Return list of objects as dictionary with keys as the objects id with django rest framerwork

I think you can implement the to_representation function in your Serializer.

class MySerializer(serializers.Serializer):    id = serializers.ReadOnlyField()    field1 = serializers.ReadOnlyField()    field2 = serializers.ReadOnlyField()    def to_representation(self, data):        res = super(MySerializer, self).to_representation(data)        return {res['id']: res}        # or you can fetch the id by data directly        # return {str(data.id): res}

You can traverse each item and with a dict comprehension create your desired dictionary. For example:

>>> l = [{ "id": 1, "x": 4}, { "id": 2, "x": 3}]>>> {v["id"]: v for v in l}{1: {'x': 4, 'id': 1}, 2: {'x': 3, 'id': 2}}

EDIT: current version available in a Github project and PYPI (pip install drf-keyed-list)

Here's a general-purpose class that is bi-directional (vs. the read-only implementation above):

class KeyedListSerializer(ListSerializer):    def __init__(self, *args, **kwargs):        super().__init__(*args, **kwargs)        meta = getattr(self.child, 'Meta', None)        assert hasattr(meta, 'keyed_list_serializer_field'), \            "Must provide a field name at keyed_list_serializer_field when using KeyedListSerializer"        self._keyed_field = meta.keyed_list_serializer_field    def to_internal_value(self, data):        # syntax is py3 only        data = [{**v, **{self._keyed_field: k}} for k, v in data.items()]        return super().to_internal_value(data)    def to_representation(self, data):        response = super().to_representation(data)        return {v.pop(self._keyed_field): v for v response}

For Py2, you need to make the super calls explicit and replace the indicated dictionary constructor. You use it by assigning it to your list_serializer_class and selecting a keyed_list_serializer_field (i.e. the field used as the dict key):

class MySerializer(ModelSerializer):    class Meta:        list_serializer_class = KeyedListSerializer        keyed_list_serializer_field = 'id'

The keyed_list_serializer_field should contain unique values; the above implementation doesn't check.