_cache, state_manager):
      """See `CategoricalColumn` base class."""
      return CategoricalColumn.IdWeightPair(
          transformation_cache.get(self, state_manager), None)
  
    @deprecation.deprecated(_FEATURE_COLUMN_DEPRECATION_DATE,
                            _FEATURE_COLUMN_DEPRECATION)
    def _get_sparse_tensors(self, inputs, weight_collections=None,
                            trainable=None):
      """See `CategoricalColumn` base class."""
      del weight_collections
      del trainable
      return CategoricalColumn.IdWeightPair(inputs.get(self), None)
  
    @property
    def parents(self):
      """See 'FeatureColumn` base class."""
      return list(self.keys)
  
    def _get_config(self):
      """See 'FeatureColumn` base class."""
      from tensorflow.python.feature_column.serialization import serialize_feature_column  # pylint: disable=g-import-not-at-top
      config = dict(zip(self._fields, self))
      config['keys'] = tuple([serialize_feature_column(fc) for fc in self.keys])
      return config
  
    @classmethod
    def _from_config(cls, config, custom_objects=None, columns_by_name=None):
      """See 'FeatureColumn` base class."""
      from tensorflow.python.feature_column.serialization import deserialize_feature_column  # pylint: disable=g-import-not-at-top
      _check_config_keys(config, cls._fields)
      kwargs = _standardize_and_copy_config(config)
      kwargs['keys'] = tuple([
          deserialize_feature_column(c, custom_objects, columns_by_name)
          for c in config['keys']
      ])
      return cls(**kwargs)
  
  
  def _collect_leaf_level_keys(cross):
    """Collects base keys by expanding all nested crosses.
  
    Args:
      cross: A `CrossedColumn`.
  
    Returns:
      A list of strings or `CategoricalColumn` instances.
    """
    leaf_level_keys = []
    for k in cross.keys:
      if isinstance(k, CrossedColumn):
        leaf_level_keys.extend(_collect_leaf_level_keys(k))
      else:
        leaf_level_keys.append(k)
    return leaf_level_keys
  
  
  def _prune_invalid_ids(sparse_ids, sparse_weights):
    """Prune invalid IDs (< 0) from the input ids and weights."""
    is_id_valid = math_ops.greater_equal(sparse_ids.values, 0)
    if sparse_weights is not None:
      is_id_valid = math_ops.logical_and(
          is_id_valid,
          array_ops.ones_like(sparse_weights.values, dtype=dtypes.bool))
    sparse_ids = sparse_ops.sparse_retain(sparse_ids, is_id_valid)
    if sparse_weights is not None:
      sparse_weights = sparse_ops.sparse_retain(sparse_weights, is_id_valid)
    return sparse_ids, sparse_weights
  
  
  def _prune_invalid_weights(sparse_ids, sparse_weights):
    """Prune invalid weights (< 0) from the input ids and weights."""
    if sparse_weights is not None:
      is_weights_valid = math_ops.greater(sparse_weights.values, 0)
      sparse_ids = sparse_ops.sparse_retain(sparse_ids, is_weights_valid)
      sparse_weights = sparse_ops.sparse_retain(sparse_weights, is_weights_valid)
    return sparse_ids, sparse_weights
  
  
  class IndicatorColumn(
      DenseColumn,
      SequenceDenseColumn,
      fc_old._DenseColumn,  # pylint: disable=protected-access
      fc_old._SequenceDenseColumn,  # pylint: disable=protected-access
      collections.namedtuple('IndicatorColumn', ('categorical_column'))):
    """Represents a one-hot column for use in deep networks.
  
    Args:
      categorical_column: A `CategoricalColumn` which is created by
        `categorical_column_with_*` function.
    """
  
    @property
    def _is_v2_column(self):
      return (isinstance(self.categorical_column, FeatureColumn) and
              self.categorical_column._is_v2_column)  # pylint: disable=protected-access
  
    @property
    def name(self):
      """See `FeatureColumn` base class."""
      return '{}_indicator'.format(self.categorical_column.name)
  
    def _transform_id_weight_pair(self, id_weight_pair):
      id_tensor = id_weight_pair.id_tensor
      weight_tensor = id_weight_pair.weight_tensor
  
      # If the underlying column is weighted, return the input as a dense tensor.
      if weight_tensor is not None:
        weighted_column = sparse_ops.sparse_merge(
            sp_ids=id_tensor,
            sp_values=weight_tensor,
            vocab_size=int(self._variable_shape[-1]))
        # Remove (?, -1) index.
        weighted_column = sparse_ops.sparse_slice(weighted_column, [0, 0],
                                                  weighted_column.dense_shape)
        # Use scatter_nd to merge duplicated indices if existed,
        # instead of sparse_tensor_to_dense.
        return array_ops.scatter_nd(weighted_column.indices,
                                    weighted_column.values,
                                    weighted_column.dense_shape)
  
      dense_id_tensor = sparse_ops.sparse_tensor_to_dense(
          id_tensor, default_value=-1)
  
      # One hot must be float for tf.concat reasons since all other inputs to
      # input_layer are float32.
      one_hot_id_tensor = array_ops.one_hot(
          dense_id_tensor,
          depth=self._variable_shape[-1],
          on_value=1.0,
          off_value=0.0)
  
      # Reduce to get a multi-hot per example.
      return math_ops.reduce_sum(one_hot_id_tensor, axis=[-2])
  
    def transform_feature(self, transformation_cache, state_manager):
      """Returns dense `Tensor` representing feature.
  
      Args:
        transformation_cache: A `FeatureTransformationCache` object to access
          features.
        state_manager: A `StateManager` to create / access resources such as
          lookup tables.
  
      Returns:
        Transformed feature `Tensor`.
  
      Raises:
        ValueError: if input rank is not known at graph building time.
      """
      id_weight_pair = self.categorical_column.get_sparse_tensors(
          transformation_cache, state_manager)
      return self._transform_id_weight_pair(id_weight_pair)
  
    @deprecation.deprecated(_FEATURE_COLUMN_DEPRECATION_DATE,
                            _FEATURE_COLUMN_DEPRECATION)
    def _transform_feature(self, inputs):
      id_weight_pair = self.categorical_column._get_sparse_tensors(inputs)  # pylint: disable=protected-access
      return self._transform_id_weight_pair(id_weight_pair)
  
    @property
    def parse_example_spec(self):
      """See `FeatureColumn` base class."""
      return self.categorical_column.parse_example_spec
  
    @property
    @deprecation.deprecated(_FEATURE_COLUMN_DEPRECATION_DATE,
                            _FEATURE_COLUMN_DEPRECATION)
    def _parse_example_spec(self):
      return self.categorical_column._parse_example_spec  # pylint: disable=protected-access
  
    @property
    def variable_shape(self):
      """Returns a `TensorShape` representing the shape of the dense `Tensor`."""
      if isinstance(self.categorical_column, FeatureColumn):
        return tensor_shape.TensorShape([1, self.categorical_column.num_buckets])
      else:
        return tensor_shape.TensorShape([1, self.categorical_column._num_buckets])  # pylint: disable=protected-access
  
    @property
    @deprecation.deprecated(_FEATURE_COLUMN_DEPRECATION_DATE,
                            _FEATURE_COLUMN_DEPRECATION)
    def _variable_shape(self):
      return tensor_shape.TensorShape([1, self.categorical_column._num_buckets])  # pylint: disable=protected-access
  
    def get_dense_tensor(self, transformation_cache, state_manager):
      """Returns dense `Tensor` representing feature.
  
      Args:
        transformation_cache: A `FeatureTransformationCache` object to access
          features.
        state_manager: A `StateManager` to create / access resources such as
          lookup tables.
  
      Returns:
        Dense `Tensor` created within `transform_feature`.
  
      Raises:
        ValueError: If `categorical_column` is a `SequenceCategoricalColumn`.
      """
      if isinstance(self.categorical_column, SequenceCategoricalColumn):
        raise ValueError(
            'In indicator_column: {}. '
            'categorical_column must not be of type SequenceCategoricalColumn. '
            'Suggested fix A: If you wish to use DenseFeatures, use a '
            'non-sequence categorical_column_with_*. '
            'Suggested fix B: If you wish to create sequence input, use '
            'SequenceFeatures instead of DenseFeatures. '
            'Given (type {}): {}'.format(self.name, type(self.categorical_column),
                                         self.categorical_column))
      # Feature has been already transformed. Return the intermediate
      # representation created by transform_feature.
      return transformation_cache.get(self, state_manager)
  
    @deprecation.deprecated(_FEATURE_COLUMN_DEPRECATION_DATE,
                            _FEATURE_COLUMN_DEPRECATION)
    def _get_dense_tensor(self, inputs, weight_collections=None, trainable=None):
      del weight_collections
      del trainable
      if isinstance(
          self.categorical_column,
          (SequenceCategoricalColumn, fc_old._SequenceCategoricalColumn)):  # pylint: disable=protected-access
        raise ValueError(
            'In indicator_column: {}. '
            'categorical_column must not be of type _SequenceCategoricalColumn. '
            'Suggested fix A: If you wish to use DenseFeatures, use a '
            'non-sequence categorical_column_with_*. '
            'Suggested fix B: If you wish to create sequence input, use '
            'SequenceFeatures instead of DenseFeatures. '
            'Given (type {}): {}'.format(self.name, type(self.categorical_column),
                                         self.categorical_column))
      # Feature has been already transformed. Return the intermediate
      # representation created by transform_feature.
      return inputs.get(self)
  
    def get_sequence_dense_tensor(self, transformation_cache, state_manager):
      """See `SequenceDenseColumn` base class."""
      if not isinstance(self.categorical_column, SequenceCategoricalColumn):
        raise ValueError(
            'In indicator_column: {}. '
            'categorical_column must be of type SequenceCategoricalColumn '
            'to use SequenceFeatures. '
            'Suggested fix: Use one of sequence_categorical_column_with_*. '
            'Given (type {}): {}'.format(self.name, type(self.categorical_column),
                                         self.categorical_column))
      # Feature has been already transformed. Return the intermediate
      # representation created by transform_feature.
      dense_tensor = transformation_cache.get(self, state_manager)
      sparse_tensors = self.categorical_column.get_sparse_tensors(
          transformation_cache, state_manager)
      sequence_length = fc_utils.sequence_length_from_sparse_tensor(
          sparse_tensors.id_tensor)
      return SequenceDenseColumn.TensorSequenceLengthPair(
          dense_tensor=dense_tensor, sequence_length=sequence_length)
  
    @deprecation.deprecated(_FEATURE_COLUMN_DEPRECATION_DATE,
                            _FEATURE_COLUMN_DEPRECATION)
    def _get_sequence_dense_tensor(self,
                                   inputs,
                                   weight_collections=None,
                                   trainable=None):
      # Do nothing with weight_collections and trainable since no variables are
      # created in this function.
      del weight_collections
      del trainable
      if not isinstance(
          self.categorical_column,
          (SequenceCategoricalColumn, fc_old._SequenceCategoricalColumn)):  # pylint: disable=protected-access
        raise ValueError(
            'In indicator_column: {}. '
            'categorical_column must be of type _SequenceCategoricalColumn '
            'to use SequenceFeatures. '
            'Suggested fix: Use one of sequence_categorical_column_with_*. '
            'Given (type {}): {}'.format(self.name, type(self.categorical_column),
                                         self.categorical_column))
      # Feature has been already transformed. Return the intermediate
      # representation created by _transform_feature.
      dense_tensor = inputs.get(self)
      sparse_tensors = self.categorical_column._get_sparse_tensors(inputs)  # pylint: disable=protected-access
      sequence_length = fc_utils.sequence_length_from_sparse_tensor(
          sparse_tensors.id_tensor)
      return SequenceDenseColumn.TensorSequenceLengthPair(
          dense_tensor=dense_tensor, sequence_length=sequence_length)
  
    @property
    def parents(self):
      """See 'FeatureColumn` base class."""
      return [self.categorical_column]
  
    def _get_config(self):
      """See 'FeatureColumn` base class."""
      from tensorflow.python.feature_column.serialization import serialize_feature_column  # pylint: disable=g-import-not-at-top
      config = dict(zip(self._fields, self))
      config['categorical_column'] = serialize_feature_column(
          self.categorical_column)
      return config
  
    @classmethod
    def _from_config(cls, config, custom_objects=None, columns_by_name=None):
      """See 'FeatureColumn` base class."""
      from tensorflow.python.feature_column.serialization import deserialize_feature_column  # pylint: disable=g-import-not-at-top
      _check_config_keys(config, cls._fields)
      kwargs = _standardize_and_copy_config(config)
      kwargs['categorical_column'] = deserialize_feature_column(
          config['categorical_column'], custom_objects, columns_by_name)
      return cls(**kwargs)
  
  
  def _verify_static_batch_size_equality(tensors, columns):
    """Verify equality between static batch sizes.
  
    Args:
      tensors: iterable of input tensors.
      columns: Corresponding feature columns.
  
    Raises:
      ValueError: in case of mismatched batch sizes.
    """
    # bath_size is a Dimension object.
    expected_batch_size = None
    for i in range(0, len(tensors)):
      batch_size = tensor_shape.Dimension(tensor_shape.dimension_value(
          tensors[i].shape[0]))
      if batch_size.value is not None:
        if expected_batch_size is None:
          bath_size_column_index = i
          expected_batch_size = batch_size
        elif not expected_batch_size.is_compatible_with(batch_size):
          raise ValueError(
              'Batch size (first dimension) of each feature must be same. '
              'Batch size of columns ({}, {}): ({}, {})'.format(
                  columns[bath_size_column_index].name, columns[i].name,
                  expected_batch_size, batch_size))
  
  
  class SequenceCategoricalColumn(
      CategoricalColumn,
      fc_old._SequenceCategoricalColumn,  # pylint: disable=protected-access
      collections.namedtuple('SequenceCategoricalColumn',
                             ('categorical_column'))):
    """Represents sequences of categorical data."""
  
    @property
    def _is_v2_column(self):
      return (isinstance(self.categorical_column, FeatureColumn) and
              self.categorical_column._is_v2_column)  # pylint: disable=protected-access
  
    @property
    def name(self):
      """See `FeatureColumn` base class."""
      return self.categorical_column.name
  
    @property
    def parse_example_spec(self):
      """See `FeatureColumn` base class."""
      return self.categorical_column.parse_example_spec
  
    @property
    @deprecation.deprecated(_FEATURE_COLUMN_DEPRECATION_DATE,
                            _FEATURE_COLUMN_DEPRECATION)
    def _parse_example_spec(self):
      return self.categorical_column._parse_example_spec  # pylint: disable=protected-access
  
    def transform_feature(self, transformation_cache, state_manager):
      """See `FeatureColumn` base class."""
      return self.categorical_column.transform_feature(transformation_cache,
                                                       state_manager)
  
    @deprecation.deprecated(_FEATURE_COLUMN_DEPRECATION_DATE,
                            _FEATURE_COLUMN_DEPRECATION)
    def _transform_feature(self, inputs):
      return self.categorical_column._transform_feature(inputs)  # pylint: disable=protected-access
  
    @property
    def num_buckets(self):
      """Returns number of buckets in this sparse feature."""
      return self.categorical_column.num_buckets
  
    @property
    @deprecation.deprecated(_FEATURE_COLUMN_DEPRECATION_DATE,
                            _FEATURE_COLUMN_DEPRECATION)
    def _num_buckets(self):
      return self.categorical_column._num_buckets  # pylint: disable=protected-access
  
    def _get_sparse_tensors_helper(self, sparse_tensors):
      id_tensor = sparse_tensors.id_tensor
      weight_tensor = sparse_tensors.weight_tensor
      # Expands third dimension, if necessary so that embeddings are not
      # combined during embedding lookup. If the tensor is already 3D, leave
      # as-is.
      shape = array_ops.shape(id_tensor)
      # Compute the third dimension explicitly instead of setting it to -1, as
      # that doesn't work for dynamically shaped tensors with 0-length at runtime.
      # This happens for empty sequences.
      target_shape = [shape[0], shape[1], math_ops.reduce_prod(shape[2:])]
      id_tensor = sparse_ops.sparse_reshape(id_tensor, target_shape)
      if weight_tensor is not None:
        weight_tensor = sparse_ops.sparse_reshape(weight_tensor, target_shape)
      return CategoricalColumn.IdWeightPair(id_tensor, weight_tensor)
  
    def get_sparse_tensors(self, transformation_cache, state_manager):
      """Returns an IdWeightPair.
  
      `IdWeightPair` is a pair of `SparseTensor`s which represents ids and
      weights.
  
      `IdWeightPair.id_tensor` is typically a `batch_size` x `num_buckets`
      `SparseTensor` of `int64`. `IdWeightPair.weight_tensor` is either a
      `SparseTensor` of `float` or `None` to indicate all weights should be
      taken to be 1. If specified, `weight_tensor` must have exactly the same
      shape and indices as `sp_ids`. Expected `SparseTensor` is same as parsing
      output of a `VarLenFeature` which is a ragged matrix.
  
      Args:
        transformation_cache: A `FeatureTransformationCache` object to access
          features.
        state_manager: A `StateManager` to create / access resources such as
          lookup tables.
      """
      sparse_tensors = self.categorical_column.get_sparse_tensors(
          transformation_cache, state_manager)
      return self._get_sparse_tensors_helper(sparse_tensors)
  
    @deprecation.deprecated(_FEATURE_COLUMN_DEPRECATION_DATE,
                            _FEATURE_COLUMN_DEPRECATION)
    def _get_sparse_tensors(self, inputs, weight_collections=None,
                            trainable=None):
      sparse_tensors = self.categorical_column._get_sparse_tensors(inputs)  # pylint: disable=protected-access
      return self._get_sparse_tensors_helper(sparse_tensors)
  
    @property
    def parents(self):
      """See 'FeatureColumn` base class."""
      return [self.categorical_column]
  
    def _get_config(self):
      """See 'FeatureColumn` base class."""
      from tensorflow.python.feature_column.serialization import serialize_feature_column  # pylint: disable=g-import-not-at-top
      config = dict(zip(self._fields, self))
      config['categorical_column'] = serialize_feature_column(
          self.categorical_column)
      return config
  
    @classmethod
    def _from_config(cls, config, custom_objects=None, columns_by_name=None):
      """See 'FeatureColumn` base class."""
      from tensorflow.python.feature_column.serialization import deserialize_feature_column  # pylint: disable=g-import-not-at-top
      _check_config_keys(config, cls._fields)
      kwargs = _standardize_and_copy_config(config)
      kwargs['categorical_column'] = deserialize_feature_column(
          config['categorical_column'], custom_objects, columns_by_name)
      return cls(**kwargs)
  
  
  def _check_config_keys(config, expected_keys):
    """Checks that a config has all expected_keys."""
    if set(config.keys()) != set(expected_keys):
      raise ValueError('Invalid config: {}, expected keys: {}'.format(
          config, expected_keys))
  
  
  def _standardize_and_copy_config(config):
    """Returns a shallow copy of config with lists turned to tuples.
  
    Keras serialization uses nest to listify everything.
    This causes problems with the NumericColumn shape, which becomes
    unhashable. We could try to solve this on the Keras side, but that
    would require lots of tracking to avoid changing existing behavior.
    Instead, we ensure here that we revive correctly.
  
    Args:
      config: dict that will be used to revive a Feature Column
  
    Returns:
      Shallow copy of config with lists turned to tuples.
    """
    kwargs = config.copy()
    for k, v in kwargs.items():
      if isinstance(v, list):
        kwargs[k] = tuple(v)
  
    return kwargs
  