为什么QuesrySet返回TypeError

Question

当我从shell进行迁移/迁移/获取时-除了我的API查询集中：

models.py

class NewsManager(models.Manager):

    def get_queryset(self):
        locale = get_language()
        return super().get_queryset().annotate(title=F('title_' + locale), body=F('body_' + locale),
                                               short_description=F('short_description_' + locale),
                                               seo_title=F('seo_title_' + locale))


class News (models.Model):
    class Meta:
        verbose_name = _('Новини')
        ordering = ("-created_at",)

    title_uk = models.CharField(max_length=255, blank=False)
    title_en = models.CharField(max_length=255, blank=True)
    seo_title_uk = models.CharField(max_length=255, blank=True)
    seo_title_en = models.CharField(max_length=255, blank=True)
    short_description_uk = RichTextField(blank=False)
    short_description_en = RichTextField(blank=True)
    body_uk = RichTextField(blank=False)
    body_en = RichTextField(blank=True)
    created_at = models.DateTimeField(auto_now_add=True)
    published = models.BooleanField(default=False)

    objects = NewsManager()

api / views.py

class NewsAPIView(generics.ListAPIView):
    """
    list:
    Return a list of all news
    """
    serializer_class = NewsPreviewSerializer

    def get_queryset(self):
        return News.objects.all().exclude(published=False)


class NewsDetailAPIView(generics.RetrieveAPIView):
    """
    get:
    Return one News obj by id
    """
    serializer_class = NewsSerializer
    queryset = News.objects.all()
    lookup_field = 'id'


TypeError: must be str, not NoneType
return super().get_queryset().annotate(title=F('title_' + locale), body=F('body_' + locale),