Serializer relations - Django REST framework (2023)

relations.py

Data structures, not algorithms, are central to programming.

Rob Pike

Relational fields are used to represent model relationships. They can be applied to ForeignKey, ManyToManyField and OneToOneField relationships, as well as to reverse relationships, and custom relationships such as GenericForeignKey.

Note: The relational fields are declared in relations.py, but by convention you should import them from the serializers module, using from rest_framework import serializers and refer to fields as serializers.<FieldName>.

Note: REST Framework does not attempt to automatically optimize querysets passed to serializers in terms of select_related and prefetch_related since it would be too much magic. A serializer with a field spanning an orm relation through its source attribute could require an additional database hit to fetch related objects from the database. It is the programmer's responsibility to optimize queries to avoid additional database hits which could occur while using such a serializer.

For example, the following serializer would lead to a database hit each time evaluating the tracks field if it is not prefetched:

class AlbumSerializer(serializers.ModelSerializer): tracks = serializers.SlugRelatedField( many=True, read_only=True, slug_field='title' ) class Meta: model = Album fields = ['album_name', 'artist', 'tracks']# For each album object, tracks should be fetched from databaseqs = Album.objects.all()print(AlbumSerializer(qs, many=True).data)

If AlbumSerializer is used to serialize a fairly large queryset with many=True then it could be a serious performance problem. Optimizing the queryset passed to AlbumSerializer with:

qs = Album.objects.prefetch_related('tracks')# No additional database hits requiredprint(AlbumSerializer(qs, many=True).data)

would solve the issue.

Inspecting relationships.

When using the ModelSerializer class, serializer fields and relationships will be automatically generated for you. Inspecting these automatically generated fields can be a useful tool for determining how to customize the relationship style.

To do so, open the Django shell, using python manage.py shell, then import the serializer class, instantiate it, and print the object representation…

>>> from myapp.serializers import AccountSerializer>>> serializer = AccountSerializer()>>> print(repr(serializer))AccountSerializer(): id = IntegerField(label='ID', read_only=True) name = CharField(allow_blank=True, max_length=100, required=False) owner = PrimaryKeyRelatedField(queryset=User.objects.all())

In order to explain the various types of relational fields, we'll use a couple of simple models for our examples. Our models will be for music albums, and the tracks listed on each album.

class Album(models.Model): album_name = models.CharField(max_length=100) artist = models.CharField(max_length=100)class Track(models.Model): album = models.ForeignKey(Album, related_name='tracks', on_delete=models.CASCADE) order = models.IntegerField() title = models.CharField(max_length=100) duration = models.IntegerField() class Meta: unique_together = ['album', 'order'] ordering = ['order'] def __str__(self): return '%d: %s' % (self.order, self.title)

StringRelatedField may be used to represent the target of the relationship using its __str__ method.

For example, the following serializer:

class AlbumSerializer(serializers.ModelSerializer): tracks = serializers.StringRelatedField(many=True) class Meta: model = Album fields = ['album_name', 'artist', 'tracks']

Would serialize to the following representation:

{ 'album_name': 'Things We Lost In The Fire', 'artist': 'Low', 'tracks': [ '1: Sunflower', '2: Whitetail', '3: Dinosaur Act', ... ]}

This field is read only.

Arguments:

  • many - If applied to a to-many relationship, you should set this argument to True.

PrimaryKeyRelatedField

PrimaryKeyRelatedField may be used to represent the target of the relationship using its primary key.

(Video) Serializer Relationships (Using Nested Serializers) | Learn Django REST Framework #11

For example, the following serializer:

class AlbumSerializer(serializers.ModelSerializer): tracks = serializers.PrimaryKeyRelatedField(many=True, read_only=True) class Meta: model = Album fields = ['album_name', 'artist', 'tracks']

Would serialize to a representation like this:

{ 'album_name': 'Undun', 'artist': 'The Roots', 'tracks': [ 89, 90, 91, ... ]}

By default this field is read-write, although you can change this behavior using the read_only flag.

Arguments:

  • queryset - The queryset used for model instance lookups when validating the field input. Relationships must either set a queryset explicitly, or set read_only=True.
  • many - If applied to a to-many relationship, you should set this argument to True.
  • allow_null - If set to True, the field will accept values of None or the empty string for nullable relationships. Defaults to False.
  • pk_field - Set to a field to control serialization/deserialization of the primary key's value. For example, pk_field=UUIDField(format='hex') would serialize a UUID primary key into its compact hex representation.

HyperlinkedRelatedField may be used to represent the target of the relationship using a hyperlink.

For example, the following serializer:

class AlbumSerializer(serializers.ModelSerializer): tracks = serializers.HyperlinkedRelatedField( many=True, read_only=True, view_name='track-detail' ) class Meta: model = Album fields = ['album_name', 'artist', 'tracks']

Would serialize to a representation like this:

{ 'album_name': 'Graceland', 'artist': 'Paul Simon', 'tracks': [ 'http://www.example.com/api/tracks/45/', 'http://www.example.com/api/tracks/46/', 'http://www.example.com/api/tracks/47/', ... ]}

By default this field is read-write, although you can change this behavior using the read_only flag.

Note: This field is designed for objects that map to a URL that accepts a single URL keyword argument, as set using the lookup_field and lookup_url_kwarg arguments.

This is suitable for URLs that contain a single primary key or slug argument as part of the URL.

If you require more complex hyperlinked representation you'll need to customize the field, as described in the custom hyperlinked fields section, below.

Arguments:

  • view_name - The view name that should be used as the target of the relationship. If you're using the standard router classes this will be a string with the format <modelname>-detail. required.
  • queryset - The queryset used for model instance lookups when validating the field input. Relationships must either set a queryset explicitly, or set read_only=True.
  • many - If applied to a to-many relationship, you should set this argument to True.
  • allow_null - If set to True, the field will accept values of None or the empty string for nullable relationships. Defaults to False.
  • lookup_field - The field on the target that should be used for the lookup. Should correspond to a URL keyword argument on the referenced view. Default is 'pk'.
  • lookup_url_kwarg - The name of the keyword argument defined in the URL conf that corresponds to the lookup field. Defaults to using the same value as lookup_field.
  • format - If using format suffixes, hyperlinked fields will use the same format suffix for the target unless overridden by using the format argument.

SlugRelatedField

SlugRelatedField may be used to represent the target of the relationship using a field on the target.

For example, the following serializer:

class AlbumSerializer(serializers.ModelSerializer): tracks = serializers.SlugRelatedField( many=True, read_only=True, slug_field='title' ) class Meta: model = Album fields = ['album_name', 'artist', 'tracks']

Would serialize to a representation like this:

{ 'album_name': 'Dear John', 'artist': 'Loney Dear', 'tracks': [ 'Airport Surroundings', 'Everything Turns to You', 'I Was Only Going Out', ... ]}

By default this field is read-write, although you can change this behavior using the read_only flag.

When using SlugRelatedField as a read-write field, you will normally want to ensure that the slug field corresponds to a model field with unique=True.

Arguments:

(Video) Django Rest Framework API #29 / represent relationships using Serializer StringRelatedField.

  • slug_field - The field on the target that should be used to represent it. This should be a field that uniquely identifies any given instance. For example, username. required
  • queryset - The queryset used for model instance lookups when validating the field input. Relationships must either set a queryset explicitly, or set read_only=True.
  • many - If applied to a to-many relationship, you should set this argument to True.
  • allow_null - If set to True, the field will accept values of None or the empty string for nullable relationships. Defaults to False.

HyperlinkedIdentityField

This field can be applied as an identity relationship, such as the 'url' field on a HyperlinkedModelSerializer. It can also be used for an attribute on the object. For example, the following serializer:

class AlbumSerializer(serializers.HyperlinkedModelSerializer): track_listing = serializers.HyperlinkedIdentityField(view_name='track-list') class Meta: model = Album fields = ['album_name', 'artist', 'track_listing']

Would serialize to a representation like this:

{ 'album_name': 'The Eraser', 'artist': 'Thom Yorke', 'track_listing': 'http://www.example.com/api/track_list/12/',}

This field is always read-only.

Arguments:

  • view_name - The view name that should be used as the target of the relationship. If you're using the standard router classes this will be a string with the format <model_name>-detail. required.
  • lookup_field - The field on the target that should be used for the lookup. Should correspond to a URL keyword argument on the referenced view. Default is 'pk'.
  • lookup_url_kwarg - The name of the keyword argument defined in the URL conf that corresponds to the lookup field. Defaults to using the same value as lookup_field.
  • format - If using format suffixes, hyperlinked fields will use the same format suffix for the target unless overridden by using the format argument.

As opposed to previously discussed references to another entity, the referred entity can instead also be embedded or nestedin the representation of the object that refers to it.Such nested relationships can be expressed by using serializers as fields.

If the field is used to represent a to-many relationship, you should add the many=True flag to the serializer field.

Example

For example, the following serializer:

class TrackSerializer(serializers.ModelSerializer): class Meta: model = Track fields = ['order', 'title', 'duration']class AlbumSerializer(serializers.ModelSerializer): tracks = TrackSerializer(many=True, read_only=True) class Meta: model = Album fields = ['album_name', 'artist', 'tracks']

Would serialize to a nested representation like this:

>>> album = Album.objects.create(album_name="The Grey Album", artist='Danger Mouse')>>> Track.objects.create(album=album, order=1, title='Public Service Announcement', duration=245)<Track: Track object>>>> Track.objects.create(album=album, order=2, title='What More Can I Say', duration=264)<Track: Track object>>>> Track.objects.create(album=album, order=3, title='Encore', duration=159)<Track: Track object>>>> serializer = AlbumSerializer(instance=album)>>> serializer.data{ 'album_name': 'The Grey Album', 'artist': 'Danger Mouse', 'tracks': [ {'order': 1, 'title': 'Public Service Announcement', 'duration': 245}, {'order': 2, 'title': 'What More Can I Say', 'duration': 264}, {'order': 3, 'title': 'Encore', 'duration': 159}, ... ],}

Writable nested serializers

By default nested serializers are read-only. If you want to support write-operations to a nested serializer field you'll need to create create() and/or update() methods in order to explicitly specify how the child relationships should be saved:

class TrackSerializer(serializers.ModelSerializer): class Meta: model = Track fields = ['order', 'title', 'duration']class AlbumSerializer(serializers.ModelSerializer): tracks = TrackSerializer(many=True) class Meta: model = Album fields = ['album_name', 'artist', 'tracks'] def create(self, validated_data): tracks_data = validated_data.pop('tracks') album = Album.objects.create(**validated_data) for track_data in tracks_data: Track.objects.create(album=album, **track_data) return album>>> data = { 'album_name': 'The Grey Album', 'artist': 'Danger Mouse', 'tracks': [ {'order': 1, 'title': 'Public Service Announcement', 'duration': 245}, {'order': 2, 'title': 'What More Can I Say', 'duration': 264}, {'order': 3, 'title': 'Encore', 'duration': 159}, ],}>>> serializer = AlbumSerializer(data=data)>>> serializer.is_valid()True>>> serializer.save()<Album: Album object>

In rare cases where none of the existing relational styles fit the representation you need,you can implement a completely custom relational field, that describes exactly how theoutput representation should be generated from the model instance.

To implement a custom relational field, you should override RelatedField, and implement the .to_representation(self, value) method. This method takes the target of the field as the value argument, and should return the representation that should be used to serialize the target. The value argument will typically be a model instance.

If you want to implement a read-write relational field, you must also implement the .to_internal_value(self, data) method.

To provide a dynamic queryset based on the context, you can also override .get_queryset(self) instead of specifying .queryset on the class or when initializing the field.

Example

For example, we could define a relational field to serialize a track to a custom string representation, using its ordering, title, and duration:

import timeclass TrackListingField(serializers.RelatedField): def to_representation(self, value): duration = time.strftime('%M:%S', time.gmtime(value.duration)) return 'Track %d: %s (%s)' % (value.order, value.name, duration)class AlbumSerializer(serializers.ModelSerializer): tracks = TrackListingField(many=True) class Meta: model = Album fields = ['album_name', 'artist', 'tracks']

This custom field would then serialize to the following representation:

{ 'album_name': 'Sometimes I Wish We Were an Eagle', 'artist': 'Bill Callahan', 'tracks': [ 'Track 1: Jim Cain (04:39)', 'Track 2: Eid Ma Clack Shaw (04:19)', 'Track 3: The Wind and the Dove (04:34)', ... ]}

In some cases you may need to customize the behavior of a hyperlinked field, in order to represent URLs that require more than a single lookup field.

You can achieve this by overriding HyperlinkedRelatedField. There are two methods that may be overridden:

get_url(self, obj, view_name, request, format)

(Video) Serializer Relations in Django REST Framework - How to use Serializer Relations in DRF - English

The get_url method is used to map the object instance to its URL representation.

May raise a NoReverseMatch if the view_name and lookup_fieldattributes are not configured to correctly match the URL conf.

get_object(self, view_name, view_args, view_kwargs)

If you want to support a writable hyperlinked field then you'll also want to override get_object, in order to map incoming URLs back to the object they represent. For read-only hyperlinked fields there is no need to override this method.

The return value of this method should the object that corresponds to the matched URL conf arguments.

May raise an ObjectDoesNotExist exception.

Example

Say we have a URL for a customer object that takes two keyword arguments, like so:

/api/<organization_slug>/customers/<customer_pk>/

This cannot be represented with the default implementation, which accepts only a single lookup field.

In this case we'd need to override HyperlinkedRelatedField to get the behavior we want:

from rest_framework import serializersfrom rest_framework.reverse import reverseclass CustomerHyperlink(serializers.HyperlinkedRelatedField): # We define these as class attributes, so we don't need to pass them as arguments. view_name = 'customer-detail' queryset = Customer.objects.all() def get_url(self, obj, view_name, request, format): url_kwargs = { 'organization_slug': obj.organization.slug, 'customer_pk': obj.pk } return reverse(view_name, kwargs=url_kwargs, request=request, format=format) def get_object(self, view_name, view_args, view_kwargs): lookup_kwargs = { 'organization__slug': view_kwargs['organization_slug'], 'pk': view_kwargs['customer_pk'] } return self.get_queryset().get(**lookup_kwargs)

Note that if you wanted to use this style together with the generic views then you'd also need to override .get_object on the view in order to get the correct lookup behavior.

Generally we recommend a flat style for API representations where possible, but the nested URL style can also be reasonable when used in moderation.

The queryset argument

The queryset argument is only ever required for writable relationship field, in which case it is used for performing the model instance lookup, that maps from the primitive user input, into a model instance.

In version 2.x a serializer class could sometimes automatically determine the queryset argument if a ModelSerializer class was being used.

This behavior is now replaced with always using an explicit queryset argument for writable relational fields.

Doing so reduces the amount of hidden 'magic' that ModelSerializer provides, makes the behavior of the field more clear, and ensures that it is trivial to move between using the ModelSerializer shortcut, or using fully explicit Serializer classes.

Customizing the HTML display

The built-in __str__ method of the model will be used to generate string representations of the objects used to populate the choices property. These choices are used to populate select HTML inputs in the browsable API.

To provide customized representations for such inputs, override display_value() of a RelatedField subclass. This method will receive a model object, and should return a string suitable for representing it. For example:

class TrackPrimaryKeyRelatedField(serializers.PrimaryKeyRelatedField): def display_value(self, instance): return 'Track: %s' % (instance.title)

Select field cutoffs

When rendered in the browsable API relational fields will default to only displaying a maximum of 1000 selectable items. If more items are present then a disabled option with "More than 1000 items…" will be displayed.

(Video) Django Rest Framework API #16 / Many To One Relationship, Nested Data

This behavior is intended to prevent a template from being unable to render in an acceptable timespan due to a very large number of relationships being displayed.

There are two keyword arguments you can use to control this behavior:

  • html_cutoff - If set this will be the maximum number of choices that will be displayed by a HTML select drop down. Set to None to disable any limiting. Defaults to 1000.
  • html_cutoff_text - If set this will display a textual indicator if the maximum number of items have been cutoff in an HTML select drop down. Defaults to "More than {count} items…"

You can also control these globally using the settings HTML_SELECT_CUTOFF and HTML_SELECT_CUTOFF_TEXT.

In cases where the cutoff is being enforced you may want to instead use a plain input field in the HTML form. You can do so using the style keyword argument. For example:

assigned_to = serializers.SlugRelatedField( queryset=User.objects.all(), slug_field='username', style={'base_template': 'input.html'})

Reverse relations

Note that reverse relationships are not automatically included by the ModelSerializer and HyperlinkedModelSerializer classes. To include a reverse relationship, you must explicitly add it to the fields list. For example:

class AlbumSerializer(serializers.ModelSerializer): class Meta: fields = ['tracks', ...]

You'll normally want to ensure that you've set an appropriate related_name argument on the relationship, that you can use as the field name. For example:

class Track(models.Model): album = models.ForeignKey(Album, related_name='tracks', on_delete=models.CASCADE) ...

If you have not set a related name for the reverse relationship, you'll need to use the automatically generated related name in the fields argument. For example:

class AlbumSerializer(serializers.ModelSerializer): class Meta: fields = ['track_set', ...]

See the Django documentation on reverse relationships for more details.

Generic relationships

If you want to serialize a generic foreign key, you need to define a custom field, to determine explicitly how you want to serialize the targets of the relationship.

For example, given the following model for a tag, which has a generic relationship with other arbitrary models:

class TaggedItem(models.Model): """ Tags arbitrary model instances using a generic relation. See: https://docs.djangoproject.com/en/stable/ref/contrib/contenttypes/ """ tag_name = models.SlugField() content_type = models.ForeignKey(ContentType, on_delete=models.CASCADE) object_id = models.PositiveIntegerField() tagged_object = GenericForeignKey('content_type', 'object_id') def __str__(self): return self.tag_name

And the following two models, which may have associated tags:

class Bookmark(models.Model): """ A bookmark consists of a URL, and 0 or more descriptive tags. """ url = models.URLField() tags = GenericRelation(TaggedItem)class Note(models.Model): """ A note consists of some text, and 0 or more descriptive tags. """ text = models.CharField(max_length=1000) tags = GenericRelation(TaggedItem)

We could define a custom field that could be used to serialize tagged instances, using the type of each instance to determine how it should be serialized:

class TaggedObjectRelatedField(serializers.RelatedField): """ A custom field to use for the `tagged_object` generic relationship. """ def to_representation(self, value): """ Serialize tagged objects to a simple textual representation. """ if isinstance(value, Bookmark): return 'Bookmark: ' + value.url elif isinstance(value, Note): return 'Note: ' + value.text raise Exception('Unexpected type of tagged object')

If you need the target of the relationship to have a nested representation, you can use the required serializers inside the .to_representation() method:

 def to_representation(self, value): """ Serialize bookmark instances using a bookmark serializer, and note instances using a note serializer. """ if isinstance(value, Bookmark): serializer = BookmarkSerializer(value) elif isinstance(value, Note): serializer = NoteSerializer(value) else: raise Exception('Unexpected type of tagged object') return serializer.data

Note that reverse generic keys, expressed using the GenericRelation field, can be serialized using the regular relational field types, since the type of the target in the relationship is always known.

For more information see the Django documentation on generic relations.

ManyToManyFields with a Through Model

By default, relational fields that target a ManyToManyField with athrough model specified are set to read-only.

If you explicitly specify a relational field pointing to aManyToManyField with a through model, be sure to set read_onlyto True.

If you wish to represent extra fields on a through model then you may serialize the through model as a nested object.

(Video) Serializer Relations in Django REST Framework (Hindi)

The following third party packages are also available.

DRF Nested Routers

The drf-nested-routers package provides routers and relationship fields for working with nested resources.

Rest Framework Generic Relations

The rest-framework-generic-relations library provides read/write serialization for generic foreign keys.

FAQs

Do we need Serializers in Django REST Framework? ›

Serializers in Django REST Framework are responsible for converting objects into data types understandable by javascript and front-end frameworks. Serializers also provide deserialization, allowing parsed data to be converted back into complex types, after first validating the incoming data.

How do you pass extra context data to Serializers in Django REST Framework? ›

In function-based views, we can pass extra context to serializer with “context” parameter with a dictionary. To access the extra context data inside the serializer we can simply access it with “self. context”. From example, to get “exclude_email_list” we just used code 'exclude_email_list = self.

How do I know if my serializer is valid? ›

How do I know if my serializer is valid? We can validate the serializer by calling the method " is_valid() ". It will return the boolean(True/False) value. If the serializer is not valid then we can get errors by using the attribute "errors".

Do you need a serializer? ›

It is not necessary to use a serializer. You can do what you would like to achieve in a view. However, serializers help you a lot. If you don't want to use serializer, you can inherit APIView at a function-based-view.

Why do we need serialization in REST API? ›

Serialization is a conversion of the state of a Java object to a byte stream and Deserialization is the reverse of it i.e. conversion of a byte stream to corresponding Java object. A serialized object can be stored in files, external sources, databases etc and can also be transferred over networks.

Why do we need JSON serialization? ›

The purpose of serializing it into JSON is so that the message will be a format that can be understood and from there, deserialize it into an object type that makes sense for the consumer.

How do I pass extra data to a serializer? ›

  1. In function based views we can pass extra context to serializer with "context" parameter with a dictionary. ...
  2. It is the best way to override/overload the method get_serializer_context to pass the extra context data to the serializer.
  3. In viewsets, generic views "get_serializer_context" returns the below data by default.
5 Oct 2017

How does django serializer get data? ›

How to Serialize Data With DRF
  1. Step 1: Creating Django Application. We'll start by developing a straightforward Django project. ...
  2. Step 2: Creating Our Models. ...
  3. Step 3: Serializing the Data With Django Rest Framework. ...
  4. Step 4: CRUD Methods & View Function. ...
  5. Step 5: Creating the API Endpoints. ...
  6. Step 6: Serializing Nested Data.

What is the difference between serializer and ModelSerializer? ›

The ModelSerializer class is the same as a regular Serializer class, except that: It will automatically generate a set of fields for you, based on the model. It will automatically generate validators for the serializer, such as unique_together validators. It includes simple default implementations of .

How do you debug a serializer? ›

You can access the window from Tools > Odin Inspector > Serialization Debugger and select your script type from the dropdown to start debugging. Or you can directly start debugging a component by clicking the Debug Serialization button in the component's cogwheel dropdown menu.

How do you call a serializer? ›

Django -> 3 ways to call Serializer
  1. def retrieve(self, request, *args, **kwargs): instance = self. ...
  2. def create(self, request, *args, **kwargs): serializer = ProfileSerializer(data=request. ...
  3. def update(self, request, *args, **kwargs): instance = self.
13 Aug 2021

What is validated data in Django Serializers? ›

validated_data is an OrderedDict and you can see it only after is_valid() and is_valid() == True.

What happen if you dont use serialization? ›

What happens if you try to send non-serialized Object over network? When traversing a graph, an object may be encountered that does not support the Serializable interface. In this case the NotSerializableException will be thrown and will identify the class of the non-serializable object.

Is JSON a serializer? ›

Json namespace provides functionality for serializing to and deserializing from JavaScript Object Notation (JSON). Serialization is the process of converting the state of an object, that is, the values of its properties, into a form that can be stored or transmitted.

What is the benefit of serialization? ›

Serialization allows us to transfer objects through a network by converting it into a byte stream. It also helps in preserving the state of the object. Deserialization requires less time to create an object than an actual object created from a class. hence serialization saves time.

How can we avoid serialization? ›

To avoid Java serialization you need to implement writeObject() and readObject() method in your Class and need to throw NotSerializableException from those method.

What is the difference between parsing and serialization? ›

Use a parser to read XML from a character stream into data structures; use a serializer to write data structures out into a character stream.

What happens when an object is serialized? ›

Serialization is the process of converting an object into a stream of bytes to store the object or transmit it to memory, a database, or a file. Its main purpose is to save the state of an object in order to be able to recreate it when needed. The reverse process is called deserialization.

When should serialization be used? ›

Serialization in Java is the concept of representing an object's state as a byte stream. The byte stream has all the information about the object. Usually used in Hibernate, JMS, JPA, and EJB, serialization in Java helps transport the code from one JVM to another and then de-serialize it there.

How does serialization work in REST API? ›

In Java, Serialization is a process of converting an object from its current state to a stream of bytes which can be written to a file or transported through a network or stored in a database. De-serialization is rebuilding the object from stream of bytes.

Why do we need serialization in Python? ›

- [Instructor] Serialization is the act of taking Python objects, such as dict list, daytime and others, and converting them to a sequence of bytes. On the other side, there's de-serialization, we'll take a sequence of bytes and convert them to a Python objects or several objects.

How do I append extra data to the serializer in Django? ›

You can use SerializerMethodField to add extra data to the serialized representation of an object. This is a read-only field. It gets its value by calling a method on the serializer class it is attached to. It can be used to add any sort of data to the serialized representation of your object.

Why do we need to serialize data? ›

Serialization enables us to save the state of an object and recreate the object in a new location. Serialization encompasses both the storage of the object and exchange of data.

What is depth in Django serializer? ›

DRF allows you to expose a REST framework based on your django data models with very little code needed. To get a basic REST API that supports Create-Read-Update-Delete operations on your data you have to do two things: You specify a serializer that tells drf how to go from your model to a JSON representation.

Is Django REST Framework good? ›

Django REST framework (DRF) is a powerful and flexible toolkit for building Web APIs. Its main benefit is that it makes serialization much easier. Django REST framework is based on Django's class-based views, so it's an excellent option if you're familiar with Django.

What is the difference between Django and Django REST Framework? ›

Django is the web development framework in python whereas the Django Rest Framework is the library used in Django to build Rest APIs. Django Rest Framework is especially designed to make the CRUD operations easier to design in Django. Django Rest Framework makes it easy to use your Django Server as an REST API.

How data is stored in Django REST Framework? ›

1 Answer
  1. First clear your new database - (here new is the name of your database, it is default but you can look it up in settings.py file and use that name) python manage.py flush --database=new.
  2. Export data from the old Database to a json file. python manage.py dumpdata>data.json.
  3. Load Data into the new Database.
28 Feb 2022

What is meta in Django serializer? ›

Model Meta is basically the inner class of your model class. Model Meta is basically used to change the behavior of your model fields like changing order options,verbose_name, and a lot of other options.

What is difference between APIView and ViewSet? ›

APIView allow us to define functions that match standard HTTP methods like GET, POST, PUT, PATCH, etc. Viewsets allow us to define functions that match to common API object actions like : LIST, CREATE, RETRIEVE, UPDATE, etc.

How do I create a custom serializer? ›

The first step in creating a custom serializer is to extend Jackson's JsonSerializer .
...
On a high level, the instructions should like this:
  1. Write the start of a JSON object ( { ).
  2. Write a start field ( "start" : "..." ).
  3. Write an end field ( "end" : "..." ).
  4. Write the end of a JSON object ( } ).
1 Jul 2016

What is serialization with example? ›

Serialization is a mechanism of converting the state of an object into a byte stream. Deserialization is the reverse process where the byte stream is used to recreate the actual Java object in memory. This mechanism is used to persist the object. The byte stream created is platform independent.

How can you prevent a property from being serialized? ›

You can prevent member variables from being serialized by marking them with the NonSerialized attribute as follows. If possible, make an object that could contain security-sensitive data nonserializable. If the object must be serialized, apply the NonSerialized attribute to specific fields that store sensitive data.

What is serializer data? ›

Serialization is the process of turning data (e.g. variables) into a representation such as a string, that can easily be written and read back from for example a file or the database.

Why Django REST framework is used? ›

Main advantages of Django REST framework: Simplicity, flexibility, quality, and test coverage of source code. Powerful serialization engine compatible with both ORM and non-ORM data sources. Pluggable and easy to customise emitters, parsers, validators and authenticators.

What is serialization Django? ›

Django's serialization framework provides a mechanism for “translating” Django models into other formats. Usually these other formats will be text-based and used for sending Django data over a wire, but it's possible for a serializer to handle any format (text-based or not).

How use DRF serializer effectively in Django? ›

This article covers:
  1. Validating data at the field or object level.
  2. Customizing the serialization and deserialization output.
  3. Passing additional data at save.
  4. Passing context to serializers.
  5. Renaming serializer output fields.
  6. Attaching serializer function responses to data.
  7. Fetching data from one-to-one models.
24 Mar 2021

What is payload validation? ›

The Validate Payload Node allows a workflow to check part or all of the current payload against a JSON schema and branch depending on whether the payload passes validation.

How do you validate a dataset? ›

Validation within a dataset is accomplished in the following ways:
  1. By creating your own application-specific validation that can check values in an individual data column during changes. ...
  2. By creating your own application-specific validation that can check data to values while an entire data row is changing.
17 Jun 2022

How does Django validate OTP? ›

Creating and Verifying One-Time Passwords with django-otp.
  1. User enters a phone number to register with.
  2. Generate and send a One-Time Password(OTP) to the registered phone number.
  3. User enters OTP.
  4. If OTP is valid, mark the phone as verified, else throw an error.

Does serialization reduce size? ›

In some cases, the secondary intention of data serialization is to minimize the data's size which then reduces disk space or bandwidth requirements.

Which keywords should avoid serialization? ›

The transient keyword is used to avoid the serialization process, whereas a volatile keyword is used with a variable so that it's not stored toin the main memory.

What should never be serialized? ›

Examples of sensitive data that should never be serialized include cryptographic keys, digital certificates, and classes that may hold references to sensitive data at the time of serialization. This rule is meant to prevent the unintentional serialization of sensitive information.

Who is the father of JSON? ›

Douglas Crockford is an American computer programmer who is involved in the development of the JavaScript language. He specified the data format JSON (JavaScript Object Notation), and has developed various JavaScript related tools such as the static code analyzer JSLint and minifier JSMin.

How does JSON serialization work? ›

JSON is a format that encodes objects in a string. Serialization means to convert an object into that string, and deserialization is its inverse operation (convert string -> object). If you serialize this result it will generate a text with the structure and the record returned.

What does XML serializer do? ›

XML serialization is the process of converting an object's public properties and fields to a serial format (in this case, XML) for storage or transport. Deserialization re-creates the object in its original state from the XML output.

Which two functions are used for serialization? ›

However, sessions are not the only use of serialization—if you want to implement your own form of persistent objects, the serialize( ) and unserialize( ) functions are a natural choice.

What are Serializers used for? ›

Serializers allow complex data such as querysets and model instances to be converted to native Python datatypes that can then be easily rendered into JSON , XML or other content types.

Why do we need serialization in Django? ›

Django's serialization framework provides a mechanism for “translating” Django models into other formats. Usually these other formats will be text-based and used for sending Django data over a wire, but it's possible for a serializer to handle any format (text-based or not).

When would you use a serializer? ›

Serialization is the process of transforming data into a format that can be stored or transmitted and then reconstructing it. It's used all the time when developing applications or storing data in databases, in memory, or converting it into files.

What is model serializer in Django REST framework? ›

ModelSerializer is a layer of abstraction over the default serializer that allows to quickly create a serializer for a model in Django. Django REST Framework is a wrapper over default Django Framework, basically used to create APIs of various kinds.

What are two popular methods of data serialization? ›

XML , JSON , BSON, YAML , MessagePack, and protobuf are some commonly used data serialization formats.

How does Django serializer get data? ›

How to Serialize Data With DRF
  1. Step 1: Creating Django Application. We'll start by developing a straightforward Django project. ...
  2. Step 2: Creating Our Models. ...
  3. Step 3: Serializing the Data With Django Rest Framework. ...
  4. Step 4: CRUD Methods & View Function. ...
  5. Step 5: Creating the API Endpoints. ...
  6. Step 6: Serializing Nested Data.

What are the disadvantages of serialization? ›

Since serialization does not offer any transaction control mechanisms per se, it is not suitable for use within applications needing concurrent access without making use of additional APIs.

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