动态修改字段：
序列化程序初始化后，可以使用. fields属性访问在序列化程序上设置的字段字典。访问和修改此属性允许动态修改序列化程序。
直接修改fields参数允许您执行一些有趣的操作，例如在运行时而不是在声明序列化程序时更改序列化程序字段的参数。
遵循上述文档中的示例：
serializers.py

class DynamicFieldsModelSerializer(serializers.ModelSerializer):
    """
    A ModelSerializer that takes an additional `fields` argument that
    controls which fields should be displayed.
    """

    def __init__(self, *args, **kwargs):
        # Don't pass the 'fields' arg up to the superclass
        fields = kwargs.pop('fields', None)

        # Instantiate the superclass normally
        super().__init__(*args, **kwargs)

        if fields is not None:
            # Drop any fields that are not specified in the `fields` argument.
            allowed = set(fields)
            existing = set(self.fields)
            for field_name in existing - allowed:
                self.fields.pop(field_name)

class TaskSerializer(DynamicFieldsModelSerializer):
    class Meta:
        fields = (
            "id",
            "title",
            "body",
            "author",
            "deadline",
            "done",
        )
        model = Task

在views.py上，您可以覆盖ListCreateAPIView提供的get或ListModelMixin提供的list方法，如本示例和以下代码块所示：
views.py

class TaskList(generics.ListCreateAPIView):
    # permission_classes = (IsAuthorOrReadOnly,)
    queryset = Task.objects.all()
    serializer_class = TaskSerializer

    def list(self, request):
        # Note the use of `get_queryset()` instead of `self.queryset`
        queryset = self.get_queryset()
        serializer = TaskSerializer(queryset, many=True, fields=('id', 'title', 'deadline'))
        return Response(serializer.data)

        
class TaskDetail(generics.RetrieveUpdateDestroyAPIView):
    # permission_classes = (IsAuthorOrReadOnly,)
    queryset = Task.objects.all()
    serializer_class = TaskSerializer