Here is a structured list of Top 50 Django Interview Questions that cover various important topics, ranging from basic concepts to advanced Django features. These questions are designed to test your knowledge in Django and are commonly asked in interviews.
1. What is Django?
Django is a high-level Python web framework that promotes rapid development and clean, pragmatic design. It follows the MVT (Model-View-Template) architectural pattern and provides many built-in tools for database management, security, and other common web development tasks.
2. What is the difference between Django and Flask?
Django is a full-stack framework with built-in components for things like authentication, database handling, form processing, etc.
Flask is a micro-framework, meaning it is lightweight and provides the bare essentials, requiring you to add third-party libraries for full functionality.
3. What are the key features of Django?
- MVT Architecture (Model-View-Template)
- Admin Interface
- ORM (Object-Relational Mapping)
- URL Routing
- Security Features (CSRF protection, SQL injection prevention)
- Development Tools (Auto-reload, debugging, etc.)
- Scalability and Extensibility
4. What is the MVT architecture?
MVT stands for Model-View-Template:
Model: Defines the data structure (database schema).
View: Manages the logic and processes user requests.
Template: Defines the HTML structure and presentation.
5. What are Django Models?
Django Models are Python classes that define the structure of your database tables. They define fields and behaviors of the data you store in the database.
6. What is a Django view?
A view in Django is a Python function that takes a web request and returns a web response. Views can render HTML content, redirect to another URL, or return data as JSON.
7. What is a Django template?
Django templates allow you to separate the presentation logic from the business logic in the view. They are HTML files with Django Template Language (DTL) used to embed dynamic content like variables, loops, and conditionals.
8. Explain URL routing in Django.
URL routing in Django maps URLs to view functions. It is done through the urls.py file where you define URL patterns and associate them with specific views.
9. What is Django ORM?
Django ORM (Object-Relational Mapping) allows you to interact with your database, using Python objects instead of SQL queries. It maps the models to database tables, and you can create, retrieve, update, and delete data using Python code.
10. How do you create a Django project?
You can create a Django project using the following command:
django-admin startproject project_name
11. How do you create a Django app?
Use the following command to create a Django app:
python manage.py startapp app_name
12. What is the purpose of the manage.py file?
The manage.py file is a command-line utility for interacting with a Django project. It allows you to run server, apply migrations, create database schemas, and many other tasks.
13. What is Django Admin?
Django Admin is an auto-generated interface for managing your site’s data. It allows users to manage the content in your models via a web interface.
14. How does Django handle static files?
Static files (like CSS, JavaScript, and images) are stored in a static folder, and Django serves them during development. In production, these files are collected using the collectstatic command and served by a web server like Nginx or Apache.
15. What are Django signals?
Django signals allow decoupled applications to get notified when certain actions occur in the application, like saving a model, pre/post-save, etc. They allow one part of the application to send a signal and another to receive it.
16. What are migrations in Django?
Migrations in Django are a way of propagating changes you make to your models (like adding/removing fields) into your database schema. You can create migrations using python manage.py makemigrations and apply them with python manage.py migrate.
17. How do you handle forms in Django?
Django provides a forms module that helps to generate HTML forms, validate input, and process the form data. You can use forms.Form and forms.ModelForm to define forms.
18. What are class-based views (CBVs)?
Class-based views are a way of writing views using Python classes. They allow for reusable views and better separation of concerns. Examples include ListView, DetailView, CreateView, etc.
19. What are function-based views (FBVs)?
Function-based views are the traditional way of writing views in Django using Python functions. Each view function receives a request object and returns a response.
20. What is a middleware in Django?
Middleware is a lightweight, low-level plugin that processes requests and responses globally. They are used for functions like authentication, logging, and session management.
21. What is Django’s default authentication system?
Django comes with a built-in authentication system that handles user login, registration, password management, and permissions.
22. What is the difference between GET and POST methods?
GET: Retrieves data from the server. It is idempotent (does not change the state).
POST: Sends data to the server, typically used for form submissions or creating resources.
23. How do you set up a database in Django?
In Django, you configure the database connection in the DATABASES setting in settings.py. Django supports databases like SQLite, MySQL, PostgreSQL, and others.
24. How do you protect against SQL injection in Django?
Django ORM automatically escapes queries, protecting against SQL injection. It also prevents direct database queries and forces the use of safe query methods.
25. How do you enable CSRF protection in Django?
Django has CSRF protection enabled by default. It requires the use of {% csrf_token %} in forms to include a token that must match when the form is submitted.
26. What is Django REST Framework (DRF)?
Django REST Framework (DRF) is a powerful toolkit for building Web APIs in Django. It simplifies tasks like serialization, authentication, and view routing for API development.
27. How do you handle database relationships in Django?
Django supports several types of relationships:
One-to-Many: ForeignKey
Many-to-Many: ManyToManyField
One-to-One: OneToOneField
28. What is a foreign key in Django?
A foreign key is a field in one model that links to the primary key of another model, creating a relationship between them.
29. What is a ManyToManyField in Django?
A ManyToManyField represents a many-to-many relationship where each record in the related model can be associated with multiple records in the other model.
30. What is a OneToOneField in Django?
A OneToOneField is used to define a one-to-one relationship between two models, where each record in one model is associated with exactly one record in another model.
31. How do you handle user authentication in Django?
Django provides an authentication system out-of-the-box. You can use django.contrib.auth for login, logout, and user management.
32. How do you handle file uploads in Django?
File uploads are handled using the FileField or ImageField in Django models, and the uploaded file is saved to a specific directory specified in MEDIA_ROOT setting.
33. What are Django settings?
Django settings define the configuration of your project. These include database settings, template paths, static files, installed apps, etc. The main settings file is settings.py.
34. How do you deploy a Django application?
Django applications can be deployed using a web server like Nginx or Apache, coupled with Gunicorn or uWSGI as the WSGI server. The database, static files, and security measures need to be properly configured in production.
35. What is Django’s SESSION_ENGINE?
SESSION_ENGINE defines where Django stores session data (like in the database, cache, or filesystem). The default is django.contrib.sessions.backends.db.
36. What are Django’s QuerySets?
A QuerySet is a collection of database queries in Django. It allows you to retrieve, filter, update, and delete data from the database. QuerySets are lazy, meaning the actual database query is executed only when the data is needed.
37. What is the @login_required decorator in Django?
The @login_required decorator is used to restrict access to views that require the user to be authenticated. If an unauthenticated user tries to access a view with this decorator, they will be redirected to the login page.
38. How can you implement pagination in Django?
Pagination in Django can be implemented using the Paginator class. You can pass a QuerySet and the number of items per page to the paginator, then get the specific page and items using page_number and paginator.get_page().
39. What are views.py, urls.py, and models.py in Django?
views.py: Contains the logic of the application and how to process requests and return responses.
urls.py: Maps URLs to views using URL patterns.
models.py: Defines the structure of the database and the ORM mappings.
40. What are Django’s class-based generic views?
Django provides generic views for common actions like displaying a list of items (ListView), displaying details for a single item (DetailView), and creating, updating, or deleting objects (CreateView, UpdateView, DeleteView). These views handle common patterns with minimal code.
41. What is a context in Django?
A context is a dictionary that holds data to be passed from a view to a template. This data is rendered dynamically in the template to produce the final output sent to the user.
42. What is a render() function in Django?
The render() function is used to combine a template with a context dictionary and return an HTTP response. It is a shortcut for generating a response with a template.
Example:
return render(request, 'template_name.html', {'key': value})
43. What is the difference between render() and HttpResponse() in Django?
render() is used to render a template with context and return an HTTP response.
HttpResponse() is a more general function used to return an HTTP response with plain content (like text, JSON, or HTML).
44. What is a Django model manager?
A model manager is a class that provides extra methods to interact with a model’s database. The default manager in Django is objects, but you can create custom managers to encapsulate specific query logic.
45. What is Django Rest Framework (DRF)?
Django Rest Framework (DRF) is a toolkit used to build web APIs in Django. It simplifies creating RESTful APIs by providing features like serializers, authentication, viewsets, and routers.
46. What is a Django serializer?
A serializer in Django is used to convert complex data types, like Django models, into Python data types (usually dictionaries) that can then be rendered into JSON, XML, or other content types.
47. What is the purpose of the __str__() method in Django models?The __str__() method in Django models defines how a model instance should be represented as a string. This method is helpful for displaying model instances in the Django admin or other interfaces.
48. What is the purpose of the urlpatterns list in Django?
The urlpatterns list is where you define the URL routing in Django. Each URL pattern is mapped to a specific view, enabling the application to handle different routes and return appropriate responses.
49. What is the static folder used for in Django?
The static folder in Django is used to store static files like CSS, JavaScript, and images that are served directly to users. These files are typically used in the presentation layer (i.e., templates).
50. What is the purpose of django.contrib.sites?
django.contrib.sites is a framework used to associate different sites with different pieces of content in Django. It allows managing multiple websites from a single Django project by associating models and content with specific domains.