tf.feature_column.categorical_column_with_vocabulary_list
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A CategoricalColumn
with in-memory vocabulary.
tf.feature_column.categorical_column_with_vocabulary_list( key, vocabulary_list, dtype=None, default_value=-1, num_oov_buckets=0 )
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.
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.
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:
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. |
© 2020 The TensorFlow Authors. All rights reserved.
Licensed under the Creative Commons Attribution License 3.0.
Code samples licensed under the Apache 2.0 License.
https://www.tensorflow.org/versions/r2.4/api_docs/python/tf/feature_column/categorical_column_with_vocabulary_list