serializer.Serializer's context gets lost on adding field to it

[zamoosh]

When I want to add my custom prop to instance of serializer.Serializer class in some validate_some_field, the context property gets {} !

Simply try this peace of code:

In some random serializer.Serializer:

class WritePictureSerializerAdmin(serializers.Serializer):
    name = serializers.CharField(trim_whitespace=True)

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)

        setattr(self, "level", 0)
        setattr(self, "parent", None)

    def to_representation(self, instance):
        ret = {"msg": ""}
        # ❌ here I'll get error, because self.context has no key inside it
        match self.context["view"].action:
            case "create":
                ret["msg"] = "some create msg"
            case "update" | "partial_update":
                ret["msg"] = "some update msg"
        return ret

    def update(self, instance, validated_data):
        try:
            instance.name = validated_data["name"]
            instance.save()
            return instance
        except Exception as e:
            raise CustomExceptionOnlyMsg(str(e), status.HTTP_424_FAILED_DEPENDENCY)

    def validate_name(self, value):
        # 👉 self.context contains data
        self.some_prop = None
        # 👉 self.context is {}
        return value

[zamoosh]

If I use self._context in match ... case statement, this would be fine.
But at least why self.context gets {} on setting value to self?