Python inheritance returns attribute error

Question

Just starting out Python, i\'m a fan of Derek Banas and have been following a tutorial and I\'m stuck with a bit of code.

class Dog(Animal):
    __owner = \"         


        

Answer 1

The child class itself doesn't have the attribute, use this instead.

return super(Dog, self).toString() + "His owner is {}".format(self.__owner)

Answer 2

Change your function code

from

def toString(self):
        return "{} is {} cm tall and {} kilograms and say {} and the owner is {}".format(
        self.__name,
        self.__height,
        self.__weight,
        self.__sound,
        self.__owner)

to

def toString(self):
        return "{} is {} cm tall and {} kilograms and say {} and the owner is {}".format(
        self.get_name(),
        self.get_height(),
        self.get_weight(),
        self.get_sound(),
        self.get_owner())

Answer 3

Your Animal class is using Name Mangling. From documentation -

Since there is a valid use-case for class-private members (namely to avoid name clashes of names with names defined by subclasses), there is limited support for such a mechanism, called name mangling. Any identifier of the form __spam (at least two leading underscores, at most one trailing underscore) is textually replaced with _classname__spam, where classname is the current class name with leading underscore(s) stripped.

(Emphasis mine)

Hence , after your Animal class got defined any name such as __name would have changed to _Animal__name , etc. You would also need to access them alike that in your Dog class.

But I don't think you actually need to use Name Mangling , you should avoid using the two leading underscores, if you didn't mean for Name Mangling to happen.