Python 在ManyToManyField中使用交叉引用时出现Django名称错误

我有一个名为models的包，在这个包中，我有几个单独的python文件中的模型。具体而言，目录结构如下所示：

models/
    __init__.py
    model1.py
    model2.py

models/
    __init__.py
    model1.py
    model2.py

from models import Model1, Model2

在

\uuuu init\uuuuu.py

中：

from model1 import Model1
from model2 import Model2

from django.db import models
from model2 import Model2

class Model1(models.Model):
    field2 = models.ManyToManyFiled(Model2)

from django.db import models
from model1 import Model1

class Model2(models.Model):
    field1 = models.ManyToManyFiled(Model1)

#from model1 import Model1
#from model2 import Model2

from django.db import models

class Model1(models.Model):
    field2 = models.ManyToManyFiled(Model2)
from model2 import Model2

from django.db import models

class Model2(models.Model):
    field1 = models.ManyToManyFiled(Model1)
from model1 import Model1

在

model1.py

中：

from model1 import Model1
from model2 import Model2

from django.db import models
from model2 import Model2

class Model1(models.Model):
    field2 = models.ManyToManyFiled(Model2)

from django.db import models
from model1 import Model1

class Model2(models.Model):
    field1 = models.ManyToManyFiled(Model1)

#from model1 import Model1
#from model2 import Model2

from django.db import models

class Model1(models.Model):
    field2 = models.ManyToManyFiled(Model2)
from model2 import Model2

from django.db import models

class Model2(models.Model):
    field1 = models.ManyToManyFiled(Model1)
from model1 import Model1

在

model2.py

中：

from model1 import Model1
from model2 import Model2

from django.db import models
from model2 import Model2

class Model1(models.Model):
    field2 = models.ManyToManyFiled(Model2)

from django.db import models
from model1 import Model1

class Model2(models.Model):
    field1 = models.ManyToManyFiled(Model1)

#from model1 import Model1
#from model2 import Model2

from django.db import models

class Model1(models.Model):
    field2 = models.ManyToManyFiled(Model2)
from model2 import Model2

from django.db import models

class Model2(models.Model):
    field1 = models.ManyToManyFiled(Model1)
from model1 import Model1

通过将

import

移动到每个文件的末尾，下面的解决方案可以消除NameError，但我无法从其他地方导入模型

在

\uuuu init\uuuuu.py

中：

from model1 import Model1
from model2 import Model2

from django.db import models
from model2 import Model2

class Model1(models.Model):
    field2 = models.ManyToManyFiled(Model2)

from django.db import models
from model1 import Model1

class Model2(models.Model):
    field1 = models.ManyToManyFiled(Model1)

#from model1 import Model1
#from model2 import Model2

from django.db import models

class Model1(models.Model):
    field2 = models.ManyToManyFiled(Model2)
from model2 import Model2

from django.db import models

class Model2(models.Model):
    field1 = models.ManyToManyFiled(Model1)
from model1 import Model1

在

model1.py

中：

from model1 import Model1
from model2 import Model2

from django.db import models
from model2 import Model2

class Model1(models.Model):
    field2 = models.ManyToManyFiled(Model2)

from django.db import models
from model1 import Model1

class Model2(models.Model):
    field1 = models.ManyToManyFiled(Model1)

#from model1 import Model1
#from model2 import Model2

from django.db import models

class Model1(models.Model):
    field2 = models.ManyToManyFiled(Model2)
from model2 import Model2

from django.db import models

class Model2(models.Model):
    field1 = models.ManyToManyFiled(Model1)
from model1 import Model1

在

model2.py

中：

from model1 import Model1
from model2 import Model2

from django.db import models
from model2 import Model2

class Model1(models.Model):
    field2 = models.ManyToManyFiled(Model2)

from django.db import models
from model1 import Model1

class Model2(models.Model):
    field1 = models.ManyToManyFiled(Model1)

#from model1 import Model1
#from model2 import Model2

from django.db import models

class Model1(models.Model):
    field2 = models.ManyToManyFiled(Model2)
from model2 import Model2

from django.db import models

class Model2(models.Model):
    field1 = models.ManyToManyFiled(Model1)
from model1 import Model1

我希望从其他地方使用以下代码导入模型：

models/
    __init__.py
    model1.py
    model2.py

models/
    __init__.py
    model1.py
    model2.py

from models import Model1, Model2

有什么优雅的方法可以解决这个问题吗？

看看。 ManyToManyField必须仅存在于一个模型中，然后在另一个模型中创建一个隐式集，并可以使用后缀_set访问该隐式集。你将有：

class Model1(models.Model):
    field2 = models.ManyToManyField(Model2)

class Model2(models.Model):
    pass  

a = Model1()
b = Model2()
a.field2.add(b)

# Access the sets with:
a.field2.all()
b.model1_set.all()

---

Django准备使用单个模型文件-每个应用程序-是否不可能将Model1和Model2放在models.py文件中？据我所见，pythonI中的循环模块依赖性不好，它还试图将

Model1

和

Model2

放在单个

models.py

中。在这种情况下，

Model1

和

Model2

是交叉引用的，然后在执行

python manage.py syncdb

时，我得到

namererror

（我使用的是django 1.6.x），您必须将类的名称放在引号中，这样django就可以延迟加载it@Alvaro：它很有效，谢谢！但我最终修改了数据库设计，放弃了ManyToManyField，这不是必须的。完全同意。可能需要补充的是，如果同一文件中有循环外键，则可以将模型的名称放在引号中