django rest_framework 錯誤信息 AssertionError: When a serializer is passed a `data` keyword

今天在學習django 的rest_framework規範時，遇到了 AssertionError: When a serializer is passed a `data` keyword argument you must call `.is_valid()` before attempting to access the serialized `.data` representation. 錯誤信息。記錄一下解決方法。

錯誤代碼：

class BookModelSerializer(serializers.ModelSerializer):
    class Meta:
        model = Books
        fields = "__all__"


class BooksView(APIView):
    def get(self, request):
        book_list = Books.objects.all()
        ret = BookModelSerializer(book_list, many=True)
        return Response(ret.data)

    def post(self, request):
        print(request.data)
        bs = BookModelSerializer(data=request.data)
        print(bs.data)
        if bs.is_valid():
            return Response(bs.data)

        else:
            return Response(bs.errors)

錯誤原因：

首先在將序列化的數據反序列化成對象時，要在序列化類的參數中指明data=序列化的數據

在調用對象.data時，要先執行.is_valid()方法後，才能調用

所以修改成下面這樣就不報錯了

class BookModelSerializer(serializers.ModelSerializer):
    class Meta:
        model = Books
        fields = "__all__"


class BooksView(APIView):
    def get(self, request):
        book_list = Books.objects.all()
        ret = BookModelSerializer(book_list, many=True)
        return Response(ret.data)

    def post(self, request):
        print(request.data)
        bs = BookModelSerializer(data=request.data)
        if bs.is_valid():
            print(bs.data)
            return Response(bs.data)

        else:
            return Response(bs.errors)