[Answer]-Django serialization get foreign key object with primary key object

This can be achieved by providing both person and author objects to serializers.

In [39]: from person.models import *

In [40]: from django.core import serializers

In [41]: query_obj = Author.objects.get(person__first_name = 'Dheerendra')

In [42]: ser_json = serializers.serialize('json', [query_obj, query_obj.person])

In [43]: ser_json
Out[43]: '[{"pk": 1, "model": "person.author", "fields": {"reg_num": "CZG29742XD4", "person": 1}}, {"pk": 1, "model": "person.person", "fields": {"first_name": "Dheerendra", "last_name": "Rathor"}}]'

In [45]: from ast import literal_eval 

In [46]: ser_json = literal_eval(ser_json)

In [47]: ser_json[0]['fields']["person"] = ser_json[1]

In [48]: [ser_json[0]]
Out[48]: 
[
  {   
        'fields':   
        {
            'reg_num': 'CZG29742XD4',
            'person': 
            {
              'fields': 
                    {
                          'first_name': 'Dheerendra',
                          'last_name': 'Rathor'
                    },
                    'model': 'person.person',
                    'pk': 1
           }
      }
  'model': 'person.author',
  'pk': 1
  }
]

You can convert it back to json object using simplejson library.

In [1]: import simplejson

In [2]: ser_json = simplejson.dumps([ser_json[0]])

Use python module json

Json documentation

Write a function that returns the required json.

Django doesn’t support this in-depth serialization

https://code.djangoproject.com/ticket/4656

You can use django rest framework or tastypie to do that. Both are well capable to do that.