datavalidator.py

from datetime import datetime
from uuid import UUID, uuid4
from typing import Literal, Optional, Union
from pydantic import BaseModel, Field, ValidationError, validator, constr, confloat


class HouseDataValidation(BaseModel):

    id: Union[int, UUID] = Field(default_factory=uuid4)
    kind: Literal["villa", "apartment", "townhouse"]
    sales_date: datetime
    downpayment: Optional[confloat(ge=0)] = 0.0
    price: confloat(gt=1e3, lt=1e10)
    comment: Optional[constr(max_length=300)] = None

    @validator("sales_date")
    def sales_date_validation(cls, v):
        # sales date cannot be none or more than 31 days old
        if v is None:
            raise ValueError("sales date cannot be None")

        today = datetime.now()
        sales_days_old = (today - v).days
        if sales_days_old > 31:
            raise ValueError(
                f"sales is {sales_days_old} days old. "
                "sales date cannot be more than 31 days old"
            )
        return v

    @validator("price")
    def sales_validation(cls, v, values):
        # price cannot lower than downpayment
        if values.get("downpayment") and v < values["downpayment"]:

            raise ValueError(
                f"sales price {v} cannot be lower "
                f"than downpayment: {values['downpayment']}."
            )

        return v