Student, a Subclass of a Subclass, and the Rabbit Class Variable

How can the single line `Person.__init__(self, name, age)` set up the entire person part of a student, and what kind of variable hands every rabbit a unique ID?

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Short drills on what this video just taught. Write the code, run the checks, and reveal the answer only if you are stuck.

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Write Student, whose parent is Person. Creating one takes three things — a name, an age, and a major that is None when it is not supplied — so Student cannot reuse the two-parameter initializer it inherits and has to write its own. Build the whole person part of a student with a single call to the parent's initializer, made by class name, then add the one data attribute a student has that a person does not: major.

Then create a student named 'alice', aged 20, majoring in "CS", and assign it to student.
Given code — runs before yours
```
class Animal(object):
    """ An animal with an age and a name """

    def __init__(self, age):
        self.age = age
        self.name = None

    def get_age(self):
        return self.age

    def get_name(self):
        return self.name

    def set_age(self, newage):
        self.age = newage

    def set_name(self, newname=""):
        self.name = newname

    def __str__(self):
        return "animal:" + str(self.name) + ":" + str(self.age)

class Person(Animal):
    """ An animal with a name from the start and a list of friends """

    def __init__(self, name, age):
        Animal.__init__(self, age)
        self.set_name(name)
        self.friends = []

    def get_friends(self):
        return self.friends

    def add_friend(self, fname):
        if fname not in self.friends:
            self.friends.append(fname)

    def speak(self):
        print("hello")

    def __str__(self):
        return "person:" + str(self.name) + ":" + str(self.age)
```
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# A student is a person, plus one thing of its own. class Student(Person): ... # your code here — the initializer student = ... # your code here
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⌘/Ctrl + Enter runs
Student is a subclass of Person that writes its own __init__
is a Student carrying the name and age it was built with
stores the major as a data attribute of its own
the person part came from one call to the parent
the major falls back to its default when it is left out

←Previous Overriding __init__: Person Calls Animal.__init__ By Name Next __add__ and __eq__ on Rabbits: Operator Overloading With Shared IDs →

class Animal(object): """ An animal with an age and a name """ def __init__(self, age): self.age = age self.name = None def get_age(self): return self.age def get_name(self): return self.name def set_age(self, newage): self.age = newage def set_name(self, newname=""): self.name = newname def __str__(self): return "animal:" + str(self.name) + ":" + str(self.age) class Person(Animal): """ An animal with a name from the start and a list of friends """ def __init__(self, name, age): Animal.__init__(self, age) self.set_name(name) self.friends = [] def get_friends(self): return self.friends def add_friend(self, fname): if fname not in self.friends: self.friends.append(fname) def speak(self): print("hello") def __str__(self): return "person:" + str(self.name) + ":" + str(self.age)