put请求（单整体改），patch请求（群单改，群改）

# Bookv2ModelSerializer(instance=修改的对象, data=request_data,partial=默认False)
    def put(self, request, *args, **kwargs):
        request_data = request.data
        pk = kwargs.get(‘pk‘)
        old_book_obj = models.Book.objects.filter(pk=pk).first()  # 获取obj
        # 目的：将众多数据的校验交给序列化来处理，让序列化类进行反序列化操作，校验成功后入库
        # data传入数据是进行校验，并且才能走.is_valid(raise_exception=True)校验是否成功
        # instance如若有值,save走的是update操作，进行修改操作
        book_ser = serializers.Bookv2ModelSerializer(instance=old_book_obj, data=request_data)
        book_ser.is_valid(raise_exception=True)  # raise_exception=True如果问题抛出异常
        book_ser.save()
        return Response({
            ‘status‘: 0,
            ‘msg‘: ‘修改成功‘,
            "results": book_ser.data
        })

# Bookv2ModelSerializer(instance=old_book_obj, data=request_data,partial=True)
    def patch(self, request, *args, **kwargs):
        request_data = request.data
        pk = kwargs.get(‘pk‘)
        old_book_obj = models.Book.objects.filter(pk=pk).first()
        # partial=True
        book_ser = serializers.Bookv2ModelSerializer(instance=old_book_obj, data=request_data,partial=True)
        book_ser.is_valid(raise_exception=True)
        book_ser.save()
        return Response({
            ‘status‘: 0,
            ‘msg‘: ‘修改成功‘,
            "results":serializers.Bookv2ModelSerializer(old_book_obj).data
        })
   

def patch(self, request, *args, **kwargs):
        request_data = request.data
        pk = kwargs.get(‘pk‘)
        if pk and isinstance(request_data, dict):  # 单改
            pks = [pk, ]
            request_data = [request_data, ]
        elif isinstance(request_data, list):  # 群改
            pks = []
            for dic in request_data:
                # 字典是可变类型，在弹出的时候，原生的字典也会改变，dic的指向依然是request_data内存地址，dic变，它也变
                pk = dic.pop(‘pk‘, None)
                if pk:
                    pks.append(pk)  # 把pk值弹出来，加入pks
                else:
                    return Response({
                        ‘status‘: 2,
                        ‘msg‘: ‘数据有误‘,
                    })
        else:
            return Response({
                ‘status‘: 1,
                ‘msg‘: ‘数据有误‘,
            })

        # pks与request_data数据筛选
        # 1.将pks中的没有对应数据的pk与数据已删除的数据pk移除，request_data索引对应的数据也移除
        # 2.将合理的pks转换为对象
        obj_list = []
        new_request_data = []
        for index, pk in enumerate(pks):
            try:
                # pk对应的数据合理，将合理的对象存储,并把删除的数据过滤掉
                obj = models.Book.objects.get(pk=pk，is_delete=False)
                obj_list.append(obj)
                # 对应索引的数据就需要保存下来
                new_request_data.append(request_data[index])
            except:
                # pk对应的数据有误，将对应索引的data从request_data中移除
                # request_data.pop(index)
                continue
        book_ser = serializers.Bookv2ModelSerializer(instance=obj_list, data=new_request_data, partial=True, many=True)
        book_ser.is_valid(raise_exception=True)
        book_objs = book_ser.save()
        return Response({
            ‘status‘: 0,
            ‘msg‘: ‘修改成功‘,
            "results": serializers.Bookv2ModelSerializer(book_objs, many=True).data
        })

class Bookv2ListSerializer(ListSerializer):
    def update(self, instance, validated_data):
        print(instance)  # book对应各个对象
        print(validated_data)  # 修改的数据
        print(self.child)  # 服务模型序列化的类
        for index, obj in enumerate(instance):
            self.child.update(obj, validated_data[index])
        return instance

class Bookv2ModelSerializer(ModelSerializer):
    # publishs = PublishModelSerializer()
    class Meta:
        model = models.Book
        fields = (‘name‘, ‘price‘, ‘img‘, ‘publish_name‘, ‘author_list‘, ‘publish‘, ‘authors‘)

        # 群改，需要设置 自定义ListSerializer，重写update方法
        list_serializer_class = Bookv2ListSerializer