Arguments to __init__ when using a subclass and super

Question

I'm spending a nice Saturday looking a bit deeper into Python objects, and had a simple question that isn't mindblowing but kinda curious.

Say I have a base class and a subclass as follows :

class Person:

    def __init__(self, first, last):
        self.firstname = first
        self.lastname = last

    def __str__(self):
        return self.firstname + " " + self.lastname

class Employee(Person):

    def __init__(self, first, last, staffnum):
        super().__init__(first, last)
        self.staffnumber = staffnum


x = Person("Marge", "Simpson")
y = Employee("Homer", "Simpson", "1007")

I'm looking at the Employee class.

Given:
we are using super() and it has arguments in it,
why in python does the __init__ still require us to type first, last ?
Shouldn't this be inferred from our use of super? Seems like extra repetitive typing. What's the reasoning for the author having to do this?

Answer 1

The reason is so you can further customize subclasses. In your example, when you still want to input first and last it is more of a hassle because you have to type it twice, like this:

class Employee(Person):
    def __init__(self, first, last):
        super().__init__(first, last)

emp1 = Employee("Bob", "Jones")

However, you might want to autofill some of those values. In this example maybe a FamilyMember class where the last name is common.

class FamilyMember(Person):
    def __init__(self, first):
        super().__init__(first, last="Erikson")

fm1 = FamilyMember("Paul")

In this case you would only need to input the first variable for a FamilyMember and the last variable would be automatically filled in.