How to properly do monkey Patching on Django 3.1 - python

i'm currently coding a web application with django 3.0 and trying to override some functions of an installed django apps (Python social auth module). I want to do it because i want to change the default behavior.
I have found some method to perform overriding of a module (monkey patching) and try to implement it but i the following errors when i try to implement it :
File "/Users/***********/code/recrutlocataire/recrutlocataire/core/__init__.py", line 1, in <module>
import core.monkey
File "/Users/***********/code/recrutlocataire/recrutlocataire/core/monkey.py", line 6, in <module>
from django.contrib.sessions.models import Session
File "/usr/local/lib/python3.8/site-packages/django/contrib/sessions/models.py", line 1, in <module>
from django.contrib.sessions.base_session import (
File "/usr/local/lib/python3.8/site-packages/django/contrib/sessions/base_session.py", line 26, in <module>
class AbstractBaseSession(models.Model):
File "/usr/local/lib/python3.8/site-packages/django/db/models/base.py", line 107, in __new__
app_config = apps.get_containing_app_config(module)
File "/usr/local/lib/python3.8/site-packages/django/apps/registry.py", line 252, in get_containing_app_config
self.check_apps_ready()
File "/usr/local/lib/python3.8/site-packages/django/apps/registry.py", line 135, in check_apps_ready
raise AppRegistryNotReady("Apps aren't loaded yet.")
django.core.exceptions.AppRegistryNotReady: Apps aren't loaded yet.
Create my patch in the monkey.py file in my application directory:
core/monkey.py
from social_core import utils
from social_core.exceptions import InvalidEmail
from django.core import signing
from django.core.signing import BadSignature
from django.contrib.sessions.models import Session
from django.conf import settings
def partial_pipeline_data(backend, user=None, *args, **kwargs):
pass
Import the monkey file in the init file located in my application directory :
core/init.py
import core.monkey
It seems that I have this error because I'm trying to import the session module whereas the application loading is not done but i cannot find a proper way to do it.
Could someone tell me how can I perform it properly please ?

Related

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

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?
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?
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')
+

Not able to modify DataBase with django

I am new to django. Want to create tables in the Database of my project, so I searched the tutorial.
models.py:
from django.db import models
class Blah(models.Model):
first = models.IntegerField()
second = models.IntegerField()
Script to write data into db:
from django.conf import settings
settings.configure()
from core.models import Blah
b = Blah(first = 1, second = 2)
b.save()
When I am trying to launch the script with django 1.9, it gives me the error:
C:\Python27\Scripts\reports>to_db.py
Traceback (most recent call last):
File "C:\Python27\Scripts\reports\to_db.py", line 4, in <module>
from core.models import Blah
File "C:\Python27\Scripts\reports\core\models.py", line 5, in <module>
class Blah(models.Model):
File "C:\Python27\lib\site-packages\django\db\models\base.py", line 94, in __new__
app_config = apps.get_containing_app_config(module)
File "C:\Python27\lib\site-packages\django\apps\registry.py", line 239, in get_containing_app_config
self.check_apps_ready()
File "C:\Python27\lib\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.
I have already added the app to INSTALLED_APPS and I am able to do the exact same commands with "manage.py shell", but not with the script.
What am I missing here?
Thanks
If you do need to script against Django (and the ORM), you'll want to use the shell admin command, passing your script as input to it. Related question

Can't import django.db.models from Python GUI

Whenever I type this command in Python GUI:
from django.db import models
it gives me an error like this
Traceback (most recent call last):
File "<pyshell#12>", line 1, in <module>
from django.db import models
File "C:\Python27\lib\site-packages\django\db\models\__init__.py", line 5, in <module>
from django.db.models.query import Q
File "C:\Python27\lib\site-packages\django\db\models\query.py", line 17, in <module>
from django.db.models.deletion import Collector
File "C:\Python27\lib\site-packages\django\db\models\deletion.py", line 4, in <module>
from django.db.models import signals, sql
File "C:\Python27\lib\site-packages\django\db\models\sql\__init__.py", line 4, in <module>
from django.db.models.sql.subqueries import *
File "C:\Python27\lib\site-packages\django\db\models\sql\subqueries.py", line 12, in <module>
from django.db.models.sql.query import Query
File "C:\Python27\lib\site-packages\django\db\models\sql\query.py", line 22, in <module>
from django.db.models.sql import aggregates as base_aggregates_module
File "C:\Python27\lib\site-packages\django\db\models\sql\aggregates.py", line 9, in <module>
ordinal_aggregate_field = IntegerField()
File "C:\Python27\lib\site-packages\django\db\models\fields\__init__.py", line 116, in __init__
self.db_tablespace = db_tablespace or settings.DEFAULT_INDEX_TABLESPACE
File "C:\Python27\lib\site-packages\django\conf\__init__.py", line 54, in __getattr__
self._setup(name)
File "C:\Python27\lib\site-packages\django\conf\__init__.py", line 47, in _setup
% (desc, ENVIRONMENT_VARIABLE))
ImproperlyConfigured: Requested setting DEFAULT_INDEX_TABLESPACE, but settings are not configured. You must either define the environment variable DJANGO_SETTINGS_MODULE or call settings.configure() before accessing settings.
What can it be the problem? I have django in directory C:\Python27\Lib\site-packages\django\db and in there i have a file called models.
This is the pic
Bizarre isn't it?
Not all of Django supports simply being loaded as a Python module, unfortunately; you need to use the means provided by Django itself to bootstrap the environment needed to load stuff like models.
One option is to use the Django shell but it's also possible to use a purely programmatic solution from your own code. See https://docs.djangoproject.com/en/dev/topics/settings/ for all the options.
Here's also an example by somebody else https://gist.github.com/jordanorelli/1025419 but I haven't verified if it's up to date.
The answer is in the error message:
You must either define the environment variable DJANGO_SETTINGS_MODULE or...
For this reason Django provides a shortcut to loading a python shell with Django settings configured:
https://docs.djangoproject.com/en/dev/ref/django-admin/#shell

Using a Django model from a mercurial python hook

I'm trying to queue up some build requests in a DB during a changegroup hook. The DB table is managed by a Django app. So, in the hook, I want to use the Django model to submit the build request. However, I'm unable to get my settings right to import the model successfully.
Based on this (https://docs.djangoproject.com/en/1.3/ref/django-admin/) info, all I need to do is add my django site to the sys path, and set the DJANGO_SETTINGS_MODULE. The django site lives in /opt/mysite, so - trying this from the python console:
>>> import sys
>>> import os
>>> sys.path.append('/opt')
>>> os.environ['DJANGO_SETTINGS_MODULE'] = 'mysite.settings'
>>> from mysite.myapp.models import Build
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/opt/mysite/myapp/models.py", line 1, in <module>
from django.db import models
File "/usr/lib/pymodules/python2.7/django/db/__init__.py", line 78, in <module>
connection = connections[DEFAULT_DB_ALIAS]
File "/usr/lib/pymodules/python2.7/django/db/utils.py", line 93, in __getitem__
backend = load_backend(db['ENGINE'])
File "/usr/lib/pymodules/python2.7/django/db/utils.py", line 33, in load_backend
return import_module('.base', backend_name)
File "/usr/lib/pymodules/python2.7/django/utils/importlib.py", line 35, in import_module
__import__(name)
File "/usr/lib/pymodules/python2.7/django/db/backends/mysql/base.py", line 28, in <module>
from django.db import utils
ImportError: cannot import name utils
>>>
Second Attempt:
Based on this (http://www.b-list.org/weblog/2007/sep/22/standalone-django-scripts/) I can use setup_environ(), when I try this in the python shell, it works:
>>> import sys
>>> sys.path.append('/opt')
>>> from django.core.management import setup_environ
>>> from mysite import settings
>>> setup_environ(settings)
'/opt/mysite'
>>> from mysite.myapp.models import Build
>>> Build.objects.all()
[<Build: #1 F nkj sdfsdfsdfs43qg test_branch>, <Build: #2 F nkj sdfsdfsdfs43qg test_branch>, <Build: #13 Q >, <Build: #14 Q nkj_bug243>, <Build: #11 F nkj 444hwe45hedrrt nkj_bug272>, <Build: #12 F nkj sdfsdfsdfs43qg test_branch>]
However, when I try this in my Mercurial hook, I get blasted with errors the minute I try to import my Build model:
#!/usr/bin/env python
import sys
path = '/opt'
if path not in sys.path:
sys.path.append(path)
from django.core.management import setup_environ
from mysite import settings
setup_environ(settings)
from mysite.myapp.models import Build
import datetime
... do stuff ...
When it gets to the 'from mysite.myapp.models import Build' line I get the following error output:
** unknown exception encountered, please report by visiting
** http://mercurial.selenic.com/wiki/BugTracker
** Python 2.7.2+ (default, Oct 4 2011, 20:06:09) [GCC 4.6.1]
** Mercurial Distributed SCM (version 1.9.1)
** Extensions loaded:
Traceback (most recent call last):
File "/usr/bin/hg", line 38, in <module>
mercurial.dispatch.run()
File "/usr/lib/python2.7/dist-packages/mercurial/dispatch.py", line 27, in run
sys.exit(dispatch(request(sys.argv[1:])))
File "/usr/lib/python2.7/dist-packages/mercurial/dispatch.py", line 64, in dispatch
return _runcatch(req)
File "/usr/lib/python2.7/dist-packages/mercurial/dispatch.py", line 87, in _runcatch
return _dispatch(req)
File "/usr/lib/python2.7/dist-packages/mercurial/dispatch.py", line 679, in _dispatch
cmdpats, cmdoptions)
File "/usr/lib/python2.7/dist-packages/mercurial/dispatch.py", line 454, in runcommand
ret = _runcommand(ui, options, cmd, d)
File "/usr/lib/python2.7/dist-packages/mercurial/dispatch.py", line 733, in _runcommand
return checkargs()
File "/usr/lib/python2.7/dist-packages/mercurial/dispatch.py", line 687, in checkargs
return cmdfunc()
File "/usr/lib/python2.7/dist-packages/mercurial/dispatch.py", line 676, in <lambda>
d = lambda: util.checksignature(func)(ui, *args, **cmdoptions)
File "/usr/lib/python2.7/dist-packages/mercurial/util.py", line 385, in check
return func(*args, **kwargs)
File "/usr/lib/python2.7/dist-packages/mercurial/commands.py", line 3884, in push
newbranch=opts.get('new_branch'))
File "/usr/lib/python2.7/dist-packages/mercurial/localrepo.py", line 1428, in push
lock=lock)
File "/usr/lib/python2.7/dist-packages/mercurial/localrepo.py", line 1849, in addchangegroup
source=srctype, url=url)
File "/usr/lib/python2.7/dist-packages/mercurial/localrepo.py", line 224, in hook
return hook.hook(self.ui, self, name, throw, **args)
File "/usr/lib/python2.7/dist-packages/mercurial/hook.py", line 160, in hook
mod = extensions.loadpath(path, 'hghook.%s' % hname)
File "/usr/lib/python2.7/dist-packages/mercurial/extensions.py", line 45, in loadpath
return imp.load_source(module_name, path)
File "/opt/unapse/belvedere/mercurial_hook.py", line 14, in <module>
from unapse.belvedere.models import Build
File "/usr/lib/python2.7/dist-packages/mercurial/demandimport.py", line 109, in _demandimport
mod = _origimport(name, globals, locals)
File "/opt/unapse/belvedere/models.py", line 1, in <module>
from django.db import models
File "/usr/lib/python2.7/dist-packages/mercurial/demandimport.py", line 109, in _demandimport
mod = _origimport(name, globals, locals)
File "/usr/lib/pymodules/python2.7/django/db/__init__.py", line 14, in <module>
if not settings.DATABASES:
File "/usr/lib/pymodules/python2.7/django/utils/functional.py", line 276, in __getattr__
self._setup()
File "/usr/lib/pymodules/python2.7/django/conf/__init__.py", line 42, in _setup
self._wrapped = Settings(settings_module)
File "/usr/lib/pymodules/python2.7/django/conf/__init__.py", line 139, in __init__
logging_config_func(self.LOGGING)
File "/usr/lib/python2.7/logging/config.py", line 776, in dictConfig
dictConfigClass(config).configure()
File "/usr/lib/python2.7/logging/config.py", line 575, in configure
'%r: %s' % (name, e))
ValueError: Unable to configure handler 'mail_admins': __import__() argument 1 must be string, not DictConfigurator
Any ideas as to what could be causing this problem?
The DictConfigurator error is a bug in python, hopefully fixed in the next 2.7 release (http://bugs.python.org/issue12718), something (probably mercurial) is overriding import and python's logging code fails in that case.
Until then here is what I did to fix it. Copy dictconfig.py from django/utils to somewhere in your python system path (I put it alongside my hook). Change the line
importer = __import__
to:
def importer(self, *args):
return __import(*args)__
And then in settings.py for your django project add to the end:
LOGGING_CONFIG = 'website.dictconfig.dictConfig'
Update website.dictconfig to whatever path you put the dictconfig file into so python can find it.
UPDATE: I think there is an even easier way. Add this to the top of your hook script, before importing anything else:
from mercurial import demandimport;
demandimport.disable()
This makes Mercurial revert the import override and seems to solve the problem cleanly.
If you're running with your environment in a virtualenv dir you'll need to add that to the site packages and I'd also suggest that you put the django dir at the front of sys.path instead of the end.
Here's the code we use to integrate our Django app into other python apps.
import os
import sys
# point this at the virtualenv dir that your django deployment runs out of
# you are using virtualenv. right?
DJANGO_ENV = '/home/core/python-envs/production'
# where your code lives (ie where settings.py is)
DJANGO_DIR = '/home/core/code/production'
# add our site packages
import site
site_packages = os.path.join(DJANGO_ENV, 'lib', 'python%s' % sys.version[:3], 'site-packages')
site.addsitedir(site_packages)
# put the main Django directory on first
sys.path.insert(0, DJANGO_DIR)
# setup the Django environment pointing to our settings
import settings
import django.core.management
django.core.management.setup_environ(settings)
# finally, import our objects
from yourapp.models import YourModel
One last thing to note is that when we import our code into some applications we've run into scoping issues and imports clashing. To get around it we wrap the work we want to do in a function so that it gets its own scope.
For example, instead of:
from yourapp.models import YourModel
objs = YourModel.objects.filter(something=True)
...
Do something like:
def do_work():
from yourapp.models import YourModel
objs = YourModel.objects.filter(something=True)
...
do_work()

django models recursive imports - how to resolve

I have a model project_phase:
from django.db import models
from django.utils import simplejson
from core.models import pmo_review_task
it references pmo_review_task (because it creates a pmo_review_task in its save ovewrite)
from django.db import models
from datetime import datetime
from django.contrib.auth.models import User
from core.models import sc_review_task
which references sc_review_task that references project_phase (because it creates a project_phase in its save ovewrite)
from django.db import models
from core.models import project_phase
so it ends up project_phase imports pmo_review_task imports sc_review_task imports project_phase and I guess it loops up somehow generating this error:
Unhandled exception in thread started by <bound method Command.inner_run of <django.core.management.commands.runserver.Command object at 0x010ACFB0>>
Traceback (most recent call last):
File "C:\Python27\lib\site-packages\django\core\management\commands\runserver.py", line 88, in inner_run
self.validate(display_num_errors=True)
File "C:\Python27\lib\site-packages\django\core\management\base.py", line 249, in validate
num_errors = get_validation_errors(s, app)
File "C:\Python27\lib\site-packages\django\core\management\validation.py", line 35, in get_validation_errors
for (app_name, error) in get_app_errors().items():
File "C:\Python27\lib\site-packages\django\db\models\loading.py", line 146, in get_app_errors
self._populate()
File "C:\Python27\lib\site-packages\django\db\models\loading.py", line 64, in _populate
self.load_app(app_name)
File "C:\Python27\lib\site-packages\django\db\models\loading.py", line 78, in load_app
models = import_module('.models', app_name)
File "C:\Python27\lib\site-packages\django\utils\importlib.py", line 35, in import_module
__import__(name)
File "C:\work\Portman\core\models\__init__.py", line 4, in <module>
from pmo_review_task import pmo_review_task
File "C:\work\Portman\core\models\pmo_review_task.py", line 5, in <module>
from core.models import sc_review_task
File "C:\work\Portman\core\models\sc_review_task.py", line 3, in <module>
from core.models import project_phase
File "C:\work\Portman\core\models\project_phase.py", line 4, in <module>
from core.models import pmo_review_task
ImportError: cannot import name pmo_review_task
how do I overcome this?
Two ways:
To import a model inside a method (as #YujiTomita suggested).
To use get_model function from django.db.models which is designed for lazy model imports.:
project_phase = get_model('core', 'project_phase')
I prefer the second one, but both methods are ok.
import project_phase inside the save method.
The import is called whenever the code is executed.
If it's in the global module namespace (at the top) then it's called right away and you'll have circular import problems as you describe because one file imports another file which imports the original file.
If you put the problem import statement inside a function, it is /not/ called upon importing the file.
import foo # executed upon importing this file.
def import_foo_when_called():
import foo # only executed when function is called, thus no problems when
# another module imports this file.
Django 1.9 and above
As get_model() in django.db.models has been removed in 1.9.
Use django.apps.get_model()
Similar Question:
What is the equivalent of django.db.models.loading.get_model() in Django 1.9?
or use application label in quotes if you are just using it to create foreignkey.
Instead of from core.models import project_phase
do
models.ForeignKey("core.project_phase")

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