可以从视图返回``响应''，`httpresponse'或`httpStreamingResponse`，但收到了一个'＆lt; class＆＃x27; noneType＆gt;

Question

我正在收到错误

期望响应，httpresponse或httpstreamingresponse be 从视图返回，但收到了＆lt;类'nontype'＆gt; 在django drf中，

在我的查询中，我试图将所有相关项目的数量计算到一个特定项目

the views.py

@api_view(['GET'])
def getVesselInfo(request):
    vessels = (Vessel.objects.annotate(
        Count('vessel_components', distinct=True)))
    vSerializer = VesselSerializer(vessels, many=True)
    return Response(vSerializer.data,)

models.py.py：

class Vessel(models.Model):
    name = models.CharField(max_length=255)
    imo = models.CharField(max_length=255)

    def __str__(self):
        return self.name

class Component(MP_Node):
    name = models.CharField(max_length=255, blank=True, null=True)
    manufacturer = models.CharField(max_length=200, blank=True, null=True)
    model = models.CharField(max_length=200, blank=True, null=True)
    type = models.CharField(max_length=200, blank=True, null=True)
    remarks = models.TextField(blank=True, null=True)
    vessel = models.ForeignKey(
        Vessel, blank=True, null=True, on_delete=models.CASCADE, related_name='vessel_components')

    def __str__(self):
        return self.name