tf.feature_column.categorical_column_with_vocabulary_file
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A CategoricalColumn
with a vocabulary file.
tf.feature_column.categorical_column_with_vocabulary_file( key, vocabulary_file, vocabulary_size=None, num_oov_buckets=0, default_value=None, dtype=tf.dtypes.string )
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.
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.
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:
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. |
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Licensed under the Creative Commons Attribution License 3.0.
Code samples licensed under the Apache 2.0 License.
https://www.tensorflow.org/versions/r1.15/api_docs/python/tf/feature_column/categorical_column_with_vocabulary_file