How to solve the a celery worker configuration with keyword argument namespace='"CELERY"error in the celery file

Question

I have a project name called ShippingApp and I followed the steps to set up the celery worker. I am using celery 3.1.26.post2 with python3.7 and when I want to start the Celery Worker I am getting the error below:

E:\ShippingApp>celery -A ShippingApp worker -l info
Traceback (most recent call last):
  File "c:\program files\python37\lib\runpy.py", line 193, in _run_module_as_main
    "__main__", mod_spec)
  File "c:\program files\python37\lib\runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "C:\Program Files\Python37\Scripts\celery.exe\__main__.py", line 9, in <module>
  File "c:\program files\python37\lib\site-packages\celery\__main__.py", line 30, in main
    main()
  File "c:\program files\python37\lib\site-packages\celery\bin\celery.py", line 81, in main
    cmd.execute_from_commandline(argv)
  File "c:\program files\python37\lib\site-packages\celery\bin\celery.py", line 793, in execute_from_commandline
    super(CeleryCommand, self).execute_from_commandline(argv)))
  File "c:\program files\python37\lib\site-packages\celery\bin\base.py", line 309, in execute_from_commandline
    argv = self.setup_app_from_commandline(argv)
  File "c:\program files\python37\lib\site-packages\celery\bin\base.py", line 469, in setup_app_from_commandline
    self.app = self.find_app(app)
  File "c:\program files\python37\lib\site-packages\celery\bin\base.py", line 489, in find_app
    return find_app(app, symbol_by_name=self.symbol_by_name)
  File "c:\program files\python37\lib\site-packages\celery\app\utils.py", line 235, in find_app
    sym = symbol_by_name(app, imp=imp)
  File "c:\program files\python37\lib\site-packages\celery\bin\base.py", line 492, in symbol_by_name
    return symbol_by_name(name, imp=imp)
  File "c:\program files\python37\lib\site-packages\kombu\utils\__init__.py", line 96, in symbol_by_name
    module = imp(module_name, package=package, **kwargs)
  File "c:\program files\python37\lib\site-packages\celery\utils\imports.py", line 101, in import_from_cwd
    return imp(module, package=package)
  File "c:\program files\python37\lib\importlib\__init__.py", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1006, in _gcd_import
  File "<frozen importlib._bootstrap>", line 983, in _find_and_load
  File "<frozen importlib._bootstrap>", line 967, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 677, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 728, in exec_module
  File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
  File "E:\ShippingApp\ShippingApp\__init__.py", line 2, in <module>
    from .celery import app as celery_app
  File "E:\ShippingApp\ShippingApp\celery.py", line 6, in <module>
    app.config_from_object('django.conf:settings', namespace='CELERY')
TypeError: config_from_object() got an unexpected keyword argument 'namespace'

celery.py:

import os
from celery import Celery

os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'mysite.settings')

app = Celery('mysite')
app.config_from_object('django.conf:settings', namespace='CELERY')
app.autodiscover_tasks()

init.py:

from .celery import app as celery_app

tasks.py:

from celery import task
from django.core.mail import send_mail
from .models import Order
@task
def order_created(order_id):
    """
    Task to send an e-mail notification when an order is
    successfully created.
    """
    order = Order.objects.get(id=order_id)
    subject = 'Order nr. {}'.format(order.id)
    message = 'Dear {},\n\nYou have successfully placed an order.\
    Your order id is {}.'.format(order.first_name,
    order.id)
    mail_sent = send_mail(subject,
                        message,
                        '[email protected]',
    [order.email])
    return mail_sent

In the orders view, we have the code below:

def order_create(request):
cart = Cart(request)
if request.method == 'POST':
    form = OrderCreateForm(request.POST)
    if form.is_valid():
        order = form.save()
        for item in cart:
            OrderItem.objects.create(order=order,
                                    product=item['product'],
                                    price=item['price'],
                                    quantity=item['quantity'])
        # clear the cart
        cart.clear()
        # launch asynchronous task
        order_created.delay(order.id)
        # set the order in the session
        request.session['order_id'] = order.id
        # redirect for payment
        return redirect(reverse('payment:process'))
else:
    form = OrderCreateForm()
return render(request,
            'orders/order/create.html',
            {'cart': cart, 'form': form})

Before I was using celery 4.2.1 but it was not compatible with windows 10 and I uninstall it and install the version 3.1.26.post2. Please assist.

Answer 1

The uppercase namespace means that all celery configurations must be specified with uppercase instead of lowercase, and start with CELERY_, so that for example, task_always_eager settings becomes CELERY_TASK_ALWAYS_EAGER, and the broker_url becomes CELERY_BROKER_URL ans so on. This configuration was introduced from celery4.0 onwards.

So, for version <4 you don't need namespace in line:

app.config_from_object('django.conf:settings', namespace='CELERY')

Replace the above with:

app.config_from_object('django.conf:settings')

NOTE: If you use celery 3.1, please check your Django version. It should be <1.8