Field

relationalai.semantics.frontend.base

Field(
    name: str,
    type_: Concept,
    is_input: bool = False,
    is_list: bool = False,
    source: SourcePos | None = None,
)

Describe one named field in a relationship or property.

A Field pairs a field name with a Concept type and marks whether the field is an input and/or list-valued.

Fields are usually created implicitly by parsing a reading string. You typically construct Field objects only when creating a relationship or property with the explicit fields= keyword argument via Model.Relationship or Model.Property.

Parameters

• name

  (str) - Field name used for indexing and display.

• type_

  (Concept) - Concept type of the field.

• is_input

  (bool, default: False) - Whether this field is an input field. In most relationships/properties, all but the last field are inputs and the final field is the output.

• is_list

  (bool, default: False) - Whether the field represents a list of values.

• source

  (SourcePos | None, default: None) - Optional source position used for error reporting.

Examples

Most fields are created implicitly by parsing a reading string:

>>> from relationalai.semantics import Integer, Model, String
>>> m = Model()
>>> Person = m.Concept("Person", identify_by={"id": Integer})
>>> Person.name = m.Property(f"{Person} has {String:name}")
>>> # The Property constructor parses the reading string and produces an
>>> # input field of type Person and an output field named "name" of type String.

You can also declare fields explicitly via fields=. For example, the following is equivalent to the previous example:

>>> from relationalai.semantics.frontend.base import Field
>>> Person.name = m.Property(
...     fields=[Field("person", Person), Field("name", String)],
...     short_name="name"
... )

Attributes

.name

Field.name: str

Field name.

.type

Field.type: Concept

Field concept type.

.is_input

Field.is_input: bool

True for input fields.

.is_list

Field.is_list: bool

True for list-valued fields.

Used By

 semantics > frontend > base
├──  FieldRef
├──  Model
│   ├──  Property
│   └──  Relationship
├──  Property
├──  Reading
├──  Relationship
└──  Value

Referenced By

RelationalAI Documentation
└──  Build With RelationalAI
    └──  Understand how PyRel works > Build a semantic model
        └──  Declare relationships and properties
            ├──  Declare a property with Model.Property
            └──  Declare a relationship with Model.Relationship