Celery installation and setup in Django - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

What is the primary role of Celery in a Django project?

Choose the best description of what Celery does when integrated with Django.

A It replaces Django's ORM for database queries.

B It serves static files like CSS and JavaScript.

C It manages user authentication and permissions.

D It handles asynchronous task execution outside the main web request cycle.

💡 Hint

Think about tasks that run separately from immediate user requests.

Celery allows Django to run tasks asynchronously, meaning tasks can be processed in the background without blocking the main web server.

📝 Syntax

intermediate

Which command correctly installs Celery for a Django project?

Select the exact pip command to install Celery compatible with Django.

A pip install celery-django

B pip install celery

C pip install celery==4.0

D pip install django-celery

💡 Hint

Celery is installed as a standalone package, not a Django-specific package.

The correct package to install is 'celery'. The 'django-celery' package is outdated and no longer recommended.

❓ component_behavior

advanced

What happens if you forget to start the Celery worker after setup?

After configuring Celery in Django, what is the result if you do NOT run the Celery worker process?

A Tasks sent to Celery will remain pending and never execute.

B Django will automatically start the worker in the background.

C Tasks will execute immediately in the main Django process.

D The Django server will crash on task submission.

💡 Hint

Consider how Celery processes tasks separately from Django.

Celery workers must be running to pick up and execute tasks. Without workers, tasks queue up but do not run.

🔧 Debug

advanced

Identify the error in this Celery setup snippet

Given this Celery app setup in Django, what error will occur? code: from celery import Celery app = Celery('proj') app.config_from_object('django.conf:settings', namespace='CELERY') app.autodiscover_tasks() Options:

A No error; this is a correct Celery setup snippet

B ImportError due to incorrect import of Celery

C AttributeError because autodiscover_tasks requires an argument

D TypeError because config_from_object is missing parentheses

💡 Hint

Check method calls and parameters carefully.

The snippet correctly creates a Celery app, loads Django settings with the proper namespace, and autodiscovers tasks without arguments.

❓ state_output

expert

What is the output when calling a Celery task synchronously with .delay()?

Consider this Celery task in Django: @celery_app.task def add(x, y): return x + y What is the type and value of result when calling result = add.delay(4, 5)?

A A string '9' returned immediately

B The integer 9 returned immediately from the function

C An AsyncResult object representing the task; value is not immediately available

D None, because delay does not return anything

💡 Hint

Think about how Celery handles task calls asynchronously.

Calling .delay() queues the task and returns an AsyncResult object immediately. The actual result is computed later by a worker.