1
我有一个名为Team
的课程,有胜利和失败。
我希望能够通过win_pct
排序球队,这应该是胜率与总比赛的比率(即wins.count()/(wins.count() + losses.count())
)。如何通过派生计算对对象进行排序?
class Team(TimestampModerated):
name = models.CharField(max_length=80, blank=False, null=False)
wins = models.ManyToManyField('self', blank=True, symmetrical=False, related_name='related_wins')
losses = models.ManyToManyField('self', blank=True, symmetrical=False, related_name='related_losses')
def num_wins(self):
return self.wins.count()
def num_losses(self):
return self.losses.count()
def win_pct(self):
return self.wins.count()/(self.wins.count() + self.losses.count())
所以,在我看来,我有这样的事情:
@list_route
def teams_list(self, request):
teams = Team.objects.all().order_by('-win_pct')
page = self.paginate_queryset(teams)
if page is not None:
serializer = self.get_serializer(page, many=True)
return self.get_paginated_response(serializer.data)
serializer = self.get_serializer(teams, many=True)
return Response(
data=serializer.data
)
,但它只是给出了一个错误:
django.core.exceptions.FieldError: Cannot resolve keyword 'win_pct' into a field. Choices are: created, id, losses, moderation_code, related_losses, related_wins, name, updated, wins