Field

Usage of Field to create a FieldInfo object, providing additional information about a field for validation and serialization.

def Field(
    default_factory: Callable[[], Any] | Callable[[dict[str, Any]], Any],
    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,
    exclude_if: Callable[[Any], 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: Literal[True],
    repr: bool,
    init: bool | None,
    init_var: bool | None,
    kw_only: bool | None,
    pattern: str | re.Pattern[str] | None,
    strict: bool | None,
    coerce_numbers_to_str: 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,
    allow_inf_nan: bool | None,
    max_digits: int | None,
    decimal_places: int | None,
    min_length: int | None,
    max_length: int | None,
    union_mode: Literal['smart', 'left_to_right'],
    fail_fast: bool | None
) - > Any

Configures metadata and validation constraints for a Pydantic model field. Use this to define default values, aliases, schema information, and numeric or string constraints.

Parameters

Name	Type	Description
default_factory	`Callable[[], Any]	Callable[[dict[str, Any]], Any]`
alias	`str	None`
alias_priority	`int	None`
validation_alias	`str	AliasPath
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`
exclude_if	`Callable[[Any], bool]	None`
discriminator	`str	types.Discriminator
deprecated	`Deprecated	str
json_schema_extra	`JsonDict	Callable[[JsonDict], None]
frozen	`bool	None`
validate_default	`Literal[True]`	Forces Pydantic to run validation logic on the default value or default_factory result.
repr	`bool`	Determines if the field should be included in the string representation of the model.
init	`bool	None`
init_var	`bool	None`
kw_only	`bool	None`
pattern	`str	re.Pattern[str]
strict	`bool	None`
coerce_numbers_to_str	`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`
allow_inf_nan	`bool	None`
max_digits	`int	None`
decimal_places	`int	None`
min_length	`int	None`
max_length	`int	None`
union_mode	`Literal['smart', 'left_to_right']`	Controls how Pydantic attempts to match data against types in a Union.
fail_fast	`bool	None`

Returns

Type	Description
`Any`	A FieldInfo instance that Pydantic uses to define the field's behavior and schema.

Parameters​

Returns​

Parameters

Returns