class Vehicle(object):
    """Document String: Define a Vehicle class"""
 
    def __init__(self, brand, year):
        self._brand = brand;
        self._year = year;
 
    @property
    def brand(self):
        return self._brand
 
    @brand.setter
    def brand(self, b):
        self._brand = b;
 
    @brand.deleter
    def brand(self):
        del self._brand
 
    @property
    def year(self):
        return self._year
 
    @year.setter
    def year(self, y):
        self._year = y
 
    @year.deleter
    def year(self):
        del self._year
 
    def __str__(self):
        return self._brand+' '+str(self._year)
 
    def __getattr__(self, attr): # intercept that inexistent attribute
        return '~'
		

from Vehicle import Vehicle;
 
class Car(Vehicle):
    """Define class Car, which is inherit from class Vehicle"""
    def __init__(self, brand, year, model):
        """Construct"""
        print("Create Car Object ...")
        super(Car, self).__init__(brand, year);
        #Vehicle.__init__(self, brand, year);
        self.__model = model;

    @property
    def model(self):
        return self.__model
 
    @model.setter
    def model(self, value):
        self.__model = value
 
    @model.deleter
    def model(self):
        del self.__model
 
    # override __str__ in Vehicle
    def __str__(self):
        #return super(Car, self).__str__() + " " + self.model
        return Vehicle.__str__(self) + " " + self.model
 
def main():
    v = Vehicle("Buick", 1998)
    print(v)
 
    c = Car("Lincoln", 1998, "Continental");
    print(c)
 
    print(issubclass(Car, Vehicle)) # True
    print(isinstance(c, Car)) # True
 
if __name__ == '__main__':
    main();
		

class Vehicle(object):
    """Abstract base class Vehicle"""
 
    def __init__(self, brand, year):
        if self.__class__ == Vehicle:
            raise NotImplementedError('Cannot create Vehicle instance ...')
 
        self._brand = brand;
        self._year = year;
 
    @property
    def brand(self):
        return self._brand
 
    @brand.setter
    def brand(self, b):
        self._brand = b;
 
    @brand.deleter
    def brand(self):
        del self._brand
 
    @property
    def year(self):
        return self._year
 
    @year.setter
    def year(self, y):
        self._year = y
 
    @year.deleter
    def year(self):
        del self._year
 
    def __str__(self):
        return self._brand+' '+str(self._year)
 
    def __getattr__(self, attr): # intercept that inexistent attribute
        return '~'
		

from Vehicle import Vehicle;
 
class Car(Vehicle):
    """Define class Car, which is inherit from class Vehicle"""
    def __init__(self, brand, year, model):
        """Construct"""
        print("Create Car Object ...") 
        super(Car, self).__init__(brand, year);
	#Vehicle.__init__(self, brand, year);
        self.__model = model;
 
    @property
    def model(self):
        return self.__model
 
    @model.setter
    def model(self, value):
        self.__model = value
 
    @model.deleter
    def model(self):
        del self.__model
 
    # override __str__ in Vehicle
    def __str__(self):
        #return super(Car, self).__str__() + " " + self.model
        return Vehicle.__str__(self) + " " + self.model
 
def main():
    try:
        v = Vehicle("Buick", 1998) # Vehicle is an abstract class, can not be used to create instance
    except Exception as err:
        print(err)
 
    c = Car("Lincoln", 1998, "Continental");
    print(c)
 
if __name__ == '__main__':
    main();