How to concatenate multiple fields into one in a Response Schema ?

[simonpanay]

Hi,

Considering the folowing model :

class Epoch(models.Model):
    ...
    band_code = models.CharField(max_length=1)
    instrument_code = models.CharField(max_length=1)
    orientation_code = models.CharField(max_length=1)
    ...

I would like to generate a schema like this one

class EpochSchema(Schema):
    code: str

with code being band_code + instrument_code + orientation_code

I tried to use a resolve_code() method that concatenates all those codes to make one. But the only way it is working is to integrate band_code, instrument_code, etc.. into my EpochSchema

Is there a possibility to build my code field into EpochSchema without including all the original fields ?

[simonpanay]

Finally found a solution here : https://docs.pydantic.dev/latest/concepts/fields/#exclude
The idea is to exclude those fields when "exporting" the schema

So in my example, the solution is :

class EpochSchema(Schema):
    code: str
    band_code: str = Field(exclude=True)
    instrument_code: str = Field(exclude=True)
    orientation_code: str = Field(exclude=True)

    @staticmethod
    def resolve_code(obj):
        return f"{obj.band_code}{obj.instrument_code}{obj.orientation_code}"

Sorry for the unnecessary noise