models/price.py

from pydantic import BaseModel, validator


class PricePayload(BaseModel):
    symbol: str
    count_back: int = 150
    source: str = "database"

    @validator("source")
    def valid_source(cls, v):
        if v not in ["database", "vnstock"]:
            raise ValueError('source must be database or vnstock')
        return v