import abc
from abc import ABCMeta
 
 
class Person(object, metaclass=ABCMeta):
    def __init__(self, first, last, age):
        self.firstname = first
        self.lastname = last
        self.age = age
 
    @abc.abstractmethod
    def change_info(self):
        pass
 
 
class Employee(Person):
    def __init__(self, first, last, age, staffnum):
        super(Employee, self).__init__(first, last, age)
        self.staffnumber = staffnum
 
    def change_info(self, firstname, lastname, age, staffnum):
        self.firstname = firstname
        self.lastname = lastname
        self.age = age
        self.staffnum = staffnum
 
 
y = Employee("Homer", "Simpson", 28, "1007")
y.change_info("Harry", "Potter", 20, "322")
print(y.firstname)

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