tf.compat.v2.lookup.StaticVocabularyTable

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Class `StaticVocabularyTable`

String to Id table wrapper that assigns out-of-vocabulary keys to buckets.

Inherits From: LookupInterface

For example, if an instance of StaticVocabularyTable is initialized with a string-to-id initializer that maps:

emerson -> 0
lake -> 1
palmer -> 2

The Vocabulary object will performs the following mapping:

emerson -> 0
lake -> 1
palmer -> 2
<other term> -> bucket_id, where bucket_id will be between 3 and 3 + num_oov_buckets - 1, calculated by: hash(<term>) % num_oov_buckets + vocab_size

If input_tensor is ["emerson", "lake", "palmer", "king", "crimson"], the lookup result is [0, 1, 2, 4, 7].

If initializer is None, only out-of-vocabulary buckets are used.

Example usage:

num_oov_buckets = 3
input_tensor = tf.constant(["emerson", "lake", "palmer", "king", "crimnson"])
table = tf.lookup.StaticVocabularyTable(
    tf.TextFileIdTableInitializer(filename), num_oov_buckets)
out = table.lookup(input_tensor).
table.init.run()
print(out.eval())

The hash function used for generating out-of-vocabulary buckets ID is Fingerprint64.

`init`

View source

__init__(
    initializer,
    num_oov_buckets,
    lookup_key_dtype=None,
    name=None
)

Construct a StaticVocabularyTable object.

Args:

initializer: A TableInitializerBase object that contains the data used to initialize the table. If None, then we only use out-of-vocab buckets.
num_oov_buckets: Number of buckets to use for out-of-vocabulary keys. Must be greater than zero.
lookup_key_dtype: Data type of keys passed to lookup. Defaults to initializer.key_dtype if initializer is specified, otherwise tf.string. Must be string or integer, and must be castable to initializer.key_dtype.
name: A name for the operation (optional).

Raises:

ValueError: when num_oov_buckets is not positive.
TypeError: when lookup_key_dtype or initializer.key_dtype are not integer or string. Also when initializer.value_dtype != int64.

Properties

`key_dtype`

The table key dtype.

`name`

The name of the table.

`resource_handle`

Returns the resource handle associated with this Resource.

`value_dtype`

The table value dtype.

Methods