Class AfterValidator

pydantic/functional_validators.py:29–86

!!! abstract "Usage Documentation" [field *after* validators](../concepts/validators.md#field-after-validator) A metadata class that indicates that a validation should be applied **after** the inner validation logic. Attributes: func: The validator function. Example:

@dataclasses.dataclass(frozen=True, **_internal_dataclass.slots_true)
class AfterValidator:
    class="st">""class="st">"!!! abstract "Usage Documentation"
        [field *after* validators](../concepts/validators.mdclass="cm">#field-after-validator)

    A metadata class that indicates that a validation should be applied **after** the inner validation logic.

    Attributes:
        func: The validator function.

    Example:
        ```python
        from typing import Annotated

        from pydantic import AfterValidator, BaseModel, ValidationError

        MyInt = Annotated[int, AfterValidator(lambda v: v + 1)]

        class Model(BaseModel):
            a: MyInt

        print(Model(a=1).a)
        class="cm">#> 2

        try:
            Model(a=&class="cm">#x27;a')
        except ValidationError as e:
            print(e.json(indent=2))
            &class="cm">#x27;class="st">''
            [
              {
                class="st">"type": class="st">"int_parsing",
                class="st">"loc": [
                  class="st">"a"
                ],
                class="st">"msg": class="st">"Input should be a valid integer, unable to parse string as an integer",
                class="st">"input": class="st">"a",
                class="st">"url": class="st">"https://errors.pydantic.dev/2/v/int_parsing"
              }
            ]
            &class="cm">#x27;class="st">''
        ```
    class="st">"""

    func: core_schema.NoInfoValidatorFunction | core_schema.WithInfoValidatorFunction

    def __get_pydantic_core_schema__(self, source_type: Any, handler: GetCoreSchemaHandler) -> core_schema.CoreSchema:
        schema = handler(source_type)
        info_arg = _inspect_validator(self.func, mode=&class="cm">#x27;afterclass="st">', type='field')
        if info_arg:
            func = cast(core_schema.WithInfoValidatorFunction, self.func)
            return core_schema.with_info_after_validator_function(func, schema=schema)
        else:
            func = cast(core_schema.NoInfoValidatorFunction, self.func)
            return core_schema.no_info_after_validator_function(func, schema=schema)

    @classmethod
    def _from_decorator(cls, decorator: _decorators.Decorator[_decorators.FieldValidatorDecoratorInfo]) -> Self:
        return cls(func=decorator.func)