|
- """Defining fields on models."""
-
- from __future__ import annotations as _annotations
-
- import dataclasses
- import inspect
- import sys
- import typing
- from collections.abc import Mapping
- from copy import copy
- from dataclasses import Field as DataclassField
- from functools import cached_property
- from typing import Annotated, Any, Callable, ClassVar, Literal, TypeVar, cast, overload
- from warnings import warn
-
- import annotated_types
- import typing_extensions
- from pydantic_core import PydanticUndefined
- from typing_extensions import Self, TypeAlias, Unpack, deprecated
- from typing_inspection import typing_objects
- from typing_inspection.introspection import UNKNOWN, AnnotationSource, ForbiddenQualifier, Qualifier, inspect_annotation
-
- from . import types
- from ._internal import _decorators, _fields, _generics, _internal_dataclass, _repr, _typing_extra, _utils
- from ._internal._namespace_utils import GlobalsNamespace, MappingNamespace
- from .aliases import AliasChoices, AliasPath
- from .config import JsonDict
- from .errors import PydanticForbiddenQualifier, PydanticUserError
- from .json_schema import PydanticJsonSchemaWarning
- from .warnings import PydanticDeprecatedSince20
-
- if typing.TYPE_CHECKING:
- from ._internal._repr import ReprArgs
- else:
- # See PyCharm issues https://youtrack.jetbrains.com/issue/PY-21915
- # and https://youtrack.jetbrains.com/issue/PY-51428
- DeprecationWarning = PydanticDeprecatedSince20
-
- __all__ = 'Field', 'PrivateAttr', 'computed_field'
-
-
- _Unset: Any = PydanticUndefined
-
- if sys.version_info >= (3, 13):
- import warnings
-
- Deprecated: TypeAlias = warnings.deprecated | deprecated
- else:
- Deprecated: TypeAlias = deprecated
-
-
- class _FromFieldInfoInputs(typing_extensions.TypedDict, total=False):
- """This class exists solely to add type checking for the `**kwargs` in `FieldInfo.from_field`."""
-
- # TODO PEP 747: use TypeForm:
- annotation: type[Any] | None
- default_factory: Callable[[], Any] | Callable[[dict[str, Any]], Any] | None
- alias: str | None
- alias_priority: int | None
- validation_alias: str | AliasPath | AliasChoices | None
- serialization_alias: str | None
- title: str | None
- field_title_generator: Callable[[str, FieldInfo], str] | None
- description: str | None
- examples: list[Any] | None
- exclude: bool | None
- gt: annotated_types.SupportsGt | None
- ge: annotated_types.SupportsGe | None
- lt: annotated_types.SupportsLt | None
- le: annotated_types.SupportsLe | None
- multiple_of: float | None
- strict: bool | None
- min_length: int | None
- max_length: int | None
- pattern: str | typing.Pattern[str] | None
- allow_inf_nan: bool | None
- max_digits: int | None
- decimal_places: int | None
- union_mode: Literal['smart', 'left_to_right'] | None
- discriminator: str | types.Discriminator | None
- deprecated: Deprecated | str | bool | None
- json_schema_extra: JsonDict | Callable[[JsonDict], None] | None
- frozen: bool | None
- validate_default: bool | None
- repr: bool
- init: bool | None
- init_var: bool | None
- kw_only: bool | None
- coerce_numbers_to_str: bool | None
- fail_fast: bool | None
-
-
- class _FieldInfoInputs(_FromFieldInfoInputs, total=False):
- """This class exists solely to add type checking for the `**kwargs` in `FieldInfo.__init__`."""
-
- default: Any
-
-
- class FieldInfo(_repr.Representation):
- """This class holds information about a field.
-
- `FieldInfo` is used for any field definition regardless of whether the [`Field()`][pydantic.fields.Field]
- function is explicitly used.
-
- !!! warning
- You generally shouldn't be creating `FieldInfo` directly, you'll only need to use it when accessing
- [`BaseModel`][pydantic.main.BaseModel] `.model_fields` internals.
-
- Attributes:
- annotation: The type annotation of the field.
- default: The default value of the field.
- default_factory: A callable to generate the default value. The callable can either take 0 arguments
- (in which case it is called as is) or a single argument containing the already validated data.
- alias: The alias name of the field.
- alias_priority: The priority of the field's alias.
- validation_alias: The validation alias of the field.
- serialization_alias: The serialization alias of the field.
- title: The title of the field.
- field_title_generator: A callable that takes a field name and returns title for it.
- description: The description of the field.
- examples: List of examples of the field.
- exclude: Whether to exclude the field from the model serialization.
- discriminator: Field name or Discriminator for discriminating the type in a tagged union.
- deprecated: A deprecation message, an instance of `warnings.deprecated` or the `typing_extensions.deprecated` backport,
- or a boolean. If `True`, a default deprecation message will be emitted when accessing the field.
- json_schema_extra: A dict or callable to provide extra JSON schema properties.
- frozen: Whether the field is frozen.
- validate_default: Whether to validate the default value of the field.
- repr: Whether to include the field in representation of the model.
- init: Whether the field should be included in the constructor of the dataclass.
- init_var: Whether the field should _only_ be included in the constructor of the dataclass, and not stored.
- kw_only: Whether the field should be a keyword-only argument in the constructor of the dataclass.
- metadata: List of metadata constraints.
- """
-
- annotation: type[Any] | None
- default: Any
- default_factory: Callable[[], Any] | Callable[[dict[str, Any]], Any] | None
- alias: str | None
- alias_priority: int | None
- validation_alias: str | AliasPath | AliasChoices | None
- serialization_alias: str | None
- title: str | None
- field_title_generator: Callable[[str, FieldInfo], str] | None
- description: str | None
- examples: list[Any] | None
- exclude: bool | None
- discriminator: str | types.Discriminator | None
- deprecated: Deprecated | str | bool | None
- json_schema_extra: JsonDict | Callable[[JsonDict], None] | None
- frozen: bool | None
- validate_default: bool | None
- repr: bool
- init: bool | None
- init_var: bool | None
- kw_only: bool | None
- metadata: list[Any]
-
- __slots__ = (
- 'annotation',
- 'default',
- 'default_factory',
- 'alias',
- 'alias_priority',
- 'validation_alias',
- 'serialization_alias',
- 'title',
- 'field_title_generator',
- 'description',
- 'examples',
- 'exclude',
- 'discriminator',
- 'deprecated',
- 'json_schema_extra',
- 'frozen',
- 'validate_default',
- 'repr',
- 'init',
- 'init_var',
- 'kw_only',
- 'metadata',
- '_attributes_set',
- '_qualifiers',
- '_complete',
- '_original_assignment',
- '_original_annotation',
- )
-
- # used to convert kwargs to metadata/constraints,
- # None has a special meaning - these items are collected into a `PydanticGeneralMetadata`
- metadata_lookup: ClassVar[dict[str, typing.Callable[[Any], Any] | None]] = {
- 'strict': types.Strict,
- 'gt': annotated_types.Gt,
- 'ge': annotated_types.Ge,
- 'lt': annotated_types.Lt,
- 'le': annotated_types.Le,
- 'multiple_of': annotated_types.MultipleOf,
- 'min_length': annotated_types.MinLen,
- 'max_length': annotated_types.MaxLen,
- 'pattern': None,
- 'allow_inf_nan': None,
- 'max_digits': None,
- 'decimal_places': None,
- 'union_mode': None,
- 'coerce_numbers_to_str': None,
- 'fail_fast': types.FailFast,
- }
-
- def __init__(self, **kwargs: Unpack[_FieldInfoInputs]) -> None:
- """This class should generally not be initialized directly; instead, use the `pydantic.fields.Field` function
- or one of the constructor classmethods.
-
- See the signature of `pydantic.fields.Field` for more details about the expected arguments.
- """
- self._attributes_set = {k: v for k, v in kwargs.items() if v is not _Unset}
- kwargs = {k: _DefaultValues.get(k) if v is _Unset else v for k, v in kwargs.items()} # type: ignore
- self.annotation = kwargs.get('annotation')
-
- default = kwargs.pop('default', PydanticUndefined)
- if default is Ellipsis:
- self.default = PydanticUndefined
- self._attributes_set.pop('default', None)
- else:
- self.default = default
-
- self.default_factory = kwargs.pop('default_factory', None)
-
- if self.default is not PydanticUndefined and self.default_factory is not None:
- raise TypeError('cannot specify both default and default_factory')
-
- self.alias = kwargs.pop('alias', None)
- self.validation_alias = kwargs.pop('validation_alias', None)
- self.serialization_alias = kwargs.pop('serialization_alias', None)
- alias_is_set = any(alias is not None for alias in (self.alias, self.validation_alias, self.serialization_alias))
- self.alias_priority = kwargs.pop('alias_priority', None) or 2 if alias_is_set else None
- self.title = kwargs.pop('title', None)
- self.field_title_generator = kwargs.pop('field_title_generator', None)
- self.description = kwargs.pop('description', None)
- self.examples = kwargs.pop('examples', None)
- self.exclude = kwargs.pop('exclude', None)
- self.discriminator = kwargs.pop('discriminator', None)
- # For compatibility with FastAPI<=0.110.0, we preserve the existing value if it is not overridden
- self.deprecated = kwargs.pop('deprecated', getattr(self, 'deprecated', None))
- self.repr = kwargs.pop('repr', True)
- self.json_schema_extra = kwargs.pop('json_schema_extra', None)
- self.validate_default = kwargs.pop('validate_default', None)
- self.frozen = kwargs.pop('frozen', None)
- # currently only used on dataclasses
- self.init = kwargs.pop('init', None)
- self.init_var = kwargs.pop('init_var', None)
- self.kw_only = kwargs.pop('kw_only', None)
-
- self.metadata = self._collect_metadata(kwargs) # type: ignore
-
- # Private attributes:
- self._qualifiers: set[Qualifier] = set()
- # Used to rebuild FieldInfo instances:
- self._complete = True
- self._original_annotation: Any = PydanticUndefined
- self._original_assignment: Any = PydanticUndefined
-
- @staticmethod
- def from_field(default: Any = PydanticUndefined, **kwargs: Unpack[_FromFieldInfoInputs]) -> FieldInfo:
- """Create a new `FieldInfo` object with the `Field` function.
-
- Args:
- default: The default value for the field. Defaults to Undefined.
- **kwargs: Additional arguments dictionary.
-
- Raises:
- TypeError: If 'annotation' is passed as a keyword argument.
-
- Returns:
- A new FieldInfo object with the given parameters.
-
- Example:
- This is how you can create a field with default value like this:
-
- ```python
- import pydantic
-
- class MyModel(pydantic.BaseModel):
- foo: int = pydantic.Field(4)
- ```
- """
- if 'annotation' in kwargs:
- raise TypeError('"annotation" is not permitted as a Field keyword argument')
- return FieldInfo(default=default, **kwargs)
-
- @staticmethod
- def from_annotation(annotation: type[Any], *, _source: AnnotationSource = AnnotationSource.ANY) -> FieldInfo:
- """Creates a `FieldInfo` instance from a bare annotation.
-
- This function is used internally to create a `FieldInfo` from a bare annotation like this:
-
- ```python
- import pydantic
-
- class MyModel(pydantic.BaseModel):
- foo: int # <-- like this
- ```
-
- We also account for the case where the annotation can be an instance of `Annotated` and where
- one of the (not first) arguments in `Annotated` is an instance of `FieldInfo`, e.g.:
-
- ```python
- from typing import Annotated
-
- import annotated_types
-
- import pydantic
-
- class MyModel(pydantic.BaseModel):
- foo: Annotated[int, annotated_types.Gt(42)]
- bar: Annotated[int, pydantic.Field(gt=42)]
- ```
-
- Args:
- annotation: An annotation object.
-
- Returns:
- An instance of the field metadata.
- """
- try:
- inspected_ann = inspect_annotation(
- annotation,
- annotation_source=_source,
- unpack_type_aliases='skip',
- )
- except ForbiddenQualifier as e:
- raise PydanticForbiddenQualifier(e.qualifier, annotation)
-
- # TODO check for classvar and error?
-
- # No assigned value, this happens when using a bare `Final` qualifier (also for other
- # qualifiers, but they shouldn't appear here). In this case we infer the type as `Any`
- # because we don't have any assigned value.
- type_expr: Any = Any if inspected_ann.type is UNKNOWN else inspected_ann.type
- final = 'final' in inspected_ann.qualifiers
- metadata = inspected_ann.metadata
-
- if not metadata:
- # No metadata, e.g. `field: int`, or `field: Final[str]`:
- field_info = FieldInfo(annotation=type_expr, frozen=final or None)
- field_info._qualifiers = inspected_ann.qualifiers
- return field_info
-
- # With metadata, e.g. `field: Annotated[int, Field(...), Gt(1)]`:
- field_info_annotations = [a for a in metadata if isinstance(a, FieldInfo)]
- field_info = FieldInfo.merge_field_infos(*field_info_annotations, annotation=type_expr)
-
- new_field_info = field_info._copy()
- new_field_info.annotation = type_expr
- new_field_info.frozen = final or field_info.frozen
- field_metadata: list[Any] = []
- for a in metadata:
- if typing_objects.is_deprecated(a):
- new_field_info.deprecated = a.message
- elif not isinstance(a, FieldInfo):
- field_metadata.append(a)
- else:
- field_metadata.extend(a.metadata)
- new_field_info.metadata = field_metadata
- new_field_info._qualifiers = inspected_ann.qualifiers
- return new_field_info
-
- @staticmethod
- def from_annotated_attribute(
- annotation: type[Any], default: Any, *, _source: AnnotationSource = AnnotationSource.ANY
- ) -> FieldInfo:
- """Create `FieldInfo` from an annotation with a default value.
-
- This is used in cases like the following:
-
- ```python
- from typing import Annotated
-
- import annotated_types
-
- import pydantic
-
- class MyModel(pydantic.BaseModel):
- foo: int = 4 # <-- like this
- bar: Annotated[int, annotated_types.Gt(4)] = 4 # <-- or this
- spam: Annotated[int, pydantic.Field(gt=4)] = 4 # <-- or this
- ```
-
- Args:
- annotation: The type annotation of the field.
- default: The default value of the field.
-
- Returns:
- A field object with the passed values.
- """
- if annotation is default:
- raise PydanticUserError(
- 'Error when building FieldInfo from annotated attribute. '
- "Make sure you don't have any field name clashing with a type annotation.",
- code='unevaluable-type-annotation',
- )
-
- try:
- inspected_ann = inspect_annotation(
- annotation,
- annotation_source=_source,
- unpack_type_aliases='skip',
- )
- except ForbiddenQualifier as e:
- raise PydanticForbiddenQualifier(e.qualifier, annotation)
-
- # TODO check for classvar and error?
-
- # TODO infer from the default, this can be done in v3 once we treat final fields with
- # a default as proper fields and not class variables:
- type_expr: Any = Any if inspected_ann.type is UNKNOWN else inspected_ann.type
- final = 'final' in inspected_ann.qualifiers
- metadata = inspected_ann.metadata
-
- if isinstance(default, FieldInfo):
- # e.g. `field: int = Field(...)`
- default_metadata = default.metadata.copy()
- default = copy(default)
- default.metadata = default_metadata
-
- default.annotation = type_expr
- default.metadata += metadata
- merged_default = FieldInfo.merge_field_infos(
- *[x for x in metadata if isinstance(x, FieldInfo)],
- default,
- annotation=default.annotation,
- )
- merged_default.frozen = final or merged_default.frozen
- merged_default._qualifiers = inspected_ann.qualifiers
- return merged_default
-
- if isinstance(default, dataclasses.Field):
- # `collect_dataclass_fields()` passes the dataclass Field as a default.
- pydantic_field = FieldInfo._from_dataclass_field(default)
- pydantic_field.annotation = type_expr
- pydantic_field.metadata += metadata
- pydantic_field = FieldInfo.merge_field_infos(
- *[x for x in metadata if isinstance(x, FieldInfo)],
- pydantic_field,
- annotation=pydantic_field.annotation,
- )
- pydantic_field.frozen = final or pydantic_field.frozen
- pydantic_field.init_var = 'init_var' in inspected_ann.qualifiers
- pydantic_field.init = getattr(default, 'init', None)
- pydantic_field.kw_only = getattr(default, 'kw_only', None)
- pydantic_field._qualifiers = inspected_ann.qualifiers
- return pydantic_field
-
- if not metadata:
- # No metadata, e.g. `field: int = ...`, or `field: Final[str] = ...`:
- field_info = FieldInfo(annotation=type_expr, default=default, frozen=final or None)
- field_info._qualifiers = inspected_ann.qualifiers
- return field_info
-
- # With metadata, e.g. `field: Annotated[int, Field(...), Gt(1)] = ...`:
- field_infos = [a for a in metadata if isinstance(a, FieldInfo)]
- field_info = FieldInfo.merge_field_infos(*field_infos, annotation=type_expr, default=default)
- field_metadata: list[Any] = []
- for a in metadata:
- if typing_objects.is_deprecated(a):
- field_info.deprecated = a.message
- elif not isinstance(a, FieldInfo):
- field_metadata.append(a)
- else:
- field_metadata.extend(a.metadata)
- field_info.metadata = field_metadata
- field_info._qualifiers = inspected_ann.qualifiers
- return field_info
-
- @staticmethod
- def merge_field_infos(*field_infos: FieldInfo, **overrides: Any) -> FieldInfo:
- """Merge `FieldInfo` instances keeping only explicitly set attributes.
-
- Later `FieldInfo` instances override earlier ones.
-
- Returns:
- FieldInfo: A merged FieldInfo instance.
- """
- if len(field_infos) == 1:
- # No merging necessary, but we still need to make a copy and apply the overrides
- field_info = field_infos[0]._copy()
- field_info._attributes_set.update(overrides)
-
- default_override = overrides.pop('default', PydanticUndefined)
- if default_override is Ellipsis:
- default_override = PydanticUndefined
- if default_override is not PydanticUndefined:
- field_info.default = default_override
-
- for k, v in overrides.items():
- setattr(field_info, k, v)
- return field_info # type: ignore
-
- merged_field_info_kwargs: dict[str, Any] = {}
- metadata = {}
- for field_info in field_infos:
- attributes_set = field_info._attributes_set.copy()
-
- try:
- json_schema_extra = attributes_set.pop('json_schema_extra')
- existing_json_schema_extra = merged_field_info_kwargs.get('json_schema_extra')
-
- if existing_json_schema_extra is None:
- merged_field_info_kwargs['json_schema_extra'] = json_schema_extra
- if isinstance(existing_json_schema_extra, dict):
- if isinstance(json_schema_extra, dict):
- merged_field_info_kwargs['json_schema_extra'] = {
- **existing_json_schema_extra,
- **json_schema_extra,
- }
- if callable(json_schema_extra):
- warn(
- 'Composing `dict` and `callable` type `json_schema_extra` is not supported.'
- 'The `callable` type is being ignored.'
- "If you'd like support for this behavior, please open an issue on pydantic.",
- PydanticJsonSchemaWarning,
- )
- elif callable(json_schema_extra):
- # if ever there's a case of a callable, we'll just keep the last json schema extra spec
- merged_field_info_kwargs['json_schema_extra'] = json_schema_extra
- except KeyError:
- pass
-
- # later FieldInfo instances override everything except json_schema_extra from earlier FieldInfo instances
- merged_field_info_kwargs.update(attributes_set)
-
- for x in field_info.metadata:
- if not isinstance(x, FieldInfo):
- metadata[type(x)] = x
-
- merged_field_info_kwargs.update(overrides)
- field_info = FieldInfo(**merged_field_info_kwargs)
- field_info.metadata = list(metadata.values())
- return field_info
-
- @staticmethod
- def _from_dataclass_field(dc_field: DataclassField[Any]) -> FieldInfo:
- """Return a new `FieldInfo` instance from a `dataclasses.Field` instance.
-
- Args:
- dc_field: The `dataclasses.Field` instance to convert.
-
- Returns:
- The corresponding `FieldInfo` instance.
-
- Raises:
- TypeError: If any of the `FieldInfo` kwargs does not match the `dataclass.Field` kwargs.
- """
- default = dc_field.default
- if default is dataclasses.MISSING:
- default = _Unset
-
- if dc_field.default_factory is dataclasses.MISSING:
- default_factory = _Unset
- else:
- default_factory = dc_field.default_factory
-
- # use the `Field` function so in correct kwargs raise the correct `TypeError`
- dc_field_metadata = {k: v for k, v in dc_field.metadata.items() if k in _FIELD_ARG_NAMES}
- return Field(default=default, default_factory=default_factory, repr=dc_field.repr, **dc_field_metadata) # pyright: ignore[reportCallIssue]
-
- @staticmethod
- def _collect_metadata(kwargs: dict[str, Any]) -> list[Any]:
- """Collect annotations from kwargs.
-
- Args:
- kwargs: Keyword arguments passed to the function.
-
- Returns:
- A list of metadata objects - a combination of `annotated_types.BaseMetadata` and
- `PydanticMetadata`.
- """
- metadata: list[Any] = []
- general_metadata = {}
- for key, value in list(kwargs.items()):
- try:
- marker = FieldInfo.metadata_lookup[key]
- except KeyError:
- continue
-
- del kwargs[key]
- if value is not None:
- if marker is None:
- general_metadata[key] = value
- else:
- metadata.append(marker(value))
- if general_metadata:
- metadata.append(_fields.pydantic_general_metadata(**general_metadata))
- return metadata
-
- def _copy(self) -> Self:
- copied = copy(self)
- for attr_name in ('metadata', '_attributes_set', '_qualifiers'):
- # Apply "deep-copy" behavior on collections attributes:
- value = getattr(copied, attr_name).copy()
- setattr(copied, attr_name, value)
-
- return copied
-
- @property
- def deprecation_message(self) -> str | None:
- """The deprecation message to be emitted, or `None` if not set."""
- if self.deprecated is None:
- return None
- if isinstance(self.deprecated, bool):
- return 'deprecated' if self.deprecated else None
- return self.deprecated if isinstance(self.deprecated, str) else self.deprecated.message
-
- @property
- def default_factory_takes_validated_data(self) -> bool | None:
- """Whether the provided default factory callable has a validated data parameter.
-
- Returns `None` if no default factory is set.
- """
- if self.default_factory is not None:
- return _fields.takes_validated_data_argument(self.default_factory)
-
- @overload
- def get_default(
- self, *, call_default_factory: Literal[True], validated_data: dict[str, Any] | None = None
- ) -> Any: ...
-
- @overload
- def get_default(self, *, call_default_factory: Literal[False] = ...) -> Any: ...
-
- def get_default(self, *, call_default_factory: bool = False, validated_data: dict[str, Any] | None = None) -> Any:
- """Get the default value.
-
- We expose an option for whether to call the default_factory (if present), as calling it may
- result in side effects that we want to avoid. However, there are times when it really should
- be called (namely, when instantiating a model via `model_construct`).
-
- Args:
- call_default_factory: Whether to call the default factory or not.
- validated_data: The already validated data to be passed to the default factory.
-
- Returns:
- The default value, calling the default factory if requested or `None` if not set.
- """
- if self.default_factory is None:
- return _utils.smart_deepcopy(self.default)
- elif call_default_factory:
- if self.default_factory_takes_validated_data:
- fac = cast('Callable[[dict[str, Any]], Any]', self.default_factory)
- if validated_data is None:
- raise ValueError(
- "The default factory requires the 'validated_data' argument, which was not provided when calling 'get_default'."
- )
- return fac(validated_data)
- else:
- fac = cast('Callable[[], Any]', self.default_factory)
- return fac()
- else:
- return None
-
- def is_required(self) -> bool:
- """Check if the field is required (i.e., does not have a default value or factory).
-
- Returns:
- `True` if the field is required, `False` otherwise.
- """
- return self.default is PydanticUndefined and self.default_factory is None
-
- def rebuild_annotation(self) -> Any:
- """Attempts to rebuild the original annotation for use in function signatures.
-
- If metadata is present, it adds it to the original annotation using
- `Annotated`. Otherwise, it returns the original annotation as-is.
-
- Note that because the metadata has been flattened, the original annotation
- may not be reconstructed exactly as originally provided, e.g. if the original
- type had unrecognized annotations, or was annotated with a call to `pydantic.Field`.
-
- Returns:
- The rebuilt annotation.
- """
- if not self.metadata:
- return self.annotation
- else:
- # Annotated arguments must be a tuple
- return Annotated[(self.annotation, *self.metadata)] # type: ignore
-
- def apply_typevars_map(
- self,
- typevars_map: Mapping[TypeVar, Any] | None,
- globalns: GlobalsNamespace | None = None,
- localns: MappingNamespace | None = None,
- ) -> None:
- """Apply a `typevars_map` to the annotation.
-
- This method is used when analyzing parametrized generic types to replace typevars with their concrete types.
-
- This method applies the `typevars_map` to the annotation in place.
-
- Args:
- typevars_map: A dictionary mapping type variables to their concrete types.
- globalns: The globals namespace to use during type annotation evaluation.
- localns: The locals namespace to use during type annotation evaluation.
-
- See Also:
- pydantic._internal._generics.replace_types is used for replacing the typevars with
- their concrete types.
- """
- annotation = _generics.replace_types(self.annotation, typevars_map)
- annotation, evaluated = _typing_extra.try_eval_type(annotation, globalns, localns)
- self.annotation = annotation
- if not evaluated:
- self._complete = False
- self._original_annotation = self.annotation
-
- def __repr_args__(self) -> ReprArgs:
- yield 'annotation', _repr.PlainRepr(_repr.display_as_type(self.annotation))
- yield 'required', self.is_required()
-
- for s in self.__slots__:
- # TODO: properly make use of the protocol (https://rich.readthedocs.io/en/stable/pretty.html#rich-repr-protocol)
- # By yielding a three-tuple:
- if s in (
- 'annotation',
- '_attributes_set',
- '_qualifiers',
- '_complete',
- '_original_assignment',
- '_original_annotation',
- ):
- continue
- elif s == 'metadata' and not self.metadata:
- continue
- elif s == 'repr' and self.repr is True:
- continue
- if s == 'frozen' and self.frozen is False:
- continue
- if s == 'validation_alias' and self.validation_alias == self.alias:
- continue
- if s == 'serialization_alias' and self.serialization_alias == self.alias:
- continue
- if s == 'default' and self.default is not PydanticUndefined:
- yield 'default', self.default
- elif s == 'default_factory' and self.default_factory is not None:
- yield 'default_factory', _repr.PlainRepr(_repr.display_as_type(self.default_factory))
- else:
- value = getattr(self, s)
- if value is not None and value is not PydanticUndefined:
- yield s, value
-
-
- class _EmptyKwargs(typing_extensions.TypedDict):
- """This class exists solely to ensure that type checking warns about passing `**extra` in `Field`."""
-
-
- _DefaultValues = {
- 'default': ...,
- 'default_factory': None,
- 'alias': None,
- 'alias_priority': None,
- 'validation_alias': None,
- 'serialization_alias': None,
- 'title': None,
- 'description': None,
- 'examples': None,
- 'exclude': None,
- 'discriminator': None,
- 'json_schema_extra': None,
- 'frozen': None,
- 'validate_default': None,
- 'repr': True,
- 'init': None,
- 'init_var': None,
- 'kw_only': None,
- 'pattern': None,
- 'strict': None,
- 'gt': None,
- 'ge': None,
- 'lt': None,
- 'le': None,
- 'multiple_of': None,
- 'allow_inf_nan': None,
- 'max_digits': None,
- 'decimal_places': None,
- 'min_length': None,
- 'max_length': None,
- 'coerce_numbers_to_str': None,
- }
-
-
- _T = TypeVar('_T')
-
-
- # NOTE: Actual return type is 'FieldInfo', but we want to help type checkers
- # to understand the magic that happens at runtime with the following overloads:
- @overload # type hint the return value as `Any` to avoid type checking regressions when using `...`.
- def Field(
- default: ellipsis, # noqa: F821 # TODO: use `_typing_extra.EllipsisType` when we drop Py3.9
- *,
- alias: str | None = _Unset,
- alias_priority: int | None = _Unset,
- validation_alias: str | AliasPath | AliasChoices | None = _Unset,
- serialization_alias: str | None = _Unset,
- title: str | None = _Unset,
- field_title_generator: Callable[[str, FieldInfo], str] | None = _Unset,
- description: str | None = _Unset,
- examples: list[Any] | None = _Unset,
- exclude: bool | None = _Unset,
- discriminator: str | types.Discriminator | None = _Unset,
- deprecated: Deprecated | str | bool | None = _Unset,
- json_schema_extra: JsonDict | Callable[[JsonDict], None] | None = _Unset,
- frozen: bool | None = _Unset,
- validate_default: bool | None = _Unset,
- repr: bool = _Unset,
- init: bool | None = _Unset,
- init_var: bool | None = _Unset,
- kw_only: bool | None = _Unset,
- pattern: str | typing.Pattern[str] | None = _Unset,
- strict: bool | None = _Unset,
- coerce_numbers_to_str: bool | None = _Unset,
- gt: annotated_types.SupportsGt | None = _Unset,
- ge: annotated_types.SupportsGe | None = _Unset,
- lt: annotated_types.SupportsLt | None = _Unset,
- le: annotated_types.SupportsLe | None = _Unset,
- multiple_of: float | None = _Unset,
- allow_inf_nan: bool | None = _Unset,
- max_digits: int | None = _Unset,
- decimal_places: int | None = _Unset,
- min_length: int | None = _Unset,
- max_length: int | None = _Unset,
- union_mode: Literal['smart', 'left_to_right'] = _Unset,
- fail_fast: bool | None = _Unset,
- **extra: Unpack[_EmptyKwargs],
- ) -> Any: ...
- @overload # `default` argument set
- def Field(
- default: _T,
- *,
- alias: str | None = _Unset,
- alias_priority: int | None = _Unset,
- validation_alias: str | AliasPath | AliasChoices | None = _Unset,
- serialization_alias: str | None = _Unset,
- title: str | None = _Unset,
- field_title_generator: Callable[[str, FieldInfo], str] | None = _Unset,
- description: str | None = _Unset,
- examples: list[Any] | None = _Unset,
- exclude: bool | None = _Unset,
- discriminator: str | types.Discriminator | None = _Unset,
- deprecated: Deprecated | str | bool | None = _Unset,
- json_schema_extra: JsonDict | Callable[[JsonDict], None] | None = _Unset,
- frozen: bool | None = _Unset,
- validate_default: bool | None = _Unset,
- repr: bool = _Unset,
- init: bool | None = _Unset,
- init_var: bool | None = _Unset,
- kw_only: bool | None = _Unset,
- pattern: str | typing.Pattern[str] | None = _Unset,
- strict: bool | None = _Unset,
- coerce_numbers_to_str: bool | None = _Unset,
- gt: annotated_types.SupportsGt | None = _Unset,
- ge: annotated_types.SupportsGe | None = _Unset,
- lt: annotated_types.SupportsLt | None = _Unset,
- le: annotated_types.SupportsLe | None = _Unset,
- multiple_of: float | None = _Unset,
- allow_inf_nan: bool | None = _Unset,
- max_digits: int | None = _Unset,
- decimal_places: int | None = _Unset,
- min_length: int | None = _Unset,
- max_length: int | None = _Unset,
- union_mode: Literal['smart', 'left_to_right'] = _Unset,
- fail_fast: bool | None = _Unset,
- **extra: Unpack[_EmptyKwargs],
- ) -> _T: ...
- @overload # `default_factory` argument set
- def Field(
- *,
- default_factory: Callable[[], _T] | Callable[[dict[str, Any]], _T],
- alias: str | None = _Unset,
- alias_priority: int | None = _Unset,
- validation_alias: str | AliasPath | AliasChoices | None = _Unset,
- serialization_alias: str | None = _Unset,
- title: str | None = _Unset,
- field_title_generator: Callable[[str, FieldInfo], str] | None = _Unset,
- description: str | None = _Unset,
- examples: list[Any] | None = _Unset,
- exclude: bool | None = _Unset,
- discriminator: str | types.Discriminator | None = _Unset,
- deprecated: Deprecated | str | bool | None = _Unset,
- json_schema_extra: JsonDict | Callable[[JsonDict], None] | None = _Unset,
- frozen: bool | None = _Unset,
- validate_default: bool | None = _Unset,
- repr: bool = _Unset,
- init: bool | None = _Unset,
- init_var: bool | None = _Unset,
- kw_only: bool | None = _Unset,
- pattern: str | typing.Pattern[str] | None = _Unset,
- strict: bool | None = _Unset,
- coerce_numbers_to_str: bool | None = _Unset,
- gt: annotated_types.SupportsGt | None = _Unset,
- ge: annotated_types.SupportsGe | None = _Unset,
- lt: annotated_types.SupportsLt | None = _Unset,
- le: annotated_types.SupportsLe | None = _Unset,
- multiple_of: float | None = _Unset,
- allow_inf_nan: bool | None = _Unset,
- max_digits: int | None = _Unset,
- decimal_places: int | None = _Unset,
- min_length: int | None = _Unset,
- max_length: int | None = _Unset,
- union_mode: Literal['smart', 'left_to_right'] = _Unset,
- fail_fast: bool | None = _Unset,
- **extra: Unpack[_EmptyKwargs],
- ) -> _T: ...
- @overload
- def Field( # No default set
- *,
- alias: str | None = _Unset,
- alias_priority: int | None = _Unset,
- validation_alias: str | AliasPath | AliasChoices | None = _Unset,
- serialization_alias: str | None = _Unset,
- title: str | None = _Unset,
- field_title_generator: Callable[[str, FieldInfo], str] | None = _Unset,
- description: str | None = _Unset,
- examples: list[Any] | None = _Unset,
- exclude: bool | None = _Unset,
- discriminator: str | types.Discriminator | None = _Unset,
- deprecated: Deprecated | str | bool | None = _Unset,
- json_schema_extra: JsonDict | Callable[[JsonDict], None] | None = _Unset,
- frozen: bool | None = _Unset,
- validate_default: bool | None = _Unset,
- repr: bool = _Unset,
- init: bool | None = _Unset,
- init_var: bool | None = _Unset,
- kw_only: bool | None = _Unset,
- pattern: str | typing.Pattern[str] | None = _Unset,
- strict: bool | None = _Unset,
- coerce_numbers_to_str: bool | None = _Unset,
- gt: annotated_types.SupportsGt | None = _Unset,
- ge: annotated_types.SupportsGe | None = _Unset,
- lt: annotated_types.SupportsLt | None = _Unset,
- le: annotated_types.SupportsLe | None = _Unset,
- multiple_of: float | None = _Unset,
- allow_inf_nan: bool | None = _Unset,
- max_digits: int | None = _Unset,
- decimal_places: int | None = _Unset,
- min_length: int | None = _Unset,
- max_length: int | None = _Unset,
- union_mode: Literal['smart', 'left_to_right'] = _Unset,
- fail_fast: bool | None = _Unset,
- **extra: Unpack[_EmptyKwargs],
- ) -> Any: ...
- def Field( # noqa: C901
- default: Any = PydanticUndefined,
- *,
- default_factory: Callable[[], Any] | Callable[[dict[str, Any]], Any] | None = _Unset,
- alias: str | None = _Unset,
- alias_priority: int | None = _Unset,
- validation_alias: str | AliasPath | AliasChoices | None = _Unset,
- serialization_alias: str | None = _Unset,
- title: str | None = _Unset,
- field_title_generator: Callable[[str, FieldInfo], str] | None = _Unset,
- description: str | None = _Unset,
- examples: list[Any] | None = _Unset,
- exclude: bool | None = _Unset,
- discriminator: str | types.Discriminator | None = _Unset,
- deprecated: Deprecated | str | bool | None = _Unset,
- json_schema_extra: JsonDict | Callable[[JsonDict], None] | None = _Unset,
- frozen: bool | None = _Unset,
- validate_default: bool | None = _Unset,
- repr: bool = _Unset,
- init: bool | None = _Unset,
- init_var: bool | None = _Unset,
- kw_only: bool | None = _Unset,
- pattern: str | typing.Pattern[str] | None = _Unset,
- strict: bool | None = _Unset,
- coerce_numbers_to_str: bool | None = _Unset,
- gt: annotated_types.SupportsGt | None = _Unset,
- ge: annotated_types.SupportsGe | None = _Unset,
- lt: annotated_types.SupportsLt | None = _Unset,
- le: annotated_types.SupportsLe | None = _Unset,
- multiple_of: float | None = _Unset,
- allow_inf_nan: bool | None = _Unset,
- max_digits: int | None = _Unset,
- decimal_places: int | None = _Unset,
- min_length: int | None = _Unset,
- max_length: int | None = _Unset,
- union_mode: Literal['smart', 'left_to_right'] = _Unset,
- fail_fast: bool | None = _Unset,
- **extra: Unpack[_EmptyKwargs],
- ) -> Any:
- """!!! abstract "Usage Documentation"
- [Fields](../concepts/fields.md)
-
- Create a field for objects that can be configured.
-
- Used to provide extra information about a field, either for the model schema or complex validation. Some arguments
- apply only to number fields (`int`, `float`, `Decimal`) and some apply only to `str`.
-
- Note:
- - Any `_Unset` objects will be replaced by the corresponding value defined in the `_DefaultValues` dictionary. If a key for the `_Unset` object is not found in the `_DefaultValues` dictionary, it will default to `None`
-
- Args:
- default: Default value if the field is not set.
- default_factory: A callable to generate the default value. The callable can either take 0 arguments
- (in which case it is called as is) or a single argument containing the already validated data.
- alias: The name to use for the attribute when validating or serializing by alias.
- This is often used for things like converting between snake and camel case.
- alias_priority: Priority of the alias. This affects whether an alias generator is used.
- validation_alias: Like `alias`, but only affects validation, not serialization.
- serialization_alias: Like `alias`, but only affects serialization, not validation.
- title: Human-readable title.
- field_title_generator: A callable that takes a field name and returns title for it.
- description: Human-readable description.
- examples: Example values for this field.
- exclude: Whether to exclude the field from the model serialization.
- discriminator: Field name or Discriminator for discriminating the type in a tagged union.
- deprecated: A deprecation message, an instance of `warnings.deprecated` or the `typing_extensions.deprecated` backport,
- or a boolean. If `True`, a default deprecation message will be emitted when accessing the field.
- json_schema_extra: A dict or callable to provide extra JSON schema properties.
- frozen: Whether the field is frozen. If true, attempts to change the value on an instance will raise an error.
- validate_default: If `True`, apply validation to the default value every time you create an instance.
- Otherwise, for performance reasons, the default value of the field is trusted and not validated.
- repr: A boolean indicating whether to include the field in the `__repr__` output.
- init: Whether the field should be included in the constructor of the dataclass.
- (Only applies to dataclasses.)
- init_var: Whether the field should _only_ be included in the constructor of the dataclass.
- (Only applies to dataclasses.)
- kw_only: Whether the field should be a keyword-only argument in the constructor of the dataclass.
- (Only applies to dataclasses.)
- coerce_numbers_to_str: Whether to enable coercion of any `Number` type to `str` (not applicable in `strict` mode).
- strict: If `True`, strict validation is applied to the field.
- See [Strict Mode](../concepts/strict_mode.md) for details.
- gt: Greater than. If set, value must be greater than this. Only applicable to numbers.
- ge: Greater than or equal. If set, value must be greater than or equal to this. Only applicable to numbers.
- lt: Less than. If set, value must be less than this. Only applicable to numbers.
- le: Less than or equal. If set, value must be less than or equal to this. Only applicable to numbers.
- multiple_of: Value must be a multiple of this. Only applicable to numbers.
- min_length: Minimum length for iterables.
- max_length: Maximum length for iterables.
- pattern: Pattern for strings (a regular expression).
- allow_inf_nan: Allow `inf`, `-inf`, `nan`. Only applicable to float and [`Decimal`][decimal.Decimal] numbers.
- max_digits: Maximum number of allow digits for strings.
- decimal_places: Maximum number of decimal places allowed for numbers.
- union_mode: The strategy to apply when validating a union. Can be `smart` (the default), or `left_to_right`.
- See [Union Mode](../concepts/unions.md#union-modes) for details.
- fail_fast: If `True`, validation will stop on the first error. If `False`, all validation errors will be collected.
- This option can be applied only to iterable types (list, tuple, set, and frozenset).
- extra: (Deprecated) Extra fields that will be included in the JSON schema.
-
- !!! warning Deprecated
- The `extra` kwargs is deprecated. Use `json_schema_extra` instead.
-
- Returns:
- A new [`FieldInfo`][pydantic.fields.FieldInfo]. The return annotation is `Any` so `Field` can be used on
- type-annotated fields without causing a type error.
- """
- # Check deprecated and removed params from V1. This logic should eventually be removed.
- const = extra.pop('const', None) # type: ignore
- if const is not None:
- raise PydanticUserError('`const` is removed, use `Literal` instead', code='removed-kwargs')
-
- min_items = extra.pop('min_items', None) # type: ignore
- if min_items is not None:
- warn('`min_items` is deprecated and will be removed, use `min_length` instead', DeprecationWarning)
- if min_length in (None, _Unset):
- min_length = min_items # type: ignore
-
- max_items = extra.pop('max_items', None) # type: ignore
- if max_items is not None:
- warn('`max_items` is deprecated and will be removed, use `max_length` instead', DeprecationWarning)
- if max_length in (None, _Unset):
- max_length = max_items # type: ignore
-
- unique_items = extra.pop('unique_items', None) # type: ignore
- if unique_items is not None:
- raise PydanticUserError(
- (
- '`unique_items` is removed, use `Set` instead'
- '(this feature is discussed in https://github.com/pydantic/pydantic-core/issues/296)'
- ),
- code='removed-kwargs',
- )
-
- allow_mutation = extra.pop('allow_mutation', None) # type: ignore
- if allow_mutation is not None:
- warn('`allow_mutation` is deprecated and will be removed. use `frozen` instead', DeprecationWarning)
- if allow_mutation is False:
- frozen = True
-
- regex = extra.pop('regex', None) # type: ignore
- if regex is not None:
- raise PydanticUserError('`regex` is removed. use `pattern` instead', code='removed-kwargs')
-
- if extra:
- warn(
- 'Using extra keyword arguments on `Field` is deprecated and will be removed.'
- ' Use `json_schema_extra` instead.'
- f' (Extra keys: {", ".join(k.__repr__() for k in extra.keys())})',
- DeprecationWarning,
- )
- if not json_schema_extra or json_schema_extra is _Unset:
- json_schema_extra = extra # type: ignore
-
- if (
- validation_alias
- and validation_alias is not _Unset
- and not isinstance(validation_alias, (str, AliasChoices, AliasPath))
- ):
- raise TypeError('Invalid `validation_alias` type. it should be `str`, `AliasChoices`, or `AliasPath`')
-
- if serialization_alias in (_Unset, None) and isinstance(alias, str):
- serialization_alias = alias
-
- if validation_alias in (_Unset, None):
- validation_alias = alias
-
- include = extra.pop('include', None) # type: ignore
- if include is not None:
- warn('`include` is deprecated and does nothing. It will be removed, use `exclude` instead', DeprecationWarning)
-
- return FieldInfo.from_field(
- default,
- default_factory=default_factory,
- alias=alias,
- alias_priority=alias_priority,
- validation_alias=validation_alias,
- serialization_alias=serialization_alias,
- title=title,
- field_title_generator=field_title_generator,
- description=description,
- examples=examples,
- exclude=exclude,
- discriminator=discriminator,
- deprecated=deprecated,
- json_schema_extra=json_schema_extra,
- frozen=frozen,
- pattern=pattern,
- validate_default=validate_default,
- repr=repr,
- init=init,
- init_var=init_var,
- kw_only=kw_only,
- coerce_numbers_to_str=coerce_numbers_to_str,
- strict=strict,
- gt=gt,
- ge=ge,
- lt=lt,
- le=le,
- multiple_of=multiple_of,
- min_length=min_length,
- max_length=max_length,
- allow_inf_nan=allow_inf_nan,
- max_digits=max_digits,
- decimal_places=decimal_places,
- union_mode=union_mode,
- fail_fast=fail_fast,
- )
-
-
- _FIELD_ARG_NAMES = set(inspect.signature(Field).parameters)
- _FIELD_ARG_NAMES.remove('extra') # do not include the varkwargs parameter
-
-
- class ModelPrivateAttr(_repr.Representation):
- """A descriptor for private attributes in class models.
-
- !!! warning
- You generally shouldn't be creating `ModelPrivateAttr` instances directly, instead use
- `pydantic.fields.PrivateAttr`. (This is similar to `FieldInfo` vs. `Field`.)
-
- Attributes:
- default: The default value of the attribute if not provided.
- default_factory: A callable function that generates the default value of the
- attribute if not provided.
- """
-
- __slots__ = ('default', 'default_factory')
-
- def __init__(
- self, default: Any = PydanticUndefined, *, default_factory: typing.Callable[[], Any] | None = None
- ) -> None:
- if default is Ellipsis:
- self.default = PydanticUndefined
- else:
- self.default = default
- self.default_factory = default_factory
-
- if not typing.TYPE_CHECKING:
- # We put `__getattr__` in a non-TYPE_CHECKING block because otherwise, mypy allows arbitrary attribute access
-
- def __getattr__(self, item: str) -> Any:
- """This function improves compatibility with custom descriptors by ensuring delegation happens
- as expected when the default value of a private attribute is a descriptor.
- """
- if item in {'__get__', '__set__', '__delete__'}:
- if hasattr(self.default, item):
- return getattr(self.default, item)
- raise AttributeError(f'{type(self).__name__!r} object has no attribute {item!r}')
-
- def __set_name__(self, cls: type[Any], name: str) -> None:
- """Preserve `__set_name__` protocol defined in https://peps.python.org/pep-0487."""
- default = self.default
- if default is PydanticUndefined:
- return
- set_name = getattr(default, '__set_name__', None)
- if callable(set_name):
- set_name(cls, name)
-
- def get_default(self) -> Any:
- """Retrieve the default value of the object.
-
- If `self.default_factory` is `None`, the method will return a deep copy of the `self.default` object.
-
- If `self.default_factory` is not `None`, it will call `self.default_factory` and return the value returned.
-
- Returns:
- The default value of the object.
- """
- return _utils.smart_deepcopy(self.default) if self.default_factory is None else self.default_factory()
-
- def __eq__(self, other: Any) -> bool:
- return isinstance(other, self.__class__) and (self.default, self.default_factory) == (
- other.default,
- other.default_factory,
- )
-
-
- # NOTE: Actual return type is 'ModelPrivateAttr', but we want to help type checkers
- # to understand the magic that happens at runtime.
- @overload # `default` argument set
- def PrivateAttr(
- default: _T,
- *,
- init: Literal[False] = False,
- ) -> _T: ...
- @overload # `default_factory` argument set
- def PrivateAttr(
- *,
- default_factory: Callable[[], _T],
- init: Literal[False] = False,
- ) -> _T: ...
- @overload # No default set
- def PrivateAttr(
- *,
- init: Literal[False] = False,
- ) -> Any: ...
- def PrivateAttr(
- default: Any = PydanticUndefined,
- *,
- default_factory: Callable[[], Any] | None = None,
- init: Literal[False] = False,
- ) -> Any:
- """!!! abstract "Usage Documentation"
- [Private Model Attributes](../concepts/models.md#private-model-attributes)
-
- Indicates that an attribute is intended for private use and not handled during normal validation/serialization.
-
- Private attributes are not validated by Pydantic, so it's up to you to ensure they are used in a type-safe manner.
-
- Private attributes are stored in `__private_attributes__` on the model.
-
- Args:
- default: The attribute's default value. Defaults to Undefined.
- default_factory: Callable that will be
- called when a default value is needed for this attribute.
- If both `default` and `default_factory` are set, an error will be raised.
- init: Whether the attribute should be included in the constructor of the dataclass. Always `False`.
-
- Returns:
- An instance of [`ModelPrivateAttr`][pydantic.fields.ModelPrivateAttr] class.
-
- Raises:
- ValueError: If both `default` and `default_factory` are set.
- """
- if default is not PydanticUndefined and default_factory is not None:
- raise TypeError('cannot specify both default and default_factory')
-
- return ModelPrivateAttr(
- default,
- default_factory=default_factory,
- )
-
-
- @dataclasses.dataclass(**_internal_dataclass.slots_true)
- class ComputedFieldInfo:
- """A container for data from `@computed_field` so that we can access it while building the pydantic-core schema.
-
- Attributes:
- decorator_repr: A class variable representing the decorator string, '@computed_field'.
- wrapped_property: The wrapped computed field property.
- return_type: The type of the computed field property's return value.
- alias: The alias of the property to be used during serialization.
- alias_priority: The priority of the alias. This affects whether an alias generator is used.
- title: Title of the computed field to include in the serialization JSON schema.
- field_title_generator: A callable that takes a field name and returns title for it.
- description: Description of the computed field to include in the serialization JSON schema.
- deprecated: A deprecation message, an instance of `warnings.deprecated` or the `typing_extensions.deprecated` backport,
- or a boolean. If `True`, a default deprecation message will be emitted when accessing the field.
- examples: Example values of the computed field to include in the serialization JSON schema.
- json_schema_extra: A dict or callable to provide extra JSON schema properties.
- repr: A boolean indicating whether to include the field in the __repr__ output.
- """
-
- decorator_repr: ClassVar[str] = '@computed_field'
- wrapped_property: property
- return_type: Any
- alias: str | None
- alias_priority: int | None
- title: str | None
- field_title_generator: typing.Callable[[str, ComputedFieldInfo], str] | None
- description: str | None
- deprecated: Deprecated | str | bool | None
- examples: list[Any] | None
- json_schema_extra: JsonDict | typing.Callable[[JsonDict], None] | None
- repr: bool
-
- @property
- def deprecation_message(self) -> str | None:
- """The deprecation message to be emitted, or `None` if not set."""
- if self.deprecated is None:
- return None
- if isinstance(self.deprecated, bool):
- return 'deprecated' if self.deprecated else None
- return self.deprecated if isinstance(self.deprecated, str) else self.deprecated.message
-
-
- def _wrapped_property_is_private(property_: cached_property | property) -> bool: # type: ignore
- """Returns true if provided property is private, False otherwise."""
- wrapped_name: str = ''
-
- if isinstance(property_, property):
- wrapped_name = getattr(property_.fget, '__name__', '')
- elif isinstance(property_, cached_property): # type: ignore
- wrapped_name = getattr(property_.func, '__name__', '') # type: ignore
-
- return wrapped_name.startswith('_') and not wrapped_name.startswith('__')
-
-
- # this should really be `property[T], cached_property[T]` but property is not generic unlike cached_property
- # See https://github.com/python/typing/issues/985 and linked issues
- PropertyT = typing.TypeVar('PropertyT')
-
-
- @typing.overload
- def computed_field(func: PropertyT, /) -> PropertyT: ...
-
-
- @typing.overload
- def computed_field(
- *,
- alias: str | None = None,
- alias_priority: int | None = None,
- title: str | None = None,
- field_title_generator: typing.Callable[[str, ComputedFieldInfo], str] | None = None,
- description: str | None = None,
- deprecated: Deprecated | str | bool | None = None,
- examples: list[Any] | None = None,
- json_schema_extra: JsonDict | typing.Callable[[JsonDict], None] | None = None,
- repr: bool = True,
- return_type: Any = PydanticUndefined,
- ) -> typing.Callable[[PropertyT], PropertyT]: ...
-
-
- def computed_field(
- func: PropertyT | None = None,
- /,
- *,
- alias: str | None = None,
- alias_priority: int | None = None,
- title: str | None = None,
- field_title_generator: typing.Callable[[str, ComputedFieldInfo], str] | None = None,
- description: str | None = None,
- deprecated: Deprecated | str | bool | None = None,
- examples: list[Any] | None = None,
- json_schema_extra: JsonDict | typing.Callable[[JsonDict], None] | None = None,
- repr: bool | None = None,
- return_type: Any = PydanticUndefined,
- ) -> PropertyT | typing.Callable[[PropertyT], PropertyT]:
- """!!! abstract "Usage Documentation"
- [The `computed_field` decorator](../concepts/fields.md#the-computed_field-decorator)
-
- Decorator to include `property` and `cached_property` when serializing models or dataclasses.
-
- This is useful for fields that are computed from other fields, or for fields that are expensive to compute and should be cached.
-
- ```python
- from pydantic import BaseModel, computed_field
-
- class Rectangle(BaseModel):
- width: int
- length: int
-
- @computed_field
- @property
- def area(self) -> int:
- return self.width * self.length
-
- print(Rectangle(width=3, length=2).model_dump())
- #> {'width': 3, 'length': 2, 'area': 6}
- ```
-
- If applied to functions not yet decorated with `@property` or `@cached_property`, the function is
- automatically wrapped with `property`. Although this is more concise, you will lose IntelliSense in your IDE,
- and confuse static type checkers, thus explicit use of `@property` is recommended.
-
- !!! warning "Mypy Warning"
- Even with the `@property` or `@cached_property` applied to your function before `@computed_field`,
- mypy may throw a `Decorated property not supported` error.
- See [mypy issue #1362](https://github.com/python/mypy/issues/1362), for more information.
- To avoid this error message, add `# type: ignore[prop-decorator]` to the `@computed_field` line.
-
- [pyright](https://github.com/microsoft/pyright) supports `@computed_field` without error.
-
- ```python
- import random
-
- from pydantic import BaseModel, computed_field
-
- class Square(BaseModel):
- width: float
-
- @computed_field
- def area(self) -> float: # converted to a `property` by `computed_field`
- return round(self.width**2, 2)
-
- @area.setter
- def area(self, new_area: float) -> None:
- self.width = new_area**0.5
-
- @computed_field(alias='the magic number', repr=False)
- def random_number(self) -> int:
- return random.randint(0, 1_000)
-
- square = Square(width=1.3)
-
- # `random_number` does not appear in representation
- print(repr(square))
- #> Square(width=1.3, area=1.69)
-
- print(square.random_number)
- #> 3
-
- square.area = 4
-
- print(square.model_dump_json(by_alias=True))
- #> {"width":2.0,"area":4.0,"the magic number":3}
- ```
-
- !!! warning "Overriding with `computed_field`"
- You can't override a field from a parent class with a `computed_field` in the child class.
- `mypy` complains about this behavior if allowed, and `dataclasses` doesn't allow this pattern either.
- See the example below:
-
- ```python
- from pydantic import BaseModel, computed_field
-
- class Parent(BaseModel):
- a: str
-
- try:
-
- class Child(Parent):
- @computed_field
- @property
- def a(self) -> str:
- return 'new a'
-
- except TypeError as e:
- print(e)
- '''
- Field 'a' of class 'Child' overrides symbol of same name in a parent class. This override with a computed_field is incompatible.
- '''
- ```
-
- Private properties decorated with `@computed_field` have `repr=False` by default.
-
- ```python
- from functools import cached_property
-
- from pydantic import BaseModel, computed_field
-
- class Model(BaseModel):
- foo: int
-
- @computed_field
- @cached_property
- def _private_cached_property(self) -> int:
- return -self.foo
-
- @computed_field
- @property
- def _private_property(self) -> int:
- return -self.foo
-
- m = Model(foo=1)
- print(repr(m))
- #> Model(foo=1)
- ```
-
- Args:
- func: the function to wrap.
- alias: alias to use when serializing this computed field, only used when `by_alias=True`
- alias_priority: priority of the alias. This affects whether an alias generator is used
- title: Title to use when including this computed field in JSON Schema
- field_title_generator: A callable that takes a field name and returns title for it.
- description: Description to use when including this computed field in JSON Schema, defaults to the function's
- docstring
- deprecated: A deprecation message (or an instance of `warnings.deprecated` or the `typing_extensions.deprecated` backport).
- to be emitted when accessing the field. Or a boolean. This will automatically be set if the property is decorated with the
- `deprecated` decorator.
- examples: Example values to use when including this computed field in JSON Schema
- json_schema_extra: A dict or callable to provide extra JSON schema properties.
- repr: whether to include this computed field in model repr.
- Default is `False` for private properties and `True` for public properties.
- return_type: optional return for serialization logic to expect when serializing to JSON, if included
- this must be correct, otherwise a `TypeError` is raised.
- If you don't include a return type Any is used, which does runtime introspection to handle arbitrary
- objects.
-
- Returns:
- A proxy wrapper for the property.
- """
-
- def dec(f: Any) -> Any:
- nonlocal description, deprecated, return_type, alias_priority
- unwrapped = _decorators.unwrap_wrapped_function(f)
-
- if description is None and unwrapped.__doc__:
- description = inspect.cleandoc(unwrapped.__doc__)
-
- if deprecated is None and hasattr(unwrapped, '__deprecated__'):
- deprecated = unwrapped.__deprecated__
-
- # if the function isn't already decorated with `@property` (or another descriptor), then we wrap it now
- f = _decorators.ensure_property(f)
- alias_priority = (alias_priority or 2) if alias is not None else None
-
- if repr is None:
- repr_: bool = not _wrapped_property_is_private(property_=f)
- else:
- repr_ = repr
-
- dec_info = ComputedFieldInfo(
- f,
- return_type,
- alias,
- alias_priority,
- title,
- field_title_generator,
- description,
- deprecated,
- examples,
- json_schema_extra,
- repr_,
- )
- return _decorators.PydanticDescriptorProxy(f, dec_info)
-
- if func is None:
- return dec
- else:
- return dec(func)
|