Import app model class in another app model - django

Question

I got 2 app: coworkers and services, each one with its own models.py
In coworkers models.py, I can "from services.models import Services".
When I try to "from coworkers.models import Status" in services models.py, I get this error message:
Traceback (most recent call last): File
"/Users/lucas/Documents/projetos/cwk-manager/lib/python2.7/site-packages/Django-1.4.3-py2.7.egg/django/core/management/commands/runserver.py",
line 91, in inner_run
self.validate(display_num_errors=True) File "/Users/lucas/Documents/projetos/cwk-manager/lib/python2.7/site-packages/Django-1.4.3-py2.7.egg/django/core/management/base.py",
line 266, in validate
num_errors = get_validation_errors(s, app) File "/Users/lucas/Documents/projetos/cwk-manager/lib/python2.7/site-packages/Django-1.4.3-py2.7.egg/django/core/management/validation.py",
line 30, in get_validation_errors
for (app_name, error) in get_app_errors().items(): File "/Users/lucas/Documents/projetos/cwk-manager/lib/python2.7/site-packages/Django-1.4.3-py2.7.egg/django/db/models/loading.py", line 158, in get_app_errors
self._populate() File "/Users/lucas/Documents/projetos/cwk-manager/lib/python2.7/site-packages/Django-1.4.3-py2.7.egg/django/db/models/loading.py", line 64, in _populate
self.load_app(app_name, True) File "/Users/lucas/Documents/projetos/cwk-manager/lib/python2.7/site-packages/Django-1.4.3-py2.7.egg/django/db/models/loading.py", line 88, in load_app
models = import_module('.models', app_name) File "/Users/lucas/Documents/projetos/cwk-manager/lib/python2.7/site-packages/Django-1.4.3-py2.7.egg/django/utils/importlib.py",
line 35, in import_module
import(name) File "/Users/lucas/Documents/projetos/cwk-manager/cwk-manager/cwk_manager/coworkers/models.py",
line 2, in
from services.models import Services File "/Users/lucas/Documents/projetos/cwk-manager/cwk-manager/cwk_manager/services/models.py",
line 5, in
class Services(models.Model): File "/Users/lucas/Documents/projetos/cwk-manager/cwk-manager/cwk_manager/services/models.py",
line 11, in Services
status = models.ForeignKey(Status) NameError: name 'Status' is not defined
--
coworker models.py
from django.db import models
from services.models import Services
class Status(models.Model):
status_name = models.CharField(max_length=50)
status_description = models.TextField(blank=True, null=True)
class Meta:
verbose_name = "Status"
verbose_name_plural = "Status"
def __unicode__(self):
return self.status_name
services models.py
from django.db import models
from coworkers.models import Status
# This table contains all the information about plans and other general services provided.
class Services(models.Model):
service_name = models.CharField(max_length=100)
service_description = models.TextField(blank=True, null=True)
service_price = models.DecimalField(max_digits=7, decimal_places=2, blank=True, null=True)
creation_date = models.DateField(auto_now_add=True)
last_update = models.DateField(auto_now=True)
status = models.ForeignKey(Status)
class Meta:
verbose_name = "Services"
verbose_name_plural = "Services"
def __unicode__(self):
return self.service_name
--
Can someone help me to see what I am doing wrong?
Thanks in advance!

Answer 1

This is caused by circular import in Python.
You can use this syntax:
status = models.ForeignKey('coworkers.models.Status')
Django will determine model using this path so you don't need to import Status.
Another solution in your case would be to delete 2nd import statement in coworker.models because Services doesn't seem to be used in this file.

Answer 2

In Django 1.6.5 this:
import coworkers
status = models.ForeignKey(coworkers.models.Status)
Should be this:
import coworkers
status = models.ForeignKey(coworkers.Status)
I am (now) aware the the OP is using Django 1.4.3 and that some of the answers may solve this in that version of Django. However, it took me a while to notice the version and those answers do not work in 1.6.5.
Cheers!

Answer 3

It's circularly import, which results errors.
You can try,
import coworkers
status = models.ForeignKey(coworkers.models.Status)

Answer 4

Just create the Status model first and do syncdb and after that create the services model and syncdb. It should work.
The problem is that python is not ab le to find the 'Status' coz its first trying to create the Services model.

Answer 5

I got all sorts of errors like this while doing syncdb:
CommandError: One or more models did not validate: parts.vehicle:
'customer' has a relation with model <class
'customers.models.Customer'>, which has either not been installed or
is abstract.
I finally realized I had forgotten to add the new app to settings.py. Admin couldn't find it either. That should have been my first clue. Otherwise I was doing what was in the answer by e.thompsy for django 1.6.5