The object form of a filter transform predicate.
filter
Vega-Lite accepts either a predicate object ({field, equal}) or a raw expression string; Altair emits the former for alt.FieldEqualPredicate(...) and the latter for alt.datum.f == v.
{field, equal}
alt.FieldEqualPredicate(...)
alt.datum.f == v
Optional
The object form of a
filtertransform predicate.Vega-Lite accepts either a predicate object (
{field, equal}) or a raw expression string; Altair emits the former foralt.FieldEqualPredicate(...)and the latter foralt.datum.f == v.