classes.py

class Cars:
    # Class attribute
    fuel = "Petrol"

    # Instance attributes
    def __init__(self, brand: str, model: str, year: int, color: str):
        self.brand = brand
        self.model = model
        self.year = year
        self.color = color

    # class method
    @classmethod
    def car_fuel(cls, fuel: str):
        cls.fuel = fuel

    # instance method
    def car_details(self):
        return f"Brand: {self.brand} Model:{self.model} Year: {self.year} Fuel: {self.fuel}, Color: {self.color}"

    # static method
    @staticmethod
    def car_color(color: str):
        if color == "white":
            return "white"
        if color != "white":
            return "not white"