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# -*- coding: utf-8 -*-
"""
42. Serialization
``django.core.serializers`` provides interfaces to converting Django
``QuerySet`` objects to and from "flat" data (i.e. strings).
"""
from __future__ import unicode_literals
from decimal import Decimal
from django.db import models
from django.utils import six
from django.utils.encoding import python_2_unicode_compatible
@python_2_unicode_compatible
class Category(models.Model):
name = models.CharField(max_length=20)
class Meta:
ordering = ('name',)
def __str__(self):
return self.name
@python_2_unicode_compatible
class Author(models.Model):
name = models.CharField(max_length=20)
class Meta:
ordering = ('name',)
def __str__(self):
return self.name
@python_2_unicode_compatible
class Article(models.Model):
author = models.ForeignKey(Author)
headline = models.CharField(max_length=50)
pub_date = models.DateTimeField()
categories = models.ManyToManyField(Category)
class Meta:
ordering = ('pub_date',)
def __str__(self):
return self.headline
@python_2_unicode_compatible
class AuthorProfile(models.Model):
author = models.OneToOneField(Author, primary_key=True)
date_of_birth = models.DateField()
def __str__(self):
return "Profile of %s" % self.author
@python_2_unicode_compatible
class Actor(models.Model):
name = models.CharField(max_length=20, primary_key=True)
class Meta:
ordering = ('name',)
def __str__(self):
return self.name
@python_2_unicode_compatible
class Movie(models.Model):
actor = models.ForeignKey(Actor)
title = models.CharField(max_length=50)
price = models.DecimalField(max_digits=6, decimal_places=2, default=Decimal('0.00'))
class Meta:
ordering = ('title',)
def __str__(self):
return self.title
class Score(models.Model):
score = models.FloatField()
@python_2_unicode_compatible
class Team(object):
def __init__(self, title):
self.title = title
def __str__(self):
raise NotImplementedError("Not so simple")
def to_string(self):
return "%s" % self.title
class TeamField(six.with_metaclass(models.SubfieldBase, models.CharField)):
def __init__(self):
super(TeamField, self).__init__(max_length=100)
def get_db_prep_save(self, value, connection):
return six.text_type(value.title)
def to_python(self, value):
if isinstance(value, Team):
return value
return Team(value)
def value_to_string(self, obj):
return self._get_val_from_obj(obj).to_string()
@python_2_unicode_compatible
class Player(models.Model):
name = models.CharField(max_length=50)
rank = models.IntegerField()
team = TeamField()
def __str__(self):
return '%s (%d) playing for %s' % (self.name, self.rank, self.team.to_string())
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