Python django.db.models.Manager() Examples

def test_custom_default_manager(self):
        new_apps = Apps(['migrations'])

        class Author(models.Model):
            manager1 = models.Manager()
            manager2 = models.Manager()

            class Meta:
                app_label = 'migrations'
                apps = new_apps
                default_manager_name = 'manager2'

        project_state = ProjectState.from_apps(new_apps)
        author_state = project_state.models['migrations', 'author']
        self.assertEqual(author_state.options['default_manager_name'], 'manager2')
        self.assertEqual(author_state.managers, [('manager2', Author.manager1)]) 

def get_object_or_None(model_thing, **kwargs):
    """
    Shortcut to catch the exception thrown by Model.objects.get if nothing is found and
    returns None instead.

    Example:
        obj = get_object_or_None(MyModelClass, id=3)
    """
    if isinstance(model_thing, models.Manager):
        try:
            return model_thing.get(**kwargs)
        except model_thing.model.DoesNotExist:
            return None
    else:
        try:
            return model_thing.objects.get(**kwargs)
        except model_thing.DoesNotExist:
            return None 

def deconstruct(self):
        kwargs = {
            'name': self.name,
            'fields': self.fields,
        }
        if self.options:
            kwargs['options'] = self.options
        if self.bases and self.bases != (models.Model,):
            kwargs['bases'] = self.bases
        if self.managers and self.managers != [('objects', models.Manager())]:
            kwargs['managers'] = self.managers
        return (
            self.__class__.__qualname__,
            [],
            kwargs
        ) 

def get_relation_instance(resource_instance, source, serializer):
    try:
        relation_instance = operator.attrgetter(source)(resource_instance)
    except AttributeError:
        # if the field is not defined on the model then we check the serializer
        # and if no value is there we skip over the field completely
        serializer_method = getattr(serializer, source, None)
        if serializer_method and hasattr(serializer_method, '__call__'):
            relation_instance = serializer_method(resource_instance)
        else:
            return False, None

    if isinstance(relation_instance, Manager):
        relation_instance = relation_instance.all()

    return True, relation_instance 

def deconstruct(self):
        kwargs = {
            'name': self.name,
            'fields': self.fields,
        }
        if self.options:
            kwargs['options'] = self.options
        if self.bases and self.bases != (models.Model,):
            kwargs['bases'] = self.bases
        if self.managers and self.managers != [('objects', models.Manager())]:
            kwargs['managers'] = self.managers
        return (
            self.__class__.__name__,
            [],
            kwargs
        ) 

def deconstruct(self):
        kwargs = {
            'name': self.name,
            'fields': self.fields,
        }
        if self.options:
            kwargs['options'] = self.options
        if self.bases and self.bases != (models.Model,):
            kwargs['bases'] = self.bases
        if self.managers and self.managers != [('objects', models.Manager())]:
            kwargs['managers'] = self.managers
        return (
            self.__class__.__qualname__,
            [],
            kwargs
        ) 

def deconstruct(self):
        kwargs = {
            'name': self.name,
            'fields': self.fields,
        }
        if self.options:
            kwargs['options'] = self.options
        if self.bases and self.bases != (models.Model,):
            kwargs['bases'] = self.bases
        if self.managers and self.managers != [('objects', models.Manager())]:
            kwargs['managers'] = self.managers
        return (
            self.__class__.__name__,
            [],
            kwargs
        ) 

def to_representation(self, data):
        """
        List of object instances -> List of dicts of primitive datatypes.
        """
        # Dealing with nested relationships, data can be a Manager,
        # so, first get a queryset from the Manager if needed
        iterable = data.all() if isinstance(data, models.Manager) else data

        repr_data = OrderedDict(
            {
                "@context": "https://www.w3.org/ns/activitystreams",
                "summary": self.child.verbose_name_plural,
                "type": "Collection",
                "totalItems": len(iterable),
                "items": [self.child.to_representation(item) for item in iterable],
            }
        )
        repr_data.move_to_end("@context", last=False)
        repr_data.move_to_end("items")
        return repr_data 

def deconstruct(self):
        kwargs = {
            'name': self.name,
            'fields': self.fields,
        }
        if self.options:
            kwargs['options'] = self.options
        if self.bases and self.bases != (models.Model,):
            kwargs['bases'] = self.bases
        if self.managers and self.managers != [('objects', models.Manager())]:
            kwargs['managers'] = self.managers
        return (
            self.__class__.__name__,
            [],
            kwargs
        ) 

def deconstruct(self):
        kwargs = {
            'name': self.name,
            'fields': self.fields,
        }
        if self.options:
            kwargs['options'] = self.options
        if self.bases and self.bases != (models.Model,):
            kwargs['bases'] = self.bases
        if self.managers and self.managers != [('objects', models.Manager())]:
            kwargs['managers'] = self.managers
        return (
            self.__class__.__name__,
            [],
            kwargs
        ) 

def follow(obj, path, force_string=False):
    parts = path.split('__') if path else []
    for idx, part in enumerate(parts):
        if hasattr(obj, 'get_%s_display' % part):
            # If the root object has a method to get the display value for this part, we're done (the rest of the path,
            # if any, is ignored).
            return getattr(obj, 'get_%s_display' % part)()
        else:
            # Otherwise, follow the yellow brick road.
            obj = getattr(obj, part, None)
            if isinstance(obj, models.Manager):
                # Managers are a special case - basically, branch and recurse over all objects with the remainder of the
                # path. This means any path with a Manager/ManyToManyField in it will always return a list, which I
                # think makes sense.
                new_path = '__'.join(parts[idx + 1:])
                if new_path:
                    return [follow(o, new_path, force_string=True) for o in obj.all()]
    if force_string and isinstance(obj, models.Model):
        return six.text_type(obj)
    return obj 

def serialize_object(obj, mapping, prepare=None):
    """
    Given a Django model instance and a ``elasticsearch_dsl.Mapping`` or ``elasticsearch_dsl.InnerObject``, returns a
    dictionary of field data that should be indexed.
    """
    data = {}
    for name in mapping:
        prep_func = getattr(prepare, 'prepare_%s' % name, None)
        if prep_func:
            data[name] = prep_func(obj)
        else:
            field = mapping[name]
            value = follow(obj, name)
            if value is not None:
                if isinstance(value, models.Model):
                    data[name] = serialize_object(value, field.properties) if isinstance(field, InnerObject) else six.text_type(value)
                elif isinstance(value, models.Manager):
                    if isinstance(field, InnerObject):
                        data[name] = [serialize_object(v, field.properties) for v in value.all()]
                    else:
                        data[name] = [six.text_type(v) for v in value.all()]
                else:
                    data[name] = value
    return data 

def test_custom_default_manager_added_to_the_model_state(self):
        """
        When the default manager of the model is a custom manager,
        it needs to be added to the model state.
        """
        new_apps = Apps(['migrations'])
        custom_manager = models.Manager()

        class Author(models.Model):
            objects = models.TextField()
            authors = custom_manager

            class Meta:
                app_label = 'migrations'
                apps = new_apps

        project_state = ProjectState.from_apps(new_apps)
        author_state = project_state.models['migrations', 'author']
        self.assertEqual(author_state.managers, [('authors', custom_manager)]) 

def test_custom_default_manager_named_objects_with_false_migration_flag(self):
        """
        When a manager is added with a name of 'objects' but it does not
        have `use_in_migrations = True`, no migration should be added to the
        model state (#26643).
        """
        new_apps = Apps(['migrations'])

        class Author(models.Model):
            objects = models.Manager()

            class Meta:
                app_label = 'migrations'
                apps = new_apps

        project_state = ProjectState.from_apps(new_apps)
        author_state = project_state.models['migrations', 'author']
        self.assertEqual(author_state.managers, []) 

def test_custom_default_manager(self):
        new_apps = Apps(['migrations'])

        class Author(models.Model):
            manager1 = models.Manager()
            manager2 = models.Manager()

            class Meta:
                app_label = 'migrations'
                apps = new_apps
                default_manager_name = 'manager2'

        project_state = ProjectState.from_apps(new_apps)
        author_state = project_state.models['migrations', 'author']
        self.assertEqual(author_state.options['default_manager_name'], 'manager2')
        self.assertEqual(author_state.managers, [('manager2', Author.manager1)]) 

def smart_repr(value):
    if isinstance(value, models.Manager):
        return manager_repr(value)

    if isinstance(value, Promise) and value._delegate_text:
        value = force_text(value)

    value = unicode_repr(value)

    # Representations like u'help text'
    # should simply be presented as 'help text'
    if value.startswith("u'") and value.endswith("'"):
        return value[1:]

    # Representations like
    # <django.core.validators.RegexValidator object at 0x1047af050>
    # Should be presented as
    # <django.core.validators.RegexValidator object>
    value = re.sub(' at 0x[0-9A-Fa-f]{4,32}>', '>', value)

    return value 

def test_custom_default_manager_added_to_the_model_state(self):
        """
        When the default manager of the model is a custom manager,
        it needs to be added to the model state.
        """
        new_apps = Apps(['migrations'])
        custom_manager = models.Manager()

        class Author(models.Model):
            objects = models.TextField()
            authors = custom_manager

            class Meta:
                app_label = 'migrations'
                apps = new_apps

        project_state = ProjectState.from_apps(new_apps)
        author_state = project_state.models['migrations', 'author']
        self.assertEqual(author_state.managers, [('authors', custom_manager)]) 

def test_custom_default_manager_named_objects_with_false_migration_flag(self):
        """
        When a manager is added with a name of 'objects' but it does not
        have `use_in_migrations = True`, no migration should be added to the
        model state (#26643).
        """
        new_apps = Apps(['migrations'])

        class Author(models.Model):
            objects = models.Manager()

            class Meta:
                app_label = 'migrations'
                apps = new_apps

        project_state = ProjectState.from_apps(new_apps)
        author_state = project_state.models['migrations', 'author']
        self.assertEqual(author_state.managers, []) 

def test_create_model(self):
        """
        Tests the CreateModel operation.
        Most other tests use this operation as part of setup, so check failures here first.
        """
        operation = migrations.CreateModel(
            "Pony",
            [
                ("id", models.AutoField(primary_key=True)),
                ("pink", models.IntegerField(default=1)),
            ],
        )
        self.assertEqual(operation.describe(), "Create model Pony")
        # Test the state alteration
        project_state = ProjectState()
        new_state = project_state.clone()
        operation.state_forwards("test_crmo", new_state)
        self.assertEqual(new_state.models["test_crmo", "pony"].name, "Pony")
        self.assertEqual(len(new_state.models["test_crmo", "pony"].fields), 2)
        # Test the database alteration
        self.assertTableNotExists("test_crmo_pony")
        with connection.schema_editor() as editor:
            operation.database_forwards("test_crmo", editor, project_state, new_state)
        self.assertTableExists("test_crmo_pony")
        # And test reversal
        with connection.schema_editor() as editor:
            operation.database_backwards("test_crmo", editor, new_state, project_state)
        self.assertTableNotExists("test_crmo_pony")
        # And deconstruction
        definition = operation.deconstruct()
        self.assertEqual(definition[0], "CreateModel")
        self.assertEqual(definition[1], [])
        self.assertEqual(sorted(definition[2].keys()), ["fields", "name"])
        # And default manager not in set
        operation = migrations.CreateModel("Foo", fields=[], managers=[("objects", models.Manager())])
        definition = operation.deconstruct()
        self.assertNotIn('managers', definition[2]) 

def test_serialize_managers(self):
        self.assertSerializedEqual(models.Manager())
        self.assertSerializedResultEqual(
            FoodQuerySet.as_manager(),
            ('migrations.models.FoodQuerySet.as_manager()', {'import migrations.models'})
        )
        self.assertSerializedEqual(FoodManager('a', 'b'))
        self.assertSerializedEqual(FoodManager('x', 'y', c=3, d=4)) 

def test_custom_base_manager(self):
        new_apps = Apps(['migrations'])

        class Author(models.Model):
            manager1 = models.Manager()
            manager2 = models.Manager()

            class Meta:
                app_label = 'migrations'
                apps = new_apps
                base_manager_name = 'manager2'

        class Author2(models.Model):
            manager1 = models.Manager()
            manager2 = models.Manager()

            class Meta:
                app_label = 'migrations'
                apps = new_apps
                base_manager_name = 'manager1'

        project_state = ProjectState.from_apps(new_apps)

        author_state = project_state.models['migrations', 'author']
        self.assertEqual(author_state.options['base_manager_name'], 'manager2')
        self.assertEqual(author_state.managers, [
            ('manager1', Author.manager1),
            ('manager2', Author.manager2),
        ])

        author2_state = project_state.models['migrations', 'author2']
        self.assertEqual(author2_state.options['base_manager_name'], 'manager1')
        self.assertEqual(author2_state.managers, [
            ('manager1', Author2.manager1),
        ]) 

def test_create_model_with_duplicate_manager_name(self):
        with self.assertRaisesMessage(ValueError, 'Found duplicate value objects in CreateModel managers argument.'):
            migrations.CreateModel(
                "Pony",
                fields=[],
                managers=[
                    ("objects", models.Manager()),
                    ("objects", models.Manager()),
                ],
            ) 

def test_alter_model_managers(self):
        """
        The managers on a model are set.
        """
        project_state = self.set_up_test_model("test_almoma")
        # Test the state alteration
        operation = migrations.AlterModelManagers(
            "Pony",
            managers=[
                ("food_qs", FoodQuerySet.as_manager()),
                ("food_mgr", FoodManager("a", "b")),
                ("food_mgr_kwargs", FoodManager("x", "y", 3, 4)),
            ]
        )
        self.assertEqual(operation.describe(), "Change managers on Pony")
        managers = project_state.models["test_almoma", "pony"].managers
        self.assertEqual(managers, [])

        new_state = project_state.clone()
        operation.state_forwards("test_almoma", new_state)
        self.assertIn(("test_almoma", "pony"), new_state.models)
        managers = new_state.models["test_almoma", "pony"].managers
        self.assertEqual(managers[0][0], "food_qs")
        self.assertIsInstance(managers[0][1], models.Manager)
        self.assertEqual(managers[1][0], "food_mgr")
        self.assertIsInstance(managers[1][1], FoodManager)
        self.assertEqual(managers[1][1].args, ("a", "b", 1, 2))
        self.assertEqual(managers[2][0], "food_mgr_kwargs")
        self.assertIsInstance(managers[2][1], FoodManager)
        self.assertEqual(managers[2][1].args, ("x", "y", 3, 4))
        rendered_state = new_state.apps
        model = rendered_state.get_model('test_almoma', 'pony')
        self.assertIsInstance(model.food_qs, models.Manager)
        self.assertIsInstance(model.food_mgr, FoodManager)
        self.assertIsInstance(model.food_mgr_kwargs, FoodManager) 

def get_queryset(self):
            return super().get_queryset().filter(category=None).exclude(title='')

    # The first Manager in a class is used as default 

def get_queryset(self):
            return super().get_queryset().filter(nop_team=False)

    # The first Manager in a class is used as default 

def get_queryset(self):
            return super().get_queryset().filter(category=None).exclude(title='')

    # The first Manager in a class is used as default 

def get_queryset(self):
            return super().get_queryset().filter(category=None).exclude(title='')

    # The first Manager in a class is used as default 

def get_queryset(self):
            return super().get_queryset().filter(nop_team=False)

    # The first Manager in a class is used as default 

def get_queryset(self):
            return super().get_queryset().filter(category=None).exclude(title='')

    # The first Manager in a class is used as default 

def get_queryset(self):
            return super().get_queryset().filter(category=None).exclude(title='')

    # The first Manager in a class is used as default