Django 1.9 django.core.exceptions.AppRegistryNotReady: Apps aren't loaded yet

Question

Trying to use django-shopify-sync in a Django 1.9 project. When loading the config for the app it gives me the following error, likely because it's trying to load some models in the config?

Tried moving the the two imports that eventually import models into the ready() function below, but still getting the same error. Culpirt lines 2 and 3 in the following file https://github.com/andresdouglas/django-shopify-sync/blob/master/shopify_sync/apps.py

The error is:

    $ python manage.py runserver
Unhandled exception in thread started by <function wrapper at 0x10753e500>
Traceback (most recent call last):
  File "/Users/andres/.virtualenvs/[...]/lib/python2.7/site-packages/django/utils/autoreload.py", line 226, in wrapper
    fn(*args, **kwargs)
  File "/Users/andres/.virtualenvs/[...]/lib/python2.7/site-packages/django/core/management/commands/runserver.py", line 109, in inner_run
    autoreload.raise_last_exception()
  File "/Users/andres/.virtualenvs/[...]/lib/python2.7/site-packages/django/utils/autoreload.py", line 249, in raise_last_exception
    six.reraise(*_exception)
  File "/Users/andres/.virtualenvs/[...]/lib/python2.7/site-packages/django/utils/autoreload.py", line 226, in wrapper
    fn(*args, **kwargs)
  File "/Users/andres/.virtualenvs/[...]/lib/python2.7/site-packages/django/__init__.py", line 18, in setup
    apps.populate(settings.INSTALLED_APPS)
  File "/Users/andres/.virtualenvs/[...]/lib/python2.7/site-packages/django/apps/registry.py", line 85, in populate
    app_config = AppConfig.create(entry)
  File "/Users/andres/.virtualenvs/[...]/lib/python2.7/site-packages/django/apps/config.py", line 116, in create
    mod = import_module(mod_path)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/importlib/__init__.py", line 37, in import_module
    __import__(name)
  File "/Users/andres/.virtualenvs/[...]/src/shopify-sync/shopify_sync/apps.py", line 2, in <module>
    from shopify_sync.handlers import webhook_received_handler
  File "/Users/andres/.virtualenvs/[...]/src/shopify-sync/shopify_sync/handlers.py", line 3, in <module>
    from .models import (CustomCollection, Customer, Order, Product, Shop,
  File "/Users/andres/.virtualenvs/[...]/src/shopify-sync/shopify_sync/models/__init__.py", line 3, in <module>
    from .address import Address
  File "/Users/andres/.virtualenvs/[...]/src/shopify-sync/shopify_sync/models/address.py", line 6, in <module>
    from .base import ShopifyResourceModel
  File "/Users/andres/.virtualenvs/[...]/src/shopify-sync/shopify_sync/models/base.py", line 144, in <module>
    class ShopifyResourceModel(models.Model):
  File "/Users/andres/.virtualenvs/[...]/lib/python2.7/site-packages/django/db/models/base.py", line 94, in __new__
    app_config = apps.get_containing_app_config(module)
  File "/Users/andres/.virtualenvs/[...]/lib/python2.7/site-packages/django/apps/registry.py", line 239, in get_containing_app_config
    self.check_apps_ready()
  File "/Users/andres/.virtualenvs/[...]/lib/python2.7/site-packages/django/apps/registry.py", line 124, in check_apps_ready
    raise AppRegistryNotReady("Apps aren't loaded yet.")
django.core.exceptions.AppRegistryNotReady: Apps aren't loaded yet.

UPDATE: If I move the following lines (model imports) https://github.com/andresdouglas/django-shopify-sync/blob/master/shopify_sync/handlers.py#L3-L4 to inside get_topic_models it seems to fix the error. But that's kind of dirty, can anyone come up with a better solution?

That certainly looks like the culprit, but not guilty until proven. Are you seeing this error when you do ./manage.py runserver or with something else — e4c5, May 11 '16 at 07:03
you have registered shopify-sync as an app in INSTALLED_APPS ? — e4c5, May 11 '16 at 07:06

John Percival Hackworth · Answer 1 · 2016-05-12T00:47:52.253

It looks like you may have an ordering issue. Make sure your application is in the INSTALLED_APPS tuple after django-shopify-sync. You can find a few more details in the Application registry documentation.

As unsatisfying as an inline import is, you may be stuck with it. I'd suggest moving

from shopify_sync.handlers import webhook_received_handler
from shopify_webhook.signals import webhook_received

into the ready method in apps.py. This will delay the import until the models are ready.

The change I tried is:

diff --git a/shopify_sync/apps.py b/shopify_sync/apps.py
index 663b43b..0bc1fcc 100644
--- a/shopify_sync/apps.py
+++ b/shopify_sync/apps.py
@@ -1,7 +1,5 @@
 from django.apps import AppConfig
-from shopify_sync.handlers import webhook_received_handler
-from shopify_webhook.signals import webhook_received
-
+import importlib

 class ShopifySyncConfig(AppConfig):
     """
@@ -16,5 +14,9 @@ class ShopifySyncConfig(AppConfig):
         The ready() method is called after Django setup.
         """

+        signals_webhook_received = importlib.import_module('.signals', package='shopify_webhook')
+        handlers_webhook_received_handler = importlib.import_module('.handlers', package='shopify_sync')
+
         # Connect shopify_webhook's webhook_received signal to our synchronisation handler.
-        webhook_received.connect(webhook_received_handler, dispatch_uid = 'shopify_sync_webhook_received_handler')
+        signals_webhook_received.webhook_received.connect(handlers_webhook_received_handler.webhook_received_handler, dispatch_uid = 'shopify_sync_webhook_received_handler')
+

django-shopify-sync is the application I'm trying to add. Which other application are you referring to? — Andres, May 11 '16 at 23:25
My bad, I misunderstood your question. Lemme look a bit closer. — John Percival Hackworth, May 11 '16 at 23:28
Thanks for the suggestion. I believe that doesn't actually work, because that get called before the app is ready. You have to move the two lines I mention in the update as an inline import inside the method. Can you come up with a cleaner way? — Andres, May 11 '16 at 23:53
With Python 2.7 and Django 1.9.6 it appears to work without changing handlers. — John Percival Hackworth, May 12 '16 at 00:25

score 0 · Answer 2 · answered May 11 '16 at 23:55

If you move the following lines (model imports) https://github.com/andresdouglas/django-shopify-sync/blob/master/shopify_sync/handlers.py#L3-L4

from .models import (CustomCollection, Customer, Order, Product, Shop,
                 SmartCollection)

inside get_topic_models it seems to fix the error. But that's kind of dirty, can anyone come up with a better solution?

Django 1.9 django.core.exceptions.AppRegistryNotReady: Apps aren't loaded yet

2 Answers2