Abstract django model serializer. Instead of flat structure, allows using hierarchies. You must override Model in descendants. Constructor works in two ways: 1. Passing only model instance - serializes it to dict (self.data); 2. Passing both instance and data - in that order - deserializes data into passed instance. See attached usage.py for exa…

serializer.py

import os
from django.db import models


class SimpleSerializer(object):
    Model = None
    exclude = ()
    ingored_fields = (
        models.AutoField,
        models.ForeignKey,
        models.fields.related.RelatedField,
    )

    def __init__(self, instance_or_dict, instance=None):
        if instance is None:
            self.serialize(instance_or_dict)
        else:
            self.deserialize(instance_or_dict, instance)

    def serialize(self, instance):
        exclude = set(self.exclude)
        self.data = {}
        for field in self.Model._meta.fields:
            if field.name in exclude:
                continue
            if isinstance(field, self.ingored_fields):
                continue
            if field.primary_key:
                continue
            self.data[field.name] = getattr(instance, field.name)

    def deserialize(self, data, instance):
        field_names = set([field.name for field in self.Model._meta.fields])
        field_names.difference_update(set(self.exclude))
        for key in data:
            if key in field_names:
                setattr(instance, key, data[key])

usage.py

from course.models import Course
from core.serializers import SimpleSerializer
from exercise.serializers import BlockSerializer


class CourseSerializer(SimpleSerializer):
    Model = Course
    exclude = ('blocks',)

    def serialize(self, instance):
        super(CourseSerializer, self).serialize(instance)
        self.data['blocks'] = self.serialize_blocks(instance)

    def serialize_blocks(self, instance):
        for block in instance.blocks.all():
            yield BlockSerializer(block).data

    def deserialize(self, data, instance):
        super(CourseSerializer, self).deserialize(data, instance)
        for block_data in data['blocks']:
            block = Block(org=instance.org)
            BlockSerializer(block_data, block)
            instance.append_block(block)