jsonable_encoder does not take the Config into account for Enums

[ebreton]

Describe the bug

When calling jsonable_encoder on a pydantic object that makes use of an Enum for a field, the JSON response contains the Enum.field.value, whereas the default behavior should be to use Enum.field.name (as per the Config.use_enum_values which is False by default)

in the code, file encoders.py, around line 26:

def jsonable_encoder
...
    if isinstance(obj, Enum):
        return obj.value

To Reproduce
Steps to reproduce the behavior:

1. Create a file with

from enum import Enum
from pydantic import BaseModel

class AuditType(Enum):
    rank = "RankValue"
    count = "CountValue"

class AuditBase(BaseModel):
    type: AuditType = None

2. Add a test which calls jsonable_encoder on an instance

from fastapi.encoders import jsonable_encoder
obj_in = AuditBase(type=AuditType.count)
print(jsonable_encoder(obj_in))

4. See error, i.e {'type': 'CountValue'} instead of {'type': 'count'}

Expected behavior

The expected behavior should be to check the value of the Config.use_enum_values and return the name or the value appropriately

Environment:

• FastAPI Version 0.18.0
• Python version 3.7.2

[tiangolo]

Thanks for the report. I'll check it.

[tiangolo]

I'm delaying this until pydantic/pydantic#520 is resolved.

It will change how responses are encoded from Pydantic models in a much cleaner way. And it will solve several issues at the same time (most probably including this).

[tiangolo]

Pydantic has a recent/new ORM mode.

I just finished a deep integration of it into FastAPI. It is released in version 0.30.0 🎉

Now, if you use a response_model, Pydantic will take whatever is returned by your path operation function and use it directly. Without being passed through jsonable_encoder.

If you use ORM object (SQLAlchemy, Peewee, etc) you should use Pydantic's orm_mode = True to tell Pydantic to extract the data from the ORM objects. The new docs are here: https://fastapi.tiangolo.com/tutorial/sql-databases/

Also, in case I'm misunderstanding the question, specific to the configs set in Pydantic models, I'm pretty sure the jsonable_encoder was updated at some point to use the configs from the model, maybe your specific issue was solved by that change in a previous version?

[tiangolo]

I assume this was solved in recent versions, so I'll close this issue.

But feel free to add more comments or create new issues.

[github-actions]

Assuming the original need was handled, this will be automatically closed now. But feel free to add more comments or create new issues or PRs.