RootModel

RootModel class and type definitions.

RootModel

RootModel(
    root: RootModelRootType = PydanticUndefined, **data
)

Bases: BaseModel, Generic[RootModelRootType]

Usage Documentation

RootModel and Custom Root Types

A Pydantic BaseModel for the root object of the model.

Attributes:

Name	Type	Description
root	RootModelRootType	The root object of the model.
__pydantic_root_model__		Whether the model is a RootModel.
__pydantic_private__		Private fields in the model.
__pydantic_extra__		Extra fields in the model.

Source code in pydantic/root_model.py

def __init__(self, /, root: RootModelRootType = PydanticUndefined, **data) -> None:  # type: ignore
    __tracebackhide__ = True
    if data:
        if root is not PydanticUndefined:
            raise ValueError(
                '"RootModel.__init__" accepts either a single positional argument or arbitrary keyword arguments'
            )
        root = data  # type: ignore
    self.__pydantic_validator__.validate_python(root, self_instance=self)

model_construct classmethod

model_construct(
    root: RootModelRootType,
    _fields_set: set[str] | None = None,
) -> Self

Create a new model using the provided root object and update fields set.

Parameters:

Name	Type	Description	Default
root	RootModelRootType	The root object of the model.	required
_fields_set	set[str] | None	The set of fields to be updated.	None

Returns:

Type	Description
Self	The new model.

Raises:

Type	Description
NotImplemented	If the model is not a subclass of RootModel.

Source code in pydantic/root_model.py

@classmethod
def model_construct(cls, root: RootModelRootType, _fields_set: set[str] | None = None) -> Self:  # type: ignore
    """Create a new model using the provided root object and update fields set.

    Args:
        root: The root object of the model.
        _fields_set: The set of fields to be updated.

    Returns:
        The new model.

    Raises:
        NotImplemented: If the model is not a subclass of `RootModel`.
    """
    return super().model_construct(root=root, _fields_set=_fields_set)

model_dump

model_dump(
    *,
    mode: Literal["json", "python"] | str = "python",
    include: IncEx | None = None,
    exclude: IncEx | None = None,
    context: Any | None = None,
    by_alias: bool | None = None,
    exclude_unset: bool = False,
    exclude_defaults: bool = False,
    exclude_none: bool = False,
    exclude_computed_fields: bool = False,
    round_trip: bool = False,
    warnings: (
        bool | Literal["none", "warn", "error"]
    ) = True,
    fallback: Callable[[Any], Any] | None = None,
    serialize_as_any: bool = False,
    polymorphic_serialization: bool | None = None
) -> Any

Usage Documentation

model_dump

Generate a dictionary representation of the model, optionally specifying which fields to include or exclude.

Parameters:

Name	Type	Description	Default
mode	Literal['json', 'python'] | str	The mode in which to_python should run. If mode is 'json', the output will only contain JSON serializable types. If mode is 'python', the output may contain non-JSON-serializable Python objects.	'python'
include	IncEx | None	A set of fields to include in the output.	None
exclude	IncEx | None	A set of fields to exclude from the output.	None
context	Any | None	Additional context to pass to the serializer.	None
by_alias	bool | None	Whether to use the field's alias in the dictionary key if defined.	None
exclude_unset	bool	Whether to exclude fields that have not been explicitly set.	False
exclude_defaults	bool	Whether to exclude fields that are set to their default value.	False
exclude_none	bool	Whether to exclude fields that have a value of None.	False
exclude_computed_fields	bool	Whether to exclude computed fields. While this can be useful for round-tripping, it is usually recommended to use the dedicated round_trip parameter instead.	False
round_trip	bool	If True, dumped values should be valid as input for non-idempotent types such as Json[T].	False
warnings	bool | Literal['none', 'warn', 'error']	How to handle serialization errors. False/"none" ignores them, True/"warn" logs errors, "error" raises a PydanticSerializationError.	True
fallback	Callable[[Any], Any] | None	A function to call when an unknown value is encountered. If not provided, a PydanticSerializationError error is raised.	None
serialize_as_any	bool	Whether to serialize fields with duck-typing serialization behavior.	False
polymorphic_serialization	bool | None	Whether to use model and dataclass polymorphic serialization for this call.	None

Returns:

Type	Description
Any	A dictionary representation of the model.

Source code in pydantic/root_model.py

def model_dump(  # type: ignore
    self,
    *,
    mode: Literal['json', 'python'] | str = 'python',
    include: IncEx | None = None,
    exclude: IncEx | None = None,
    context: Any | None = None,
    by_alias: bool | None = None,
    exclude_unset: bool = False,
    exclude_defaults: bool = False,
    exclude_none: bool = False,
    exclude_computed_fields: bool = False,
    round_trip: bool = False,
    warnings: bool | Literal['none', 'warn', 'error'] = True,
    fallback: Callable[[Any], Any] | None = None,
    serialize_as_any: bool = False,
    polymorphic_serialization: bool | None = None,
) -> Any:
    """!!! abstract "Usage Documentation"
        [`model_dump`](../concepts/serialization.md#python-mode)

    Generate a dictionary representation of the model, optionally specifying which fields to include or exclude.

    Args:
        mode: The mode in which `to_python` should run.
            If mode is 'json', the output will only contain JSON serializable types.
            If mode is 'python', the output may contain non-JSON-serializable Python objects.
        include: A set of fields to include in the output.
        exclude: A set of fields to exclude from the output.
        context: Additional context to pass to the serializer.
        by_alias: Whether to use the field's alias in the dictionary key if defined.
        exclude_unset: Whether to exclude fields that have not been explicitly set.
        exclude_defaults: Whether to exclude fields that are set to their default value.
        exclude_none: Whether to exclude fields that have a value of `None`.
        exclude_computed_fields: Whether to exclude computed fields.
            While this can be useful for round-tripping, it is usually recommended to use the dedicated
            `round_trip` parameter instead.
        round_trip: If True, dumped values should be valid as input for non-idempotent types such as Json[T].
        warnings: How to handle serialization errors. False/"none" ignores them, True/"warn" logs errors,
            "error" raises a [`PydanticSerializationError`][pydantic_core.PydanticSerializationError].
        fallback: A function to call when an unknown value is encountered. If not provided,
            a [`PydanticSerializationError`][pydantic_core.PydanticSerializationError] error is raised.
        serialize_as_any: Whether to serialize fields with duck-typing serialization behavior.
        polymorphic_serialization: Whether to use model and dataclass polymorphic serialization for this call.

    Returns:
        A dictionary representation of the model.
    """
    ...