我有一个非常简单的方法：
Class Team(models.Model):
def sides(self):
return SideNames.objects.filter(team=self)
SideNames 是与 Team 在同一文件中定义的另一个模型，
当我尝试测试时：
self.assertEquals(len(t.sides()), 2)
我收到以下错误：
return SideNames.objects.filter(team=self)AttributeError：“NoneType”对象没有属性“对象”
但是如果我将测试更改为
self.assertEquals(len(SideNames.objects.filter(team=t)), 2)
然后我没有得到错误。从测试本身调用 SideNames.objects.filter 和调用实际方法有什么区别？
作为参考，这里是完整的 2 个类。
class Team(models.Model):
"""The model for a football team."""
class Admin:
pass
def __unicode__(self):
return u'%s' % self.name
def is_player(self, player):
"""Checks to see if 'player' is a member if this team. Returns True if they are, or False otherwise."""
try:
teamPlayer = TeamPlayers.objects.get(player=player, team=self)
return True
except ObjectDoesNotExist:
return False
def sides(self):
"""Return the side names for this team"""
return SideNames.objects.filter(team=self)
def updateSides(self, side_a, side_b):
"""Update the side names"""
names = SideNames.objects.filter(team=self);
a = SideNames.objects.get(name = names[0].name)
a.name = side_a
a.save()
b = SideNames.objects.get(name = names[1].name)
b.name = side_b
b.save()
name = models.CharField("Team Name", max_length=255)
organiser = models.ForeignKey(User)
class SideNames(models.Model):
"""Holds the names of the sides for each team"""
class Admin:
pass
def __unicode__(self):
"""Pretty print the SideNames object"""
return self.name
team = models.ForeignKey(Team)
name = models.CharField(max_length=128)