tf.contrib.lookup.HashTable

class tf.contrib.lookup.HashTable

A generic hash table implementation.

Example usage:

table = tf.contrib.lookup.HashTable(
    tf.contrib.lookup.KeyValueTensorInitializer(keys, values), -1)
out = table.lookup(input_tensor).
table.init.run()
print out.eval()

Properties

default_value

The default value of the table.

init

The table initialization op.

key_dtype

The table key dtype.

name

The name of the table.

table_ref

Get the underlying table reference.

value_dtype

The table value dtype.

Methods

__init__(initializer, default_value, shared_name=None, name=None)

Creates a non-initialized HashTable object.

Creates a table, the type of its keys and values are specified by the initializer. Before using the table you will have to initialize it. After initialization the table will be immutable.

Args:

  • initializer: The table initializer to use.
  • default_value: The value to use if a key is missing in the table.
  • shared_name: If non-empty, this table will be shared under the given name across multiple sessions.
  • name: A name for the operation (optional).

Returns:

A HashTable object.

check_table_dtypes(key_dtype, value_dtype)

Check that the given key_dtype and value_dtype matches the table dtypes.

Args:

  • key_dtype: The key data type to check.
  • value_dtype: The value data type to check.

Raises:

  • TypeError: when 'key_dtype' or 'value_dtype' doesn't match the table data types.

lookup(keys, name=None)

Looks up keys in a table, outputs the corresponding values.

The default_value is used for keys not present in the table.

Args:

  • keys: Keys to look up. May be either a SparseTensor or dense Tensor.
  • name: A name for the operation (optional).

Returns:

A SparseTensor if keys are sparse, otherwise a dense Tensor.

Raises:

  • TypeError: when keys or default_value doesn't match the table data types.

size(name=None)

Compute the number of elements in this table.

Args:

  • name: A name for the operation (optional).

Returns:

A scalar tensor containing the number of elements in this table.

Defined in tensorflow/contrib/lookup/lookup_ops.py.