Field stores its own value, so it can be used directly outside of a model.

value¶

Read or assign the standalone field value. Assignment validates the value and stores transformed values returned by func(...) or model(...).

from dictify import Field

field = Field(required=True).instance(str)

field.value = "hello"
assert field.value == "hello"

Reading value from a required field before assignment raises Field.RequiredError. Failed assignments raise Field.VerifyError and leave the previous value unchanged.

reset()¶

Reset value to the configured default. If there is no default, reset it to UNDEF.

field = Field(default="draft")
field.value = "hello"
field.reset()

assert field.value == "draft"

default¶

Return the materialized default value. If the field was configured with a default factory, the factory is called each time default is read.

from datetime import UTC, datetime

created_at = Field(default=lambda: datetime.now(UTC))
assert isinstance(created_at.default, datetime)

get_default() is kept as a compatibility alias for default.

has_default¶

Return whether the field was configured with a default. None counts as a configured default.

required_name = Field(required=True)
optional_note = Field(default=None)

assert required_name.has_default is False
assert optional_note.has_default is True

validate(value)¶

Validate a value without assigning it to the field. The returned value is the final value after runtime type checks and validator transformations.

field = Field().instance(str).func(str.upper)
assert field.validate("draft") == "DRAFT"

clone()¶

Create a fresh field with the same validation definition and independent standalone state.

email = Field(required=True).instance(str).match(r".+@.+")
other_email = email.clone()

When a Field is declared on a Model class, that class attribute acts as a shared schema definition. Individual model instances keep their runtime values separately.