Property

relationalai.semantics.frontend.base

Represents a single-valued attribute on entities.

A Property is a specialized Relationship that is intended to behave like an attribute (for example, a person’s age or a pet’s name). Unlike a general relationship, a property is treated as single-valued: the non-output fields (all fields except the last) uniquely determine the output field (the last field). For a typical binary property like age(person, value), this means a given person can have at most one age value.

Properties are usually created via Model.Property and assigned as attributes on a Concept. Calling a property produces an Expression that you can use in Model.define, Model.where, and Model.require.

Examples

Declare a property, define a couple of facts, and query:

>>> from relationalai.semantics import Model, Integer, String
>>> m = Model()
>>> Person = m.Concept("Person")
>>> Person.name = m.Property(f"{Person} is named {String:name}")
>>> Person.age = m.Property(f"{Person} is {Integer:age} years old
>>> m.define(Person.new(name="Alice", age=30), Person.new(name="Bob", age=17))
>>> m.where(Person.age >= 18).select(Person.name).to_df()

Notes

Most users should not instantiate this class directly. Prefer Model.Property.

The single-valued behavior is enforced by a uniqueness constraint that is added when the model is compiled. “Single-valued” means at most one output value for a given input; a property can still be missing for some entities.

Inheritance Hierarchy

Used By

 semantics > frontend > base
└──  Concept
    └──  identify_by

Returned By

 semantics > frontend > base
└──  Model
    └──  Property

Referenced By

RelationalAI Documentation
└──  Release Notes
    └──  Python API Release Notes
        └──  What’s New in Version 1.0.0
            └──  Breaking Changes