A feature spec is a schema-like description of how to extract feature data from a structured input record. It typically specifies the feature keys, data types, and whether each value has fixed or variable length.
Describes the information required to extract features data from the tf.Example protocol buffer. Because the tf.Example protocol buffer is just a container for data, you must specify the following: - The data to extract (that is, the keys for the features) - The data type (for example, float or int) - The length (fixed or variable)