I am using apscheduler for my Django project. I am trying to list all users every 10 seconds. But when I try that there is an error:

django.core.exceptions.AppRegistryNotReady: Apps aren't loaded yet.

scheduler.py

from apscheduler.schedulers.background import BackgroundScheduler
from accounts.models import UserProfile

sched = BackgroundScheduler()
def period():
    users = UserProfile.objects.all()
    print(users)
def start():
    sched.add_job(period, 'interval', seconds=10)
    sched.start()

apps.py

from django.apps import AppConfig
from dashboard.scheduler import start

class DashboardConfig(AppConfig):
    default_auto_field = 'django.db.models.BigAutoField'
    name = 'dashboard'
    def ready(self):
        start()

accounts/models.py

from django.contrib.auth.models import AbstractUser
from django.db import models


class UserProfile(AbstractUser):
    username = models.CharField(max_length=500, unique=True)
    first_name = models.CharField(max_length=200)
    last_name = models.CharField(max_length=200)
    password = models.CharField(max_length=250)
    email = models.EmailField(max_length=254)
    isUserActive = models.BooleanField(default=False)

    def __str__(self):
        return self.username

For example, when I do:

def period():
    print("okey!")

It is working. But when I try to get a model objects, it gives an error. How can I solve it?

traceback

Watching for file changes with StatReloader
Exception in thread django-main-thread:
Traceback (most recent call last):
  File "C:\Users\edeni\AppData\Local\Programs\Python\Python39\lib\threading.py", line 973, in _bootstrap_inner
    self.run()
  File "C:\Users\edeni\AppData\Local\Programs\Python\Python39\lib\threading.py", line 910, in run
    self._target(*self._args, **self._kwargs)
  File "C:\Users\edeni\Desktop\project\myvenv\lib\site-packages\django\utils\autoreload.py", line 64, in wrapper
    fn(*args, **kwargs)
  File "C:\Users\edeni\Desktop\project\myvenv\lib\site-packages\django\core\management\commands\runserver.py", line 110, in inner_run
    autoreload.raise_last_exception()
  File "C:\Users\edeni\Desktop\project\myvenv\lib\site-packages\django\utils\autoreload.py", line 87, in raise_last_exception
    raise _exception[1]
  File "C:\Users\edeni\Desktop\project\myvenv\lib\site-packages\django\core\management\__init__.py", line 375, in execute
    autoreload.check_errors(django.setup)()
  File "C:\Users\edeni\Desktop\project\myvenv\lib\site-packages\django\utils\autoreload.py", line 64, in wrapper
    fn(*args, **kwargs)
  File "C:\Users\edeni\Desktop\project\myvenv\lib\site-packages\django\__init__.py", line 24, in setup
    apps.populate(settings.INSTALLED_APPS)
  File "C:\Users\edeni\Desktop\project\myvenv\lib\site-packages\django\apps\registry.py", line 91, in populate
    app_config = AppConfig.create(entry)
  File "C:\Users\edeni\Desktop\project\myvenv\lib\site-packages\django\apps\config.py", line 124, in create
    mod = import_module(mod_path)
  File "C:\Users\edeni\AppData\Local\Programs\Python\Python39\lib\importlib\__init__.py", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1030, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1007, in _find_and_load
  File "<frozen importlib._bootstrap>", line 986, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 680, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 850, in exec_module
  File "<frozen importlib._bootstrap>", line 228, in _call_with_frames_removed
  File "C:\Users\edeni\Desktop\project\dashboard\apps.py", line 2, in <module>
    from dashboard.scheduler import start
  File "C:\Users\edeni\Desktop\project\dashboard\scheduler.py", line 2, in <module>
    from accounts.models import UserProfile
  File "C:\Users\edeni\Desktop\project\accounts\models.py", line 1, in <module>
    from django.contrib.auth.models import AbstractUser
  File "C:\Users\edeni\Desktop\project\myvenv\lib\site-packages\django\contrib\auth\models.py", line 3, in <module>
    from django.contrib.auth.base_user import AbstractBaseUser, BaseUserManager
  File "C:\Users\edeni\Desktop\project\myvenv\lib\site-packages\django\contrib\auth\base_user.py", line 48, in <module>
    class AbstractBaseUser(models.Model):
  File "C:\Users\edeni\Desktop\project\myvenv\lib\site-packages\django\db\models\base.py", line 108, in __new__
    app_config = apps.get_containing_app_config(module)
  File "C:\Users\edeni\Desktop\project\myvenv\lib\site-packages\django\apps\registry.py", line 253, in get_containing_app_config
    self.check_apps_ready()
  File "C:\Users\edeni\Desktop\project\myvenv\lib\site-packages\django\apps\registry.py", line 136, in check_apps_ready
    raise AppRegistryNotReady("Apps aren't loaded yet.")
django.core.exceptions.AppRegistryNotReady: Apps aren't loaded yet.

CodePudding user response：

Import the scheduler module only in the ready function, otherwise you are importhing the serializer, and thus by extent the models before these are loaded:

from django.apps import AppConfig
# no import of the sechduler

class DashboardConfig(AppConfig):
    default_auto_field = 'django.db.models.BigAutoField'
    name = 'dashboard'
    
    def ready(self):
        # import the scheduler in the ready function
        from dashboard.scheduler import start
        start()