DRF ManyToMany Field 在创建对象时出现错误

我有一个Rant模型与Category使用链接到它ManyToManyField。我已经序列化了它，但问题是这个错误：

{
  "categories": [
    "Expected a list of items but got type \"str\"."
  ]
}

这些是我的序列化器：

class CategorySerializer(serializers.ModelSerializer):
    class Meta:
        model = Category
        fields = "__all__"


class RantSerializer(serializers.ModelSerializer):
    categories = CategorySerializer(many=True)


    class Meta:
        model = Rant
        fields = ('rant', 'slug', 'categories')

My post方法是这样的：

    def post(self, request, format=None):
        serializer = RantSerializer(data=request.data)
        if serializer.is_valid():
            serializer.save()
            return Response(serializer.data, status=status.HTTP_201_CREATED)
        return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)

我在这里做错了什么？

我也遇到过类似的问题。请执行以下操作来解决您的问题

1. 安装 drf-writable-nestedpip install drf-writable-nested
2. 像这样重写你的序列化器

# --- snip ---
from drf_writable_nested.serializers import WritableNestedModelSerializer

class CategorySerializer(serializers.ModelSerializer):
    class Meta:
        model = Category
        fields = "__all__"


class RantSerializer(WritableNestedModelSerializer):
    categories = CategorySerializer(many=True)


    class Meta:
        model = Rant
        fields = ('rant', 'slug', 'categories')
# ---snip ----

这里的问题是导入并实现WritableNestedModelSerializer班级。另请注意，serializers.ModelSerializer您想要执行嵌套有效负载的序列化器上的超类已被替换。

3. 尝试执行 API 调用。你应该可以走了。

有关更多信息，请参阅此存储库的自述文件here https://github.com/beda-software/drf-writable-nested