python - TypeError: manager_method() argument after ** must be a mapping, not str

Question

Sorry, I am new to django rest framework and am having some trouble.

I am using a nested serializer that I would like to add a create() method for.

In trying to do so: I have created the following serializers.py:

class ASerializer(serializers.ModelSerializer):
    class Meta:
        model = A
        fields = (
            "id",
            "name",
        )


class BSerializer(serializers.ModelSerializer):
    class Meta:
        model = B
        fields = (
            "id",
            "name",
        )


class CSerializer(serializers.ModelSerializer):
    class Meta:
        model = C
        fields = (
            "id",
            "name",
        )

class NSerializer(serializers.ModelSerializer):
    a = ASerializer()
    b = BSerializer()
    c = CSerializer()

    class Meta:
        model = N
        fields = (
            "id",          
            "a",
            "b",               
            "c",
            "description",
        )

    def create(self, validated_data):
        a_data= validated_data.pop("a")
        b_data= validated_data.pop("b")
        c_data= validated_data.pop("c")
        n = N.objects.create(**validated_data)

        for one in a.data:
            A.objects.create(n=n, **one)

        for two in b.data:
            B.objects.create(n=n, **two)

        for three in c.data:
            C.objects.create(n=n, **three)

        return n

I want to be able to perform a POST on the data in the following format:

{
    "id": 1,
    "a": {
        "id": 1,
        "name": "apple"
    },
    "b": {
        "id": 5,
        "name": "red"
    },
    "c": {
        "id": 2,
        "name": "medium"
    },
    "description": "a description."
}

My models are linked via foreign keys and I can perform requests just fine without the create() in my django admin endpoint (would post my models.py here but the code is already rather large for a question) but I am wondering why I am getting the following error:

TypeError: django.db.models.manager.BaseManager._get_queryset_methods.<locals>.create_method.<locals>.manager_method() argument after ** must be a mapping, not str

It makes sense that my admin would work fine given that it has no jurisdiction over my serializers from what I understand. I believe this means the error lies here in my serializers.py. Any help would be greatly appreciated, thank you so much!

Answer 1

等待大神解答