Running into a Circular Import issue-CodePudding

I have two apps(front and lrnadmin) in project(portal) this is my root directory

the problem is that when I import the models in each other it gives me error In this models I want Qualification as Foreign key that why I want import Qualification from lrnadmin.models this is my front.models.py

from datetime import datetime, timezone
from django.db import models
from django.db.models import expressions
from django.db.models.base import Model
from django.utils import timezone

from lrnadmin.models import Qualification

class Staff(models.Model):
    """Model definition for Staff."""
    # TODO: Define fields here
    nStaff = models.CharField(max_length= 50)
    role = models.CharField(max_length= 50)
    lrnQ = models.ForeignKey(Qualification, on_delete= models.CASCADE)
    relQ = models.CharField(max_length=200)
    relE = models.CharField(max_length=200)
    # Cv = models.CharField(max_length=100, blank=True, null=True)
    # Doc = models.CharField(max_length=100, blank=True, null=True)
    sec7 = models.ForeignKey(Sec7, on_delete=models.CASCADE)
    class Meta:
        """Meta definition for Staff."""

        verbose_name = 'Staff'
        verbose_name_plural = 'Staffs'

    # def __str__(self):
    #     """Unicode representation of Staff."""
    #     pass

and in this models I want User as Foreign key that why I want import User from front.models this is my lrnadmin.models.py

from django.contrib.auth.models import AbstractUser
from django.db import models
from django.utils import timezone
from front.models import User

class CentreCode(models.Model):
    """Model definition for CentreCode."""

    # TODO: Define fields here
    user = models.ForeignKey(User, on_delete= models.CASCADE)
    centreCode = models.CharField(max_length= 20)
    categories = models.CharField(max_length = 20)
    authorisation = models.CharField(max_length= 20)
    registrationType = models.CharField(max_length= 20)

    class Meta:
        """Meta definition for CentreCode."""

        verbose_name = 'CentreCode'
        verbose_name_plural = 'CentreCodes'

    # def __str__(self):
    #     """Unicode representation of CentreCode."""
    #     pass

How Can I handle this

File "E:\lrn\portal\lrnadmin\models.py", line 4, in <module>
    from front.models import User
  File "E:\lrn\portal\front\models.py", line 7, in <module>
    from lrnadmin.models import Qualification
ImportError: cannot import name 'Qualification' from partially initialized module 'lrnadmin.models' (most likely due to a circular import) (E:\lrn\portal\lrnadmin\models.py)

CodePudding user response：

you can try out the get_model which will avoid importing the model at run time

   from django.apps import apps
   qualification_model = app.get_model('lrnadmin', 'Qualification')

you can try to import the model inside the function instead of importing at module level

CodePudding user response：

You can "lazy-load" a model by using a string literal as described in the docs, so for example with the front app's User model you can define it like:

# Remove from front.models import User


class CentreCode(models.Model):
    # ...
    user = models.ForeignKey('front.User', on_delete= models.CASCADE)
    # ...

Or if you defined front.models.User as a custom user model, it's highly suggested that you just reference the custom model using settings.AUTH_USER_MODEL as described here:

from django.conf import settings
# Remove from front.models import User


class CentreCode(models.Model):
    # ...
    user = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete= models.CASCADE)
    # ...