(🐞) Enum with multiple values (tuple) can't be round tripped through json #10629
Description
Initial Checks
- I confirm that I'm using Pydantic V2
Description
pydantic_core._pydantic_core.ValidationError: 1 validation error for RootModel[A]
a
Input should be (1, 2) [type=enum, input_value=[1, 2], input_type=list]
For further information visit https://errors.pydantic.dev/2.9/v/enum
Enums support functionality where a tuple ("multiple values") is assigned to the member
here, we see that pydantic does not support serialising and parsing of this type of Enum value
Workaround
add a core schema to the class:
@classmethod
def __get_pydantic_core_schema__(cls, source_type, handler):
return core_schema.no_info_before_validator_function(
lambda data: data if isinstance(data, cls) else tuple(data), handler(source_type)
)Example Code
from enum import Enum
from pydantic import RootModel
class A(Enum):
a = 1, 2
serialised = RootModel[A](A.a).model_dump_json()
parsed = RootModel[A].model_validate_json(serialised)Python, Pydantic & OS Version
pydantic version: 2.9.2
pydantic-core version: 2.23.4
pydantic-core build: profile=release pgo=false
install path: C:\Users\AMONGUS\projects\test\.venv\Lib\site-packages\pydantic
python version: 3.12.2 (tags/v3.12.2:6abddd9, Feb 6 2024, 21:26:36) [MSC v.1937 64 bit (AMD64)]
platform: Windows-10-10.0.19045-SP0
related packages: typing_extensions-4.12.2
commit: unknown