Annotated Style¶

Annotated[...] metadata can declare a model field without assigning a class value.

from typing import Annotated

from dictify import Field, Model


class User(Model):
    email: Annotated[str, Field(required=True).match(r".+@.+")]

dictify uses str as the runtime field type and uses Field(...) as the field definition. This style is friendly to static type checkers because the model attribute is annotated as str without assigning a Field object to it.

Additional Annotated[...] metadata is allowed and ignored for runtime typing.

class User(Model):
    email: Annotated[str, "primary email", Field(required=True)]

Direct Assignment Style¶

dictify also supports assigning Field(...) directly to the class attribute:

class User(Model):
    email: str = Field(required=True).match(r".+@.+")

This style is fully supported at runtime and can be concise for scripts or existing code. For strict static type checking, prefer Annotated[str, Field(...)].

Invalid Mixed Style¶

Do not declare a second Field(...) inside Annotated[...] when the class attribute is already assigned to Field(...).

# Invalid: ambiguous double-field declaration.
email: Annotated[str, Field(required=True)] = Field()