#!/usr/bin/env python
import struct

class Formatters(object):
    @staticmethod
    def string(val): return '{}s'.format(len(val)), bytes(val, 'utf-8')
    @staticmethod
    def uint64(val): return 'Q', val


class Person(object):
    __slots__ = ['vorname', 'nachname']
    _wandler = {
        'vorname': Formatters.string,
        'nachname': Formatters.string
    }
    
    def __init__(self, vorname, nachname):
        self.vorname = vorname
        self.nachname = nachname

    def __repr__(self):
        return '{} {}'.format(self.vorname, self.nachname)

    def serialize(self):
        formatstr = list()
        arguments = list()
        for i in self.__slots__:
            w = self._wandler[i](getattr(self, i, None))
            formatstr.append(w[0])
            arguments.append(w[1])
        return struct.pack(''.join(formatstr), *arguments)


class Student(Person):
    # __slots__ wird NICHT vererbt!
    __slots__ = Person.__slots__ + ['graduation']
    
    def __init__(self, vorname, nachname, graduation):
        super().__init__(vorname, nachname)
        self._wandler.update({'graduation': Formatters.uint64})
        self.graduation = int(graduation)
    
    def __repr__(self):
        return '{} {}'.format(self.vorname, self.nachname)


if __name__ == '__main__':
    p = Person('Sheeva', 'Plug')
    print(p)
    print(p.serialize())
        
    p = Student('Sheeva', 'Plug', 1991)
    print(p)
    print(p.serialize())