Derived class' class variable demo in Python

class Person(object):
    count = 0

    def __init__(self, name, age):
        klass = globals()[self.__class__.__name__]
        self.name = name
        self.age = age
        klass.count += 1

    def __del__(self):
        klass = globals()[self.__class__.__name__]
        klass.count -= 1

    @classmethod
    def get_count(cls):
        return cls.count

class Student(Person):
    def __init__(self, name, age):
        klass = globals()[self.__class__.__name__]
        super(klass, self).__init__(name, age)
        for base in self.__class__.__bases__:
            parent = globals()[base.__name__]
            parent.count += 1

    def __del__(self):
        klass = globals()[self.__class__.__name__]
        super(klass, self).__del__()
        for base in self.__class__.__bases__:
            parent = globals()[base.__name__]
            parent.count -= 1

if __name__ == '__main__':
    a = Student('Michael', 35)
    b = Person('Gladys', 52)
    c = Student('Susan', 26)

    print 'person:', Person.get_count()
    print 'student:', Student.get_count()

    del c
    print 'person:', Person.get_count()
    print 'student:', Student.get_count()