この出力は何になるでしょう?

memory_sample.py

# coding: utf-8

class Entity(object):
    def __init__(self, entity_type, entity_id):
        self.entity_type = entity_type
        self.entity_id = entity_id


class Reward(object):
    def __init__(self, entity_type, entity_id, number):
        self.entity_type = entity_type
        self.entity_id = entity_id
        self.number = number

    @property
    def entity(self):
        return get_entity(self.entity_type, self.entity_id)


e = {
    1: {1: Entity(1, 1), 2: Entity(1, 2)},
    2: {1: Entity(2, 1), 2: Entity(2, 2)}
}


def get_entity(entity_type, entity_id):
    return e[entity_type][entity_id]


def main():
    rewards = [Reward(1, 1, 1), Reward(2, 1, 1), Reward(2, 1, 2), Reward(1, 1, 3)]
    entities = []
    for r in rewards:
        entity = r.entity
        entity.number = r.number
        print 'reward type = {}, id = {}, number = {}'.format(r.entity_type, r.entity_id, r.number)
        entities.append(entity)

    for e in entities:
        print 'entity type = {}, id = {}, number = {}'.format(e.entity_type, e.entity_id, e.number)

'''
from django.db import models
from django.core.cache import cache


class CacheHelper(object):
    @classmethod
    def get(cls, pk):
        data = cache.get('{}:pk:{}'.format(cls.__module__, cls.__name__, pk), None)
        if not data:
            data = cls.objects.get(pk=pk)
            cache.set('{}:pk:{}'.format(cls.__module__, cls.__name__, pk), data)
        return data

    @classmethod
    def all(cls):
        data = cache.get('{}:all'.format(cls.__module__, cls.__name__), [])
        if not data:
            data = list(cls.objects.all())
            cache.set('{}:all'.format(cls.__module__, cls.__name__), data)
        return data


---------------
| id | name   |
---------------
| 1  | card1  |
---------------
| 2  | card2  |
---------------

class Card(models.Model, CacheHelper):
    name = models.CharFiled()


---------------
| id | name   |
---------------
| 1  | item1  |
---------------
| 2  | item2  |
---------------


class Item(models.Model, CacheHelper):
    name = models.CharField()


def get_entity(entity_type, entity_id):
    if entity_type == 1:
        model = Card
    elif entity_type == 2:
        model = Item
    return model.get(entity_id)


class Entity(models.Model):
    entity_type = models.IntegerField()
    entity_id = models.IntegerField()
    
    class Meta:
        abstract = True

    @property
    def entity(self):
        return get_entity(self.entity_type, self.entity_id)


-----------------------------------------
| id | entity_type | entity_id | number |
-----------------------------------------
| 1  |      1      |     1     |    1   |
-----------------------------------------
| 2  |      1      |     2     |    2   |
-----------------------------------------
| 3  |      2      |     2     |    5   |
-----------------------------------------
| 4  |      2      |     1     |    2   |
-----------------------------------------
| 5  |      1      |     1     |    3   |
----------------------------------------
| 6  |      2      |     2     |    1   |
-----------------------------------------

class Reward(Entity, CacheHelper):
    number = models.IntegerField()


def main():
    entities = []
    for reward in Reward.all():
        print 'reward type = {}, id = {}, number = {}'.format(reward.entity_type, reward.entity_id, reward.number)
        entity = reward.entity
        entity.number = reward.number
        entities.append(entity)

    for entity in entities:
        print 'entity name = {}, number = {}'.format(entity.name, entity.entity_id, entity.number)

'''


if __name__ == '__main__':
     main()