pydantic.fields
Defining fields on models.
usage docs: https://docs.pydantic.dev/dev-v2/usage/fields#aliaspath-and-aliaschoices
A data class used by validation_alias as a convenience to create aliases.
A list containing a string or AliasPath.
Type: list[str | AliasPath]
def convert_to_aliases() -> list[list[str | int]]
Converts arguments to a list of lists containing string or integer aliases.
list[list[str | int]] — The list of aliases.
usage docs: https://docs.pydantic.dev/dev-v2/usage/fields#aliaspath-and-aliaschoices
A data class used by validation_alias as a convenience to create aliases.
A list of string or integer aliases.
Type: list[int | str]
def convert_to_aliases() -> list[str | int]
Converts arguments to a list of string or integer aliases.
list[str | int] — The list of aliases.
A container for data from @computed_field so that we can access it while building the pydantic-core schema.
A class variable representing the decorator string, ‘@computed_field’.
Type: str
The wrapped computed field property.
Type: property
The type of the computed field property’s return value.
Type: Any
The alias of the property to be used during encoding and decoding.
Type: str | None
priority of the alias. This affects whether an alias generator is used
Type: int | None
Title of the computed field as in OpenAPI document, should be a short summary.
Type: str | None
Description of the computed field as in OpenAPI document.
Type: str | None
A boolean indicating whether or not to include the field in the repr output.
Type: bool
Bases: Representation
This class holds information about a field.
FieldInfo is used for any field definition regardless of whether the Field() function is explicitly used.
The type annotation of the field.
Type: type[Any] | None
The default value of the field.
Type: Any
The factory function used to construct the default for the field.
Type: typing.Callable[[], Any] | None
The alias name of the field.
Type: str | None
The priority of the field’s alias.
Type: int | None
The validation alias name of the field.
Type: str | AliasPath | AliasChoices | None
The serialization alias name of the field.
Type: str | None
The title of the field.
Type: str | None
The description of the field.
Type: str | None
List of examples of the field.
Type: list[Any] | None
Whether to exclude the field from the model schema.
Type: bool | None
Whether to include the field in the model schema.
Type: bool | None
Field name for discriminating the type in a tagged union.
Type: str | None
Dictionary of extra JSON schema properties.
Type: dict[str, Any] | None
Whether the field is frozen.
Type: bool | None
Whether to validate the default value of the field.
Type: bool | None
Whether to include the field in representation of the model.
Type: bool
Whether the field should be included in the constructor of the dataclass.
Type: bool | None
Whether the field should be a keyword-only argument in the constructor of the dataclass.
Type: bool | None
List of metadata constraints.
Type: list[Any]
def apply_typevars_map(
typevars_map: dict[Any, Any] | None,
types_namespace: dict[str, Any] | 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.
None
A dictionary mapping type variables to their concrete types.
A dictionary containing related types to the annotated type.
@classmethod
def from_annotated_attribute(
cls,
annotation: type[Any],
default: Any,
) -> typing_extensions.Self
Create FieldInfo from an annotation with a default value.
typing_extensions.Self — A field object with the passed values.
The type annotation of the field.
The default value of the field.
@classmethod
def from_annotation(cls, annotation: type[Any]) -> typing_extensions.Self
Creates a FieldInfo instance from a bare annotation.
typing_extensions.Self — An instance of the field metadata.
An annotation object.
@classmethod
def from_field(
cls,
default: Any = PydanticUndefined,
kwargs: Unpack[_FromFieldInfoInputs] = {},
) -> typing_extensions.Self
Create a new FieldInfo object with the Field function.
typing_extensions.Self — A new FieldInfo object with the given parameters.
The default value for the field. Defaults to Undefined.
Additional arguments dictionary.
TypeError— If ‘annotation’ is passed as a keyword argument.
def get_default(call_default_factory: bool = False) -> 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).
Any — The default value, calling the default factory if requested or None if not set.
Whether to call the default_factory or not. Defaults to False.
def is_required() -> bool
Check if the argument is required.
bool — True if the argument is required, False otherwise.
@staticmethod
def merge_field_infos(field_infos: FieldInfo = (), overrides: Any = {}) -> FieldInfo
Merge FieldInfo instances keeping only explicitly set attributes.
FieldInfo — A merged FieldInfo instance.
def rebuild_annotation() -> Any
Rebuilds the original annotation for use in function signatures.
If metadata is present, it adds it to the original annotation using an
AnnotatedAlias. Otherwise, it returns the original annotation as is.
Any — The rebuilt annotation.
Bases: Representation
A descriptor for private attributes in class models.
The default value of the attribute if not provided.
A callable function that generates the default value of the attribute if not provided.
def get_default() -> 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.
Any — The default value of the object.
def computed_field(
return_type: Any = PydanticUndefined,
alias: str | None = None,
alias_priority: int | None = None,
title: str | None = None,
description: str | None = None,
repr: bool = True,
) -> typing.Callable[[PropertyT], PropertyT]
def computed_field(__func: PropertyT) -> PropertyT
Decorator to include property and cached_property when serializing models.
If applied to functions not yet decorated with @property or @cached_property, the function is
automatically wrapped with property.
See Computed Fields for more details.
PropertyT | typing.Callable[[PropertyT], PropertyT] — A proxy wrapper for the property.
the function to wrap.
alias to use when serializing this computed field, only used when by_alias=True
priority of the alias. This affects whether an alias generator is used
Title to used when including this computed field in JSON Schema, currently unused waiting for #4697
Description to used when including this computed field in JSON Schema, defaults to the functions docstring, currently unused waiting for #4697
whether to include this computed field in model repr
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.
def Field(
default: Any = PydanticUndefined,
default_factory: typing.Callable[[], 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,
description: str | None = _Unset,
examples: list[Any] | None = _Unset,
exclude: bool | None = _Unset,
include: bool | None = _Unset,
discriminator: str | None = _Unset,
json_schema_extra: dict[str, Any] | None = _Unset,
frozen: bool | None = _Unset,
validate_default: bool | None = _Unset,
repr: bool = _Unset,
init_var: bool | None = _Unset,
kw_only: bool | None = _Unset,
pattern: str | None = _Unset,
strict: bool | None = _Unset,
gt: float | None = _Unset,
ge: float | None = _Unset,
lt: float | None = _Unset,
le: float | 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,
extra: Unpack[_EmptyKwargs] = {},
) -> Any
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.
Any — The generated FieldInfo object
Default value if the field is not set.
A callable to generate the default value, such as :func:~datetime.utcnow.
An alternative name for the attribute.
Priority of the alias. This affects whether an alias generator is used.
validation_alias : str | AliasPath | AliasChoices | None Default: _Unset
‘Whitelist’ validation step. The field will be the single one allowed by the alias or set of aliases defined.
‘Blacklist’ validation step. The vanilla field will be the single one of the alias’ or set of aliases’ fields and all the other fields will be ignored at serialization time.
Human-readable title.
Human-readable description.
Example values for this field.
Whether to exclude the field from the model schema.
Whether to include the field in the model schema.
Field name for discriminating the type in a tagged union.
Any additional JSON schema data for the schema property.
Whether the field is frozen.
Run validation that isn’t only checking existence of defaults. True by default.
A boolean indicating whether to include the field in the __repr__ output.
Whether the field should be included in the constructor of the dataclass.
Whether the field should be a keyword-only argument in the constructor of the dataclass.
If True, strict validation is applied to the field.
See Strict Mode for details.
Greater than. If set, value must be greater than this. Only applicable to numbers.
Greater than or equal. If set, value must be greater than or equal to this. Only applicable to numbers.
Less than. If set, value must be less than this. Only applicable to numbers.
Less than or equal. If set, value must be less than or equal to this. Only applicable to numbers.
Value must be a multiple of this. Only applicable to numbers.
Minimum length for strings.
Maximum length for strings.
Pattern for strings.
Allow inf, -inf, nan. Only applicable to numbers.
Maximum number of allow digits for strings.
Maximum number of decimal places allowed for numbers.
Include extra fields used by the JSON schema.
def PrivateAttr(
default: Any = PydanticUndefined,
default_factory: typing.Callable[[], Any] | None = None,
) -> Any
Indicates that attribute is only used internally and never mixed with regular fields.
Private attributes are not checked by Pydantic, so it’s up to you to maintain their accuracy.
Private attributes are stored in __private_attributes__ on the model.
Any — An instance of ModelPrivateAttr class.
The attribute’s default value. Defaults to Undefined.
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.
ValueError— If bothdefaultanddefault_factoryare set.