Producer.__getattribute__()#

#Producer.__getattribute__(name: str) -> InstanceProperty | None

Restricts the values produced to those for which a property named name is set and returns an InstanceProperty object. .__getattribute__() is called whenever you access a property using dot notation, such as book.title, or person.age.

Parameters#

Returns#

An InstanceProperty object, except for Expression objects, in which case .__getattribute__() returns None.

Example#

It is essential to keep in mind that property access adds a constraint to your context. For example, the following query only returns objects in Person that have a name and age property:

## Add a person with an age property.
with model.rule():
    Person.add(name="Wilma", age=36)

with model.query() as select:
    person = Person()
    # Restrict `person` to objects with an `age` property.
    person.age
    response = select(person.name)

# Fred is not included in the results because he has no `age` property.
print(response.results)
# Output:
#     name
# 0  Wilma

See Also#

• InstanceProperty