Python django.core.serializers.deserialize() Examples

def handle(self, *args, **options):
        """Reloads a dumped access list and removes the totals from the historic views.

        :param args: None
        :param options: None
        :return: None
        """

        file_path = os.path.join(settings.BASE_DIR,
                                 'files',
                                 'data_backup',
                                 options.get('file'),
                                 'article_accesses.json')

        with open(file_path, encoding="utf-8") as f:
            data = f.read()

        for obj in serializers.deserialize("json", data):
            obj.save()

            if obj.object.type == 'view':
                obj.object.article.historicarticleaccess.remove_one_view()
            elif obj.object.type == 'download':
                obj.object.article.historicarticleaccess.remove_one_download() 

def test_naive_datetime_with_microsecond(self):
        dt = datetime.datetime(2011, 9, 1, 13, 20, 30, 405060)

        data = serializers.serialize('python', [Event(dt=dt)])
        self.assert_python_contains_datetime(data, dt)
        obj = next(serializers.deserialize('python', data)).object
        self.assertEqual(obj.dt, dt)

        data = serializers.serialize('json', [Event(dt=dt)])
        self.assert_json_contains_datetime(data, "2011-09-01T13:20:30.405")
        obj = next(serializers.deserialize('json', data)).object
        self.assertEqual(obj.dt, dt.replace(microsecond=405000))

        data = serializers.serialize('xml', [Event(dt=dt)])
        self.assert_xml_contains_datetime(data, "2011-09-01T13:20:30.405060")
        obj = next(serializers.deserialize('xml', data)).object
        self.assertEqual(obj.dt, dt)

        if not isinstance(serializers.get_serializer('yaml'), serializers.BadSerializer):
            data = serializers.serialize('yaml', [Event(dt=dt)], default_flow_style=None)
            self.assert_yaml_contains_datetime(data, "2011-09-01 13:20:30.405060")
            obj = next(serializers.deserialize('yaml', data)).object
            self.assertEqual(obj.dt, dt) 

def setUp(self):
        self.image = Image.objects.create(
            title="Test image",
            file=get_test_image_file(),
        )

        # Create an image with a missing file, by deserializing fom a python object
        # (which bypasses FileField's attempt to read the file)
        self.bad_image = list(serializers.deserialize('python', [{
            'fields': {
                'title': 'missing image',
                'height': 100,
                'file': 'original_images/missing-image.jpg',
                'width': 100,
            },
            'model': 'wagtailimages.image'
        }]))[0].object
        self.bad_image.save() 

def setUp(self):
        self.engine = engines['jinja2']

        self.image = Image.objects.create(
            title="Test image",
            file=get_test_image_file(),
        )

        # Create an image with a missing file, by deserializing fom a python object
        # (which bypasses FileField's attempt to read the file)
        self.bad_image = list(serializers.deserialize('python', [{
            'fields': {
                'title': 'missing image',
                'height': 100,
                'file': 'original_images/missing-image.jpg',
                'width': 100,
            },
            'model': 'wagtailimages.image'
        }]))[0].object
        self.bad_image.save() 

def test_naive_datetime(self):
        dt = datetime.datetime(2011, 9, 1, 13, 20, 30)

        data = serializers.serialize('python', [Event(dt=dt)])
        self.assert_python_contains_datetime(data, dt)
        obj = next(serializers.deserialize('python', data)).object
        self.assertEqual(obj.dt, dt)

        data = serializers.serialize('json', [Event(dt=dt)])
        self.assert_json_contains_datetime(data, "2011-09-01T13:20:30")
        obj = next(serializers.deserialize('json', data)).object
        self.assertEqual(obj.dt, dt)

        data = serializers.serialize('xml', [Event(dt=dt)])
        self.assert_xml_contains_datetime(data, "2011-09-01T13:20:30")
        obj = next(serializers.deserialize('xml', data)).object
        self.assertEqual(obj.dt, dt)

        if not isinstance(serializers.get_serializer('yaml'), serializers.BadSerializer):
            data = serializers.serialize('yaml', [Event(dt=dt)])
            self.assert_yaml_contains_datetime(data, "2011-09-01 13:20:30")
            obj = next(serializers.deserialize('yaml', data)).object
            self.assertEqual(obj.dt, dt) 

def test_naive_datetime_with_microsecond(self):
        dt = datetime.datetime(2011, 9, 1, 13, 20, 30, 405060)

        data = serializers.serialize('python', [Event(dt=dt)])
        self.assert_python_contains_datetime(data, dt)
        obj = next(serializers.deserialize('python', data)).object
        self.assertEqual(obj.dt, dt)

        data = serializers.serialize('json', [Event(dt=dt)])
        self.assert_json_contains_datetime(data, "2011-09-01T13:20:30.405")
        obj = next(serializers.deserialize('json', data)).object
        self.assertEqual(obj.dt, dt.replace(microsecond=405000))

        data = serializers.serialize('xml', [Event(dt=dt)])
        self.assert_xml_contains_datetime(data, "2011-09-01T13:20:30.405060")
        obj = next(serializers.deserialize('xml', data)).object
        self.assertEqual(obj.dt, dt)

        if not isinstance(serializers.get_serializer('yaml'), serializers.BadSerializer):
            data = serializers.serialize('yaml', [Event(dt=dt)])
            self.assert_yaml_contains_datetime(data, "2011-09-01 13:20:30.405060")
            obj = next(serializers.deserialize('yaml', data)).object
            self.assertEqual(obj.dt, dt) 

def test_aware_datetime_with_microsecond(self):
        dt = datetime.datetime(2011, 9, 1, 17, 20, 30, 405060, tzinfo=ICT)

        data = serializers.serialize('python', [Event(dt=dt)])
        self.assert_python_contains_datetime(data, dt)
        obj = next(serializers.deserialize('python', data)).object
        self.assertEqual(obj.dt, dt)

        data = serializers.serialize('json', [Event(dt=dt)])
        self.assert_json_contains_datetime(data, "2011-09-01T17:20:30.405+07:00")
        obj = next(serializers.deserialize('json', data)).object
        self.assertEqual(obj.dt, dt.replace(microsecond=405000))

        data = serializers.serialize('xml', [Event(dt=dt)])
        self.assert_xml_contains_datetime(data, "2011-09-01T17:20:30.405060+07:00")
        obj = next(serializers.deserialize('xml', data)).object
        self.assertEqual(obj.dt, dt)

        if not isinstance(serializers.get_serializer('yaml'), serializers.BadSerializer):
            data = serializers.serialize('yaml', [Event(dt=dt)])
            self.assert_yaml_contains_datetime(data, "2011-09-01 17:20:30.405060+07:00")
            obj = next(serializers.deserialize('yaml', data)).object
            self.assertEqual(obj.dt.replace(tzinfo=UTC), dt) 

def test_aware_datetime_in_utc(self):
        dt = datetime.datetime(2011, 9, 1, 10, 20, 30, tzinfo=UTC)

        data = serializers.serialize('python', [Event(dt=dt)])
        self.assert_python_contains_datetime(data, dt)
        obj = next(serializers.deserialize('python', data)).object
        self.assertEqual(obj.dt, dt)

        data = serializers.serialize('json', [Event(dt=dt)])
        self.assert_json_contains_datetime(data, "2011-09-01T10:20:30Z")
        obj = next(serializers.deserialize('json', data)).object
        self.assertEqual(obj.dt, dt)

        data = serializers.serialize('xml', [Event(dt=dt)])
        self.assert_xml_contains_datetime(data, "2011-09-01T10:20:30+00:00")
        obj = next(serializers.deserialize('xml', data)).object
        self.assertEqual(obj.dt, dt)

        if not isinstance(serializers.get_serializer('yaml'), serializers.BadSerializer):
            data = serializers.serialize('yaml', [Event(dt=dt)])
            self.assert_yaml_contains_datetime(data, "2011-09-01 10:20:30+00:00")
            obj = next(serializers.deserialize('yaml', data)).object
            self.assertEqual(obj.dt.replace(tzinfo=UTC), dt) 

def test_aware_datetime_in_local_timezone(self):
        dt = datetime.datetime(2011, 9, 1, 13, 20, 30, tzinfo=EAT)

        data = serializers.serialize('python', [Event(dt=dt)])
        self.assert_python_contains_datetime(data, dt)
        obj = next(serializers.deserialize('python', data)).object
        self.assertEqual(obj.dt, dt)

        data = serializers.serialize('json', [Event(dt=dt)])
        self.assert_json_contains_datetime(data, "2011-09-01T13:20:30+03:00")
        obj = next(serializers.deserialize('json', data)).object
        self.assertEqual(obj.dt, dt)

        data = serializers.serialize('xml', [Event(dt=dt)])
        self.assert_xml_contains_datetime(data, "2011-09-01T13:20:30+03:00")
        obj = next(serializers.deserialize('xml', data)).object
        self.assertEqual(obj.dt, dt)

        if not isinstance(serializers.get_serializer('yaml'), serializers.BadSerializer):
            data = serializers.serialize('yaml', [Event(dt=dt)])
            self.assert_yaml_contains_datetime(data, "2011-09-01 13:20:30+03:00")
            obj = next(serializers.deserialize('yaml', data)).object
            self.assertEqual(obj.dt.replace(tzinfo=UTC), dt) 

def test_naive_datetime_with_microsecond(self):
        dt = datetime.datetime(2011, 9, 1, 13, 20, 30, 405060)

        data = serializers.serialize('python', [Event(dt=dt)])
        self.assert_python_contains_datetime(data, dt)
        obj = next(serializers.deserialize('python', data)).object
        self.assertEqual(obj.dt, dt)

        data = serializers.serialize('json', [Event(dt=dt)])
        self.assert_json_contains_datetime(data, "2011-09-01T13:20:30.405")
        obj = next(serializers.deserialize('json', data)).object
        self.assertEqual(obj.dt, dt.replace(microsecond=405000))

        data = serializers.serialize('xml', [Event(dt=dt)])
        self.assert_xml_contains_datetime(data, "2011-09-01T13:20:30.405060")
        obj = next(serializers.deserialize('xml', data)).object
        self.assertEqual(obj.dt, dt)

        if not isinstance(serializers.get_serializer('yaml'), serializers.BadSerializer):
            data = serializers.serialize('yaml', [Event(dt=dt)])
            self.assert_yaml_contains_datetime(data, "2011-09-01 13:20:30.405060")
            obj = next(serializers.deserialize('yaml', data)).object
            self.assertEqual(obj.dt, dt) 

def test_aware_datetime_with_microsecond(self):
        dt = datetime.datetime(2011, 9, 1, 17, 20, 30, 405060, tzinfo=ICT)

        data = serializers.serialize('python', [Event(dt=dt)])
        self.assert_python_contains_datetime(data, dt)
        obj = next(serializers.deserialize('python', data)).object
        self.assertEqual(obj.dt, dt)

        data = serializers.serialize('json', [Event(dt=dt)])
        self.assert_json_contains_datetime(data, "2011-09-01T17:20:30.405+07:00")
        obj = next(serializers.deserialize('json', data)).object
        self.assertEqual(obj.dt, dt.replace(microsecond=405000))

        data = serializers.serialize('xml', [Event(dt=dt)])
        self.assert_xml_contains_datetime(data, "2011-09-01T17:20:30.405060+07:00")
        obj = next(serializers.deserialize('xml', data)).object
        self.assertEqual(obj.dt, dt)

        if not isinstance(serializers.get_serializer('yaml'), serializers.BadSerializer):
            data = serializers.serialize('yaml', [Event(dt=dt)])
            self.assert_yaml_contains_datetime(data, "2011-09-01 17:20:30.405060+07:00")
            obj = next(serializers.deserialize('yaml', data)).object
            self.assertEqual(obj.dt.replace(tzinfo=UTC), dt) 

def test_aware_datetime_in_utc(self):
        dt = datetime.datetime(2011, 9, 1, 10, 20, 30, tzinfo=UTC)

        data = serializers.serialize('python', [Event(dt=dt)])
        self.assert_python_contains_datetime(data, dt)
        obj = next(serializers.deserialize('python', data)).object
        self.assertEqual(obj.dt, dt)

        data = serializers.serialize('json', [Event(dt=dt)])
        self.assert_json_contains_datetime(data, "2011-09-01T10:20:30Z")
        obj = next(serializers.deserialize('json', data)).object
        self.assertEqual(obj.dt, dt)

        data = serializers.serialize('xml', [Event(dt=dt)])
        self.assert_xml_contains_datetime(data, "2011-09-01T10:20:30+00:00")
        obj = next(serializers.deserialize('xml', data)).object
        self.assertEqual(obj.dt, dt)

        if not isinstance(serializers.get_serializer('yaml'), serializers.BadSerializer):
            data = serializers.serialize('yaml', [Event(dt=dt)])
            self.assert_yaml_contains_datetime(data, "2011-09-01 10:20:30+00:00")
            obj = next(serializers.deserialize('yaml', data)).object
            self.assertEqual(obj.dt.replace(tzinfo=UTC), dt) 

def test_nk_deserialize(self):
        """
        Test for ticket #13030 - Python based parser version
        natural keys deserialize with fk to inheriting model
        """
        management.call_command(
            'loaddata',
            'model-inheritance.json',
            verbosity=0,
        )
        management.call_command(
            'loaddata',
            'nk-inheritance.json',
            verbosity=0,
        )
        self.assertEqual(
            NKChild.objects.get(pk=1).data,
            'apple'
        )

        self.assertEqual(
            RefToNKChild.objects.get(pk=1).nk_fk.data,
            'apple'
        ) 

def test_altering_serialized_output(self):
        """
        The ability to create new objects by modifying serialized content.
        """
        old_headline = "Poker has no place on ESPN"
        new_headline = "Poker has no place on television"
        serial_str = serializers.serialize(self.serializer_name, Article.objects.all())
        serial_str = serial_str.replace(old_headline, new_headline)
        models = list(serializers.deserialize(self.serializer_name, serial_str))

        # Prior to saving, old headline is in place
        self.assertTrue(Article.objects.filter(headline=old_headline))
        self.assertFalse(Article.objects.filter(headline=new_headline))

        for model in models:
            model.save()

        # After saving, new headline is in place
        self.assertTrue(Article.objects.filter(headline=new_headline))
        self.assertFalse(Article.objects.filter(headline=old_headline)) 

def test_forward_refs(self):
        """
        Objects ids can be referenced before they are
        defined in the serialization data.
        """
        # The deserialization process needs to run in a transaction in order
        # to test forward reference handling.
        with transaction.atomic():
            objs = serializers.deserialize(self.serializer_name, self.fwd_ref_str)
            with connection.constraint_checks_disabled():
                for obj in objs:
                    obj.save()

        for model_cls in (Category, Author, Article):
            self.assertEqual(model_cls.objects.all().count(), 1)
        art_obj = Article.objects.all()[0]
        self.assertEqual(art_obj.categories.all().count(), 1)
        self.assertEqual(art_obj.author.name, "Agnes") 

def natural_key_serializer_test(self, format):
    # Create all the objects defined in the test data
    with connection.constraint_checks_disabled():
        objects = [
            NaturalKeyAnchor.objects.create(id=1100, data="Natural Key Anghor"),
            FKDataNaturalKey.objects.create(id=1101, data_id=1100),
            FKDataNaturalKey.objects.create(id=1102, data_id=None),
        ]
    # Serialize the test database
    serialized_data = serializers.serialize(format, objects, indent=2, use_natural_foreign_keys=True)

    for obj in serializers.deserialize(format, serialized_data):
        obj.save()

    # Assert that the deserialized data is the same
    # as the original source
    for obj in objects:
        instance = obj.__class__.objects.get(id=obj.pk)
        self.assertEqual(
            obj.data, instance.data,
            "Objects with PK=%d not equal; expected '%s' (%s), got '%s' (%s)" % (
                obj.pk, obj.data, type(obj.data), instance, type(instance.data),
            )
        ) 

def test_helpful_error_message_invalid_pk(self):
        """
        If there is an invalid primary key, the error message should contain
        the model associated with it.
        """
        test_string = """[{
            "pk": "badpk",
            "model": "serializers.player",
            "fields": {
                "name": "Bob",
                "rank": 1,
                "team": "Team"
            }
        }]"""
        with self.assertRaisesMessage(DeserializationError, "(serializers.player:pk=badpk)"):
            list(serializers.deserialize('json', test_string)) 

def test_helpful_error_message_invalid_field(self):
        """
        If there is an invalid field value, the error message should contain
        the model associated with it.
        """
        test_string = """[{
            "pk": "1",
            "model": "serializers.player",
            "fields": {
                "name": "Bob",
                "rank": "invalidint",
                "team": "Team"
            }
        }]"""
        expected = "(serializers.player:pk=1) field_value was 'invalidint'"
        with self.assertRaisesMessage(DeserializationError, expected):
            list(serializers.deserialize('json', test_string)) 

def test_helpful_error_message_for_foreign_keys(self):
        """
        Invalid foreign keys with a natural key should throw a helpful error
        message, such as what the failing key is.
        """
        test_string = """[{
            "pk": 1,
            "model": "serializers.category",
            "fields": {
                "name": "Unknown foreign key",
                "meta_data": [
                    "doesnotexist",
                    "metadata"
                ]
            }
        }]"""
        key = ["doesnotexist", "metadata"]
        expected = "(serializers.category:pk=1) field_value was '%r'" % key
        with self.assertRaisesMessage(DeserializationError, expected):
            list(serializers.deserialize('json', test_string)) 

def test_aware_datetime_in_local_timezone(self):
        dt = datetime.datetime(2011, 9, 1, 13, 20, 30, tzinfo=EAT)

        data = serializers.serialize('python', [Event(dt=dt)])
        self.assert_python_contains_datetime(data, dt)
        obj = next(serializers.deserialize('python', data)).object
        self.assertEqual(obj.dt, dt)

        data = serializers.serialize('json', [Event(dt=dt)])
        self.assert_json_contains_datetime(data, "2011-09-01T13:20:30+03:00")
        obj = next(serializers.deserialize('json', data)).object
        self.assertEqual(obj.dt, dt)

        data = serializers.serialize('xml', [Event(dt=dt)])
        self.assert_xml_contains_datetime(data, "2011-09-01T13:20:30+03:00")
        obj = next(serializers.deserialize('xml', data)).object
        self.assertEqual(obj.dt, dt)

        if not isinstance(serializers.get_serializer('yaml'), serializers.BadSerializer):
            data = serializers.serialize('yaml', [Event(dt=dt)])
            self.assert_yaml_contains_datetime(data, "2011-09-01 13:20:30+03:00")
            obj = next(serializers.deserialize('yaml', data)).object
            self.assertEqual(obj.dt.replace(tzinfo=UTC), dt) 

def test_naive_datetime(self):
        dt = datetime.datetime(2011, 9, 1, 13, 20, 30)

        data = serializers.serialize('python', [Event(dt=dt)])
        self.assert_python_contains_datetime(data, dt)
        obj = next(serializers.deserialize('python', data)).object
        self.assertEqual(obj.dt, dt)

        data = serializers.serialize('json', [Event(dt=dt)])
        self.assert_json_contains_datetime(data, "2011-09-01T13:20:30")
        obj = next(serializers.deserialize('json', data)).object
        self.assertEqual(obj.dt, dt)

        data = serializers.serialize('xml', [Event(dt=dt)])
        self.assert_xml_contains_datetime(data, "2011-09-01T13:20:30")
        obj = next(serializers.deserialize('xml', data)).object
        self.assertEqual(obj.dt, dt)

        if not isinstance(serializers.get_serializer('yaml'), serializers.BadSerializer):
            data = serializers.serialize('yaml', [Event(dt=dt)])
            self.assert_yaml_contains_datetime(data, "2011-09-01 13:20:30")
            obj = next(serializers.deserialize('yaml', data)).object
            self.assertEqual(obj.dt, dt) 

def test_naive_datetime(self):
        dt = datetime.datetime(2011, 9, 1, 13, 20, 30)

        data = serializers.serialize('python', [Event(dt=dt)])
        self.assert_python_contains_datetime(data, dt)
        obj = next(serializers.deserialize('python', data)).object
        self.assertEqual(obj.dt, dt)

        data = serializers.serialize('json', [Event(dt=dt)])
        self.assert_json_contains_datetime(data, "2011-09-01T13:20:30")
        obj = next(serializers.deserialize('json', data)).object
        self.assertEqual(obj.dt, dt)

        data = serializers.serialize('xml', [Event(dt=dt)])
        self.assert_xml_contains_datetime(data, "2011-09-01T13:20:30")
        obj = next(serializers.deserialize('xml', data)).object
        self.assertEqual(obj.dt, dt)

        if not isinstance(serializers.get_serializer('yaml'), serializers.BadSerializer):
            data = serializers.serialize('yaml', [Event(dt=dt)], default_flow_style=None)
            self.assert_yaml_contains_datetime(data, "2011-09-01 13:20:30")
            obj = next(serializers.deserialize('yaml', data)).object
            self.assertEqual(obj.dt, dt) 

def test_loading(self):
        instance = list(serializers.deserialize('json', self.test_data))[0].object
        self.assertEqual(instance.ints, NumericRange(0, 10))
        self.assertEqual(instance.floats, NumericRange(empty=True))
        self.assertIsNone(instance.bigints)
        self.assertEqual(instance.dates, DateRange(self.lower_date, self.upper_date))
        self.assertEqual(instance.timestamps, DateTimeTZRange(self.lower_dt, self.upper_dt)) 

def deserialize_db_from_string(self, data):
        """
        Reload the database with data from a string generated by
        the serialize_db_to_string() method.
        """
        data = StringIO(data)
        for obj in serializers.deserialize("json", data, using=self.connection.alias):
            obj.save() 

def test_one_to_one_as_pk(self):
        """
        If you use your own primary key field (such as a OneToOneField), it
        doesn't appear in the serialized field list - it replaces the pk
        identifier.
        """
        AuthorProfile.objects.create(author=self.joe, date_of_birth=datetime(1970, 1, 1))
        serial_str = serializers.serialize(self.serializer_name, AuthorProfile.objects.all())
        self.assertFalse(self._get_field_values(serial_str, 'author'))

        for obj in serializers.deserialize(self.serializer_name, serial_str):
            self.assertEqual(obj.object.pk, self.joe.pk) 

def test_serialize_with_null_pk(self):
        """
        Serialized data with no primary key results
        in a model instance with no id
        """
        category = Category(name="Reference")
        serial_str = serializers.serialize(self.serializer_name, [category])
        pk_value = self._get_pk_values(serial_str)[0]
        self.assertFalse(pk_value)

        cat_obj = list(serializers.deserialize(self.serializer_name, serial_str))[0].object
        self.assertIsNone(cat_obj.id) 

def test_float_serialization(self):
        """Float values serialize and deserialize intact"""
        sc = Score(score=3.4)
        sc.save()
        serial_str = serializers.serialize(self.serializer_name, [sc])
        deserial_objs = list(serializers.deserialize(self.serializer_name, serial_str))
        self.assertEqual(deserial_objs[0].object.score, Approximate(3.4, places=1)) 

def test_deferred_field_serialization(self):
        author = Author.objects.create(name='Victor Hugo')
        author = Author.objects.defer('name').get(pk=author.pk)
        serial_str = serializers.serialize(self.serializer_name, [author])
        deserial_objs = list(serializers.deserialize(self.serializer_name, serial_str))
        self.assertIsInstance(deserial_objs[0].object, Author) 

def test_pkless_serialized_strings(self):
        """
        Serialized strings without PKs can be turned into models
        """
        deserial_objs = list(serializers.deserialize(self.serializer_name, self.pkless_str))
        for obj in deserial_objs:
            self.assertFalse(obj.object.id)
            obj.save()
        self.assertEqual(Category.objects.all().count(), 5) 

def test_custom_field_serialization(self):
        """Custom fields serialize and deserialize intact"""
        team_str = "Spartak Moskva"
        player = Player()
        player.name = "Soslan Djanaev"
        player.rank = 1
        player.team = Team(team_str)
        player.save()
        serial_str = serializers.serialize(self.serializer_name, Player.objects.all())
        team = self._get_field_values(serial_str, "team")
        self.assertTrue(team)
        self.assertEqual(team[0], team_str)

        deserial_objs = list(serializers.deserialize(self.serializer_name, serial_str))
        self.assertEqual(deserial_objs[0].object.team.to_string(), player.team.to_string())