How to rename keys in response from database by pydantic schema - FastAPI

Question

I have a model from my database in models.py:

class Something(Base):
    __tablename__ = "something"

    DATE = Column(Date, primary_key=True, index=True )  
    a = Column(String, primary_key=True, index=True)
    b = Column(Integer, primary_key=True, index=True)
    c = Column(Float, index=True) 
    d = Column(Integer, index=True)
    e = Column(Integer, index=True)
    f = Column(Float, index=True)
    g = Column(Float, index=True)  
    h = Column(Integer, index=True)  

and a pydantic model in schema.py:

class Something(BaseModel):
    DATE: date
    a: str
    b: int
    c: float = None
    d: int = None
    e: int = None
    f: float = None
    g: float = None
    h: int = None

    class Config:
        orm_mode = True

I get data from the database which go through the ORM and in app.get() I declare the response model equal to List[schema.Something], but I want to change the names from the database a, b, c, d to more beautiful names. Is there a solution like mapping names in NestJS?

Answer 1

Try to use aliases, this is what option allow_population_by_field_name allows to do, for example:

class Person(BaseModel):
    first_name: str = Field(..., alias='first')
    last_name: str = Field(..., alias='second')

    class Config:
        allow_population_by_field_name = True


p = Person(**{'first': 'John', 'second': 'White'})
print(p.__dict__)

# {'first_name': 'John', 'last_name': 'White'}