py-enum-examples.py

from dataclasses import dataclass
from enum import StrEnum, auto, Enum
from pydantic import BaseModel, ConfigDict

### StrEnum ######################################

class Status1(StrEnum):
    OK = auto()  # with auto value
    ERR = auto()

class StatSchema1(BaseModel):
    model_config = ConfigDict(from_attributes=True)
    name: str
    status: Status1

@dataclass
class Entity1:
    name: str
    status: Status1

e1 = Entity1(name='test', status=Status1.OK)
print(StatSchema1.model_validate(e1).model_dump(mode='json'))
# {'name': 'test', 'status': 'ok'} <- good

### str + Enum ######################################

class Status2(str, Enum):
    OK = auto()
    ERR = auto()

class StatSchema2(BaseModel):
    model_config = ConfigDict(from_attributes=True)
    name: str
    status: Status2

@dataclass
class Entity2:
    name: str
    status: Status2

e2 = Entity2(name='test', status=Status2.OK)
print(StatSchema2.model_validate(e2).model_dump(mode='json'))
# {'name': 'test', 'status': '1'} <- wrong value with auto()!

### Enum ####################################
class Status3(Enum): 
    OK = 'ok'   # no auto()
    ERR = 'err'

class StatSchema3(BaseModel):
    model_config = ConfigDict(from_attributes=True)
    name: str
    status: Status3
    
@dataclass
class Entity3:
    name: str
    status: Status3

e3 = Entity3(name='test', status=Status3.OK)
print(StatSchema3.model_validate(e3).model_dump(mode='json'))
# {'name': 'test', 'status': 'ok'}