Understanding django serializers with examples

Using Serializers,  we can translate Django model objects into other formats like XML, JSON, YAML(YAML Ain’t a Markup Language) with a single command.

from django.core import serializers

data = serializers.serialize("xml", SomeModel.objects.all())

the first argument will be the format we want to serialize the data and second will be a QuerySet to serialize.

we can also translate using a serializer object directly

XMLSerializer = serializers.get_serializer("xml")

xml_serializer = XMLSerializer()

xml_serializer.serialize(queryset)

data = xml_serializer.getvalue()

this is useful when we want data directly be a file like object.

we can also translate only subset of fields using fields argument 

from django.core import serializers

data = serializers.serialize('xml', SomeModel.objects.all(), fields=('name','size')) class Teacher(models.Model):

    name = models.CharField(max_length=50)

    qualification = models.CharField(max_length=50)        

class College(Teacher):

    name = models.models.CharField(max_length=50)

for the inherited models,to translate child class objects we have to list all parent class objects and child class objects into single list,then translate.

all_objects = list(Teacher.objects.all()) + list(College.objects.all())

data = serializers.serialize('xml', all_objects)

Deserializing data:

for obj in serializers.deserialize("xml", data):
    do_something_with(obj)

it will take same arguments as serialize function and returns an iterator

The objects returned by the deserialize iterator are unsavedobjects and Calling DeserializedObject.save() saves the object to the database.

for deserialized_object in serializers.deserialize("xml", data):

    if object_should_be_saved(deserialized_object):

        deserialized_object.save()