Python 异常值:类型对象';纪律';没有属性';说明';
因此,我正在使用Django Rest框架构建我的第一个Django项目,我有以下3个模型:Python 异常值:类型对象';纪律';没有属性';说明';,python,django,django-rest-framework,django-1.8,Python,Django,Django Rest Framework,Django 1.8,因此,我正在使用Django Rest框架构建我的第一个Django项目,我有以下3个模型: class Student(models.Model): user = models.OneToOneField(User, unique=True) ra = models.IntegerField() class Discipline (models.Model): description = models.CharField(max_length=150) pro
class Student(models.Model):
user = models.OneToOneField(User, unique=True)
ra = models.IntegerField()
class Discipline (models.Model):
description = models.CharField(max_length=150)
professor = models.ForeignKey(Professor, related_name='disciplines')
learners = models.ManyToManyField('students.Student', through='enrollments.enrollment', related_name='disciplines')
class Enrollment (models.Model):
discipline = models.ForeignKey('disciplines.Discipline')
student = models.ForeignKey(Student)
enroll_date = models.DateField(auto_now_add=True)
对于这些模型,我有以下序列化程序:
class StudentSerializer (serializers.ModelSerializer):
ra = serializers.IntegerField(source=Student.ra)
disciplines = EnrolledDisciplinesSerializer(source="enrollment_set", many=True)
activities = RealizedActivitiesSerializer(source='activities_set', many=True)
class Meta:
model = User
fields = ('id','username', 'email', 'password', 'ra', 'disciplines','activities')
class DisciplineSerializer (serializers.ModelSerializer):
professor = serializers.StringRelatedField()
learners = LearnersSerializer(source="enrollment_set", many=True)
class Meta:
model = Discipline
fields = ('id', 'description', 'professor', 'learners')
class EnrolledDisciplinesSerializer(serializers.ModelSerializer):
id = serializers.ReadOnlyField(source=Discipline.pk)
description = serializers.ReadOnlyField(source=Discipline.description)
class Meta:
model = Enrollment
fields = ('id', 'description', 'enroll_date')
class LearnersSerializer(serializers.ModelSerializer):
id = serializers.ReadOnlyField(source=Student.pk)
ra = serializers.ReadOnlyField(source=Student.ra)
class Meta:
model = Enrollment
fields = ('id', 'ra', 'enroll_date')
在my views.py for my students应用程序中,我有以下代码:
class StudentList (generics.ListCreateAPIView):
model = Student
serializer_class = StudentSerializer
permission_classes = [
permissions.IsAuthenticatedOrReadOnly,
]
class StudentDetail (generics.RetrieveAPIView):
model = Student
serializer_class = StudentSerializer
class StudentDisciplineList (generics.ListAPIView):
model = Enrollment
serializer_class = EnrolledDisciplinesSerializer
def get_queryset(self):
queryset = super(StudentDisciplineList, self).get_queryset()
return queryset.filter(student__pk=self.kwargs.get('pk'))
class StudentActivitiesList (generics.ListAPIView):
model = Activity
serializer_class = ActivitiesSerializer
def get_queryset(self):
queryset = super(StudentActivitiesList, self).get_queryset()
return queryset.filter(student__pk=self.kwargs.get('pk'))
创建视图后,我将以下内容添加到我的学生应用程序中的url.py文件中:
url_patterns = [
'',
url(r'^/(?P<pk>\d+)/disciplines$', StudentDisciplineList.as_view(), name='studentdiscipline-list'),
url(r'^/(?P<pk>\d+)/activities$', StudentActivitiesList.as_view(), name='studentactivities-list'),
url(r'^/(?P<pk>\d+)$', StudentDetail.as_view(), name='student-detail'),
url(r'^$', StudentList.as_view(), name='student-list'),
]
完成此操作后,我转到并获得以下信息:
File "C:\Users\Douglas\tg_project\enrollments\serializers.py" in EnrolledDisciplinesSerializer
9. description = serializers.ReadOnlyField(source=Discipline.description)
Exception Type: AttributeError at /admin
Exception Value: type object 'Discipline' has no attribute 'description'
我已经在Google和StackOverflow上搜索过了,但是我找不到任何帮助我的东西。我还查看了整个代码,看看是否有任何打字错误,但似乎一切都正常
我非常感谢您为解决此问题提供的帮助。源代码应该是一个字符串,其中包含要从
注册
实例获取的属性。因此,在您的注册DisciplinedSerializer
中,对于说明
,您需要“规程.说明”
<代码>规程(小写)是访问该注册规程的属性名称,说明
是获取该规程实例说明的名称。其他字段也一样
Django使用元类构造模型。按照这种方式,您在模型中定义的字段最终不会作为类的属性。这意味着
规程
类将没有属性规程.description
。只有规程
的实例具有说明
属性 为什么disciply=models.ForeignKey('disciplies.disciply')
在注册
模型中,而不仅仅是disciply=models.ForeignKey(学科)
?@Pynchia每当我尝试执行此操作时,在f.rel.through.\u meta.local\u字段中,我都会收到m2m的以下错误:AttributeError:'str'对象没有属性'\u meta'
File "C:\Users\Douglas\tg_project\enrollments\serializers.py" in EnrolledDisciplinesSerializer
9. description = serializers.ReadOnlyField(source=Discipline.description)
Exception Type: AttributeError at /admin
Exception Value: type object 'Discipline' has no attribute 'description'