A feature is an individual measurable property or characteristic of a phenomenon being observed. Features are the most important concepts within a feature store. Feature data is used both as input to models during training and when models are served in production.
In the context of Feast, features are values that are associated with either one or more entities over time. In Feast, these values are either primitives or lists of primitives. Each feature can also have additional information attached to it.
The following is a YAML representation of a feature specification. This specification would form part of a larger specification within a feature set.
total_trips_feature.yaml# Feature namename: total_trips_24h# Feature value typevalue_type: INT64
Features can be created through the Feast SDK as follows
from feast import Entity, Feature, ValueType, FeatureSet# Create a driver entitydriver = Entity("driver_id", ValueType.INT64)# Create a total trips 24h featuretotal_trips_24h = Feature("total_trips_24h", ValueType.INT64)# Create a feature set with a single entity and a single featuredriver_fs = FeatureSet("driver_fs", entities=[driver], features=[total_trips_24h])# Register the feature set with Feastclient.apply(driver_fs)
Please see the FeatureSpec for the complete feature specification API.