Ultimate List of 90 Django Interview Questions You Need To Know

This is an Ultimate List of Django Questions and topics you need to know in order to master the Django Web Framework.

1. What is Django?

A. A programming language
B. A web development framework
C. A database management system
D. A version control system

Answer: B

Django is a high-level Python web framework that allows developers to build web applications
quickly and efficiently. To read more about what is Django, read this article.

2. What does MTV stand for in Django?

A. Model Template View
B. Model Text View
C. Model Tag View
D. Model Test View

Answer: A

In the MVT pattern, the Model is responsible for handling the data and business logic of the application, the View handles the user interface and presentation logic, and the Template handles the presentation of data.

The main difference between MVT and MVC is that in MVT, the Template is responsible for handling the presentation logic, whereas in MVC, this responsibility is typically handled by the View.

In Django’s implementation of MVT:

• Model: database schema and the Python code that interacts with it through the Django ORM.
• View: Python functions or classes that handle requests and responses
• Template: HTML files that define the structure and layout of the pages

To read more about Django’s MVT structure in detail click here

3. What is the default database backend in Django?

A. MySQL
B. SQLite
C. PostgreSQL
D. Oracle

Answer: B

The default database backend in Django is SQLite. When you create a new Django project, it is set up
to use SQLite as the default database engine. SQLite is a lightweight, serverless, and file-based database that is easy to set up and use, making it a great choice for small to medium-sized projects.
However, Django supports many other popular databases such as PostgreSQL, MySQL, Oracle, and
Microsoft SQL Server, so you can choose the database that best fits your project’s requirements. You
can configure Django to use a different database by changing the DATABASES setting in your project’s settings.py file, and installing the appropriate database driver.

4. What is the purpose of Django’s built-in admin interface?

A. To allow users to interact with external APIs
B. To enable user authentication and authorization
C. To provide a user-friendly interface for managing database records
D. To provide a development environment for testing code

Answer: C

The purpose of Django’s built-in admin interface is to provide a user-friendly web-based interface
allowing you to add, edit, and delete records in your database without writing any custom views or
templates. The admin interface is automatically generated based on the models defined in your Django project. With it you can easily manage users, groups, permissions, content types, and other site-specific data.

Overall, the admin interface makes it easy to manage the content and functionality of your Django powered website or web application, without requiring you to write custom views or templates for basic CRUD (Create, Read, Update, Delete) operations.

5. What is the Django shell?

A. A command-line interface for interacting with Django models
B. A web interface for managing Django applications
C. A tool for testing Django views
D. A version control system for Django projects

Answer: A

The Django shell is a command-line interface provided by Django that allows you to interact with your Django project’s database and models using Python code. It’s a powerful tool that can be used for testing and debugging as well as for performing bulk operations on your data.

6. What is a Django view?

A. A class that defines the behaviour of a web form
B. A template that defines the HTML structure of a web page
C. A model that defines the database schema
D. A function that handles a specific URL request

Answer: D

In Django, a view is a Python function or method that takes a web request and returns a web
response. In other words, a view is responsible for processing a user’s request and returning the
appropriate HTML content, JSON response, or other content types.

When a user visits a URL in a Django web application, the URL routing system maps the URL to a
view function or method that can handle that request. The view function or method then performs any necessary logic, such as querying the database, processing user input, or manipulating data, and then returns an HTTP response object that can be displayed in the user’s web browser. Views can be simple or complex, depending on the needs of the application. They can interact with models, templates, and other components of the application to generate dynamic web content.

Views can also be decorated with middleware to provide additional functionality, such as caching,
authentication, or rate limiting.

7. What is the purpose of Django’s URL dispatcher?

A. To manage user authentication and authorization
B. To map URLs to view functions
C. To define the structure of the database schema
D. To handle HTTP requests and responses

Answer: B

Django’s URL dispatcher is a core component of the framework that maps URLs to views. Its
primary purpose is to direct incoming HTTP requests to the appropriate view function or class based on the URL requested. When a user visits a URL in a Django web application, the URL dispatcher uses regular expressions and other matching rules to determine which view should be executed to handle the request. The URL dispatcher can also pass along any additional parameters or data contained in the URL to the view function, allowing it to process the request and generate an appropriate response.

The URL dispatcher provides a high degree of flexibility in how URLs are structured and mapped to
views, allowing developers to create clean, RESTful URLs that are easy to understand and maintain. It also supports a range of advanced features, such as URL namespaces, regular expression capture groups, and custom URL converters, that can be used to handle complex routing requirements.
Overall, the URL dispatcher is a powerful and flexible component of Django that allows developers to create well-organized, scalable web applications with clean, maintainable URLs.

8. What is a Django template?

A. A file that defines the HTML structure of a web page
B. A function that handles a specific URL request
C. A model that defines the database schema
D. A class that defines the behaviour of a web form

Answer: A

In Django, a template is a text file that defines the structure and layout of a web page. Templates are used to separate the presentation logic from the business logic in a web application, making it easier to develop and maintain complex user interfaces.

Django templates use a simple syntax that allows developers to insert dynamic content into HTML
pages. Templates can contain variables, which are replaced with values at runtime, as well as template tags and filters, which provide more complex logic and control flow. Template tags and filters can be used to perform operations such as loops, conditionals, and string formatting.

When a view function or class returns an HTTP response in Django, it typically includes a rendered
template as part of the response. The template is processed by the Django template engine, which
evaluates the template tags and filters and replaces the variables with their corresponding values. The resulting HTML is then sent to the user’s web browser as part of the HTTP response.

Django provides a number of built-in template tags and filters, as well as the ability to define custom
tags and filters for more advanced use cases. Templates can also be extended and included in other
templates, making it easy to reuse common HTML elements across multiple pages.

9.What is the purpose of Django’s migration system?

A. To handle HTTP requests and responses
B. To manage user authentication and authorization
C. To create and modify database tables and fields
D. To define the structure of the database schema

Answer: C

In Django, the migration system is a tool that manages changes to the database schema over time.
Its purpose is to make it easy for developers to make changes to the database structure without losing data or requiring manual intervention.

When a developer makes changes to the models in a Django application, such as adding or removing
fields or tables, they create a new migration that describes the change. The migration system then
applies the migration to the database, making the necessary changes to the schema. The migration system keeps track of the current state of the database schema and the history of all migrations that have been applied. This allows developers to easily roll back changes, migrate between different versions of the database schema, and collaborate on database changes with other team members.

The migration system is a key component of Django’s “batteries included” philosophy, which emphasizes the importance of providing developers with tools that work out of the box and can be used to build complex, scalable web applications with minimal effort. By providing a robust, reliable
migration system, Django makes it easier for developers to manage changes to the database schema and focus on building great applications.

10. What is a Django app?

A. A modular component of a Django project that encapsulates a specific functionality
B. A web page that displays data from a database
C. A programming language used for web development
D. A database management system

Answer: A

In Django, an app is a self-contained module that encapsulates a specific functionality of a web
application. An app is typically composed of models, views, templates, and other components that
work together to provide a specific set of features or services.

Django encourages developers to organize their code into reusable apps that can be shared across
projects. Each app can be thought of as a “plug-in” that can be added to a Django project to provide
additional functionality. For example, an e-commerce website might have separate apps for product listings, shopping cart management, and payment processing, each with its own set of models, views, and templates.

Apps in Django are structured as Python packages that contain a set of files and directories that define the app’s behavior. Each app should have a unique name and can be installed into a Django project using the INSTALLED_APPS setting in the project’s configuration file.

Django apps are designed to be modular and reusable, allowing developers to build complex web
applications by combining a set of independent, focused components. This modular approach makes it easier to manage code complexity, reuse code across projects, and collaborate with other developers on large-scale web applications.

11. Which command is used to create a new Django project?

A. django startproject
B. django-admin createproject
C. django-admin startproject
D. django createproject

Answer: C

To create a new Django project, you can use the django-admin startproject command followed by the name of your project.

For example, to create a project named myproject, you can run the following command:

django-admin startproject myproject

This will create a new directory named myproject containing the basic files and directories for a
Django project, including a settings file, a URL configuration file, and a manage.py script.
You can then start building your Django application by creating apps within the project, defining
models, views, and templates, and configuring the project settings to suit your needs.

12. Which command is used to create a new Django app?

A. django-admin createapp
B. django-admin startapp
C. django startapp
D. django createapp

Answer: B

To create a new Django app, you can use the django-admin startapp command followed by the name of your app. For example, to create an app named myapp, you can run the following command:

django-admin startapp myapp

This will create a new directory named myapp containing the basic files and directories for a Django app, including a models.py file for defining data models, a views.py file for handling HTTP requests, and a templates directory for storing HTML templates. You can then start building your app by defining models, views, and templates, and integrating it with the rest of your Django project.

13. What is the purpose of the settings.py file in a Django project?

A. To define the views for the project
B. To define the database schema
C. To define the URL patterns for the project
D. To configure various settings for the project

Answer: D

The settings.py file in a Django project is a configuration file that contains settings and options
for the project. It controls the behaviors’ of the project and specifies how different components of the project should interact with each other.

Some of the things that can be configured in the settings.py file include:

• Database settings: the database backend to use, the database name, username, password, and
  other database-specific settings.
• Installed apps: a list of apps that are installed in the project.
• Middleware classes: middleware components that process HTTP requests and responses.
• URL patterns: the routing rules that map URLs to views.
• Templates: the directory and engine to use for rendering HTML templates.
• Static files: the directory where static files (such as CSS, JavaScript, and images) are stored.

The settings.py file is an important part of a Django project, as it defines the configuration of the project and determines how it behaves. Developers can customize the settings in this file to tailor the project to their needs, such as changing the database backend or adding new middleware components.

14. Which database system does Django support?

A. MySQL
B. SQLite
C. PostgreSQL
D. All of the above

Answer: D

Django supports several database systems, including:

• PostgreSQL
• MySQL
• SQLite
• Oracle

Django provides a database abstraction layer that allows developers to write database-agnostic code, meaning that the same code can work with different database systems without modification. This abstraction layer also provides an Object-Relational Mapping (ORM) system, which allows
developers to work with database records as Python objects, rather than directly manipulating the
database.

Developers can specify which database system to use in the settings.py file of the project. Django
also provides a set of tools for creating and managing database schema migrations, which allow
developers to make changes to the database schema and apply those changes to the database in a
controlled manner.

15.Which command is used to create a new migration in Django?

A. python manage.py migrate
B. python manage.py makemigrations
C. python manage.py createmigration
D. python manage.py newmigration

Answer: B

To create a new migration in Django, you can use the python manage.py makemigrations .

16.What is the purpose of the admin.py file in a Django app?

A. To register models with the Django admin interface
B. To define URL patterns for the app
C. To define views for the app
D. To define the database schema for the app

Answer: A

The admin.py file in a Django app is used to register models with the Django admin interface.
The admin interface is a built-in feature of Django that provides a graphical user interface (GUI) for
managing site content and data.

By registering models with the admin interface, developers can provide an easy-to-use interface for site administrators to manage the content of the site without having to write custom views and templates.

In the admin.py file, developers can define a ModelAdmin class for each model that they want to
register. This class defines how the model will be displayed and edited in the admin interface, including things like the list of fields to display, filters and search options, and actions that can be performed on the model.

For example, the following code registers a Blog model with the admin interface and specifies that the list view should show the title, author, and publication date fields:

from django.contrib import admin
from .models import Blog

class BlogAdmin(admin.ModelAdmin):
            list_display = ('title', 'author', 'pub_date')
            admin.site.register(Blog, BlogAdmin)

Once the Blog model is registered with the admin interface in this way, site administrators can view
and edit the list of blog posts, filter and search the list, and perform actions like deleting or editing
individual posts.

17. Which command is used to start the Django development server?

A. python manage.py devserver
B. python manage.py startserver
C. python manage.py runserver
D. python manage.py servesite

Answer: C

To start the Django development server, you can use the python manage.py runserver command. This command will start the development server on the default port (8000) and the default IP address (127.0.0.1).

You can then open a web browser and navigate to the http://127.0.0.1:8000/ to view the site running on the development server. Any changes you make to your code will be automatically reloaded by the server, so you can see your changes in real time as you work on the project.

18. What is a Django model?

A. A Python class that defines the database schema
B. A Python function that handles a specific URL request
C. A Python module that defines the URL patterns for an app
D. A Python module that defines the views for an app

Answer: A

In Django, a model is a Python class that defines the database schema: structure and behavior of data in a relational database. A model class maps to a database table and defines the fields that the table should have, along with any additional metadata such as constraints, indexes, and relationships to other tables.

A model class is defined as a subclass of django.db.models.Model, which provides a set of methods
and attributes for working with the database. Each attribute of the model class represents a field in the database table, and can be defined with a variety of options to control things like data type, default values, and validation rules.

For example, the following code defines a simple Django model for storing information about blog
posts:

from django.db import models

class Blog(models.Model):
          title = models.CharField(max_length=200)
          content = models.TextField()
          author = models.ForeignKey('auth.User', on_delete=models.CASCADE)
          pub_date = models.DateTimeField('date published')

In this example, the Blog class is defined as a subclass of models.Model, and contains four attributes
representing fields in the database table. The title and content fields are defined as a CharField and TextField, respectively, while the author field is defined as a ForeignKey to the built-in User
model in Django. The pub_date field is defined as a DateTimeField with a custom verbose name.

By defining models in this way, developers can easily create, read, update, and delete data in the
database using Python code, without having to write SQL queries or interact directly with the database.

19. Which command is used to create a new superuser in Django?

A. python manage.py createsuperuser
B. python manage.py addsuperuser
C. python manage.py newsuperuser
D. python manage.py makesuperuser

Answer: A

To create a superuser, open a terminal or command prompt, navigate to the root directory of your Django project and run the following command: python manage.py createsuperuser.
This will prompt you to enter a username, email address (optional), and password for the new superuser. After creating the superuser, you can use the same credentials to log in to the Django admin interface and access the features that require superuser privileges.

20.What is the purpose of the forms.py file in a Django app?

A. To define URL patterns for the app
B. To define the database schema for the app
C. To define views for the app
D. To define forms for user input

Answer: D

In a Django app, the forms.py file is used to define HTML forms that can be displayed in a web page
and used to collect data from the user.

Django’s form system is built on top of Python classes and provides a convenient way to define forms, handle form validation and error messages, and generate HTML code for rendering the form in a web page. A form class is defined by subclassing django.forms.Form or django.forms.ModelForm, and specifying the fields of the form as class attributes.

For example, the following code defines a simple Django form for collecting user feedback:

from django import forms

class FeedbackForm(forms.Form):
                 name = forms.CharField(label='Your name')
                 email = forms.EmailField(label='Your email address')
                 message = forms.CharField(label='Your feedback', widget=forms.Textarea)

In the above example, the FeedbackForm class is defined as a subclass of forms.Form, and contains
three attributes representing the fields of the form. Each field is defined as an instance of a Django form field class, such as CharField, EmailField, or Textarea.

The label argument is used to specify the label for each form field, which will be displayed in the rendered HTML form. Once a form is defined, it can be used in a Django view function to display the form in a web page and handle the data submitted by the user.

The forms.py file is typically located in the same directory as the app’s models, views, and templates, and is imported by the app’s views and other modules as needed.

21. What is the purpose of the migrations folder in a Django app?

A. To store template files
B. To store database migration files
C. To store static files
D. To store configuration files

Answer: B

The migrations folder contains these migration files, which are named sequentially based on the order they were created. It is an important part of a Django app, as it allows developers to maintain a history of changes to the app’s database schema over time, and to apply these changes to other instances of the app as needed. It also provides a way to version control the database schema, along with the app’s source code, using tools like Git.

22. What is a Django middleware?

A. A component that manages user authentication and authorization
B. A component that handles HTTP requests and responses
C. A component that defines the database schema
D. A component that defines URL patterns

Answer: B

In Django, a middleware is a way to process HTTP requests and responses before they are handled
by the view functions. A middleware is a Python class that defines a set of methods that get called during the request-response cycle. Middleware can modify the request or response, or it can perform other actions, such as logging or authentication.

Django comes with several built-in middleware classes, such as the AuthenticationMiddleware,
which adds the user object to the request if the user is authenticated, and the CsrfViewMiddleware,
which adds protection against cross-site request forgery attacks.

Developers can also create their own custom middleware classes to add additional functionality to the request-response cycle.

23. Which command is used to run the Django test suite?

A. python manage.py test
B. python manage.py runtests
C. python manage.py runtest
D. python manage.py testall

Answer: A

In Django, the python manage.py test command is used to run the test suite for your application. This command will look for any files in your app’s tests directory that start with the prefix test, and run any test functions or classes it finds in those files.

24. What is the purpose of the context parameter in a Django view?

A. To define the database schema
B. To define the behaviour of the view
C. To handle HTTP requests and responses
D. To pass data to the template

Answer: D

In Django, the context parameter in a view is used to pass data from the view to the template. It is
a dictionary-like object that contains key-value pairs of data that will be used in the template to render the HTML response.

The context data can be any kind of Python object, such as a string, number, list, dictionary, or even a custom object. The keys in the context dictionary represent the variable names that will be used in the template, and the values represent the actual data that will be displayed.

For example, if you have a view that displays a list of blog posts, you might pass the list of posts to the template through the context parameter like this:

def blog_post_list(request):
           posts = BlogPost.objects.all()
           context = {'posts': posts}
           return render(request, 'blog/post_list.html', context)

In the above example, the posts variable contains a list of BlogPost objects, and the context
dictionary contains a key-value pair with the key posts and the value posts. This will make the posts
variable available in the post_list.html template using the posts variable name.

The context parameter is an important part of the Model-View-Template (MVT) architecture of Django, as it allows you to separate the logic of your application (the view) from the presentation (the template), and pass data between them in a clean and efficient way.

25. What is the purpose of the STATIC_URL setting in Django?

A. To specify the location of template files
B. To specify the location of static files on the file system
C. To specify the URL prefix for static files
D. To specify the location of media files

Answer: C

The STATIC_URL setting in Django is used to specify the URL from which static files will be
served.

Static files are files like CSS, JavaScript, images, and other types of files that are used by your
application but do not change based on user input. By default, Django looks for static files in a static directory in each installed app and in any additional directories specified in the STATICFILES_DIRS setting.

The STATIC_URL setting is used to specify the base URL for serving static files. For example, if you
set STATIC_URL to /static/, then static files will be served from URLs like

http://yourdomain.com/static/css/styles.css and http://yourdomain.com/static/js/app.js.

26. What is the purpose of the MEDIA_ROOT setting in Django?

A. To specify the URL prefix for media files
B. To specify the location of static files
C. To specify the location of template files
D. To specify the location where uploaded media files are stored

Answer: D

The MEDIA_ROOT setting in Django is used to specify the directory where user-uploaded files
are stored, while the MEDIA_URL setting is used to specify the base URL for serving those files.
In a web application, users may need to upload files such as images, audio, or video files. These files
are typically stored in a separate location from the application code and served separately to the user.

Django provides a built-in FileField and ImageField to handle file uploads, and the MEDIA_ROOT setting is used to specify the directory where these files will be saved. You can also use the MEDIA_URL setting to specify the base URL for serving media files. For example, if you set MEDIA_URL to /media/, then uploaded files will be served from URLs like http://yourdomain.com/media/uploads/myfile.jpg.

It’s important to ensure that the directory specified by MEDIA_ROOT is writeable by the web server.
Also, it’s recommended to store user-uploaded files outside of the application directory for security
reasons.

27. What is the purpose of the MEDIA_URL setting in Django?

A. To specify the URL prefix for media files
B. To specify the location of media files on the file system
C. To specify the location of static files
D. To specify the location of template files

Answer: A

Check the answer to Question-26

28. What is the purpose of the {% url %} template tag in Django?

A. To generate URLs for static files
B. To generate URLs for named URL patterns
C. To generate URLs for media files
D. To generate URLs for database records

Answer: B

The {% url %} template tag is used to dynamically generate URLs for views, allowing you to avoid hard-coding URLs in your templates. When creating a URL pattern in Django, you give it a name that you can use to refer to it from other parts of your code.

For example, you might define a URL pattern like this in your urls.py file:

from django.urls import path 
from . import views

urlpatterns = [ 
path('blog/', views.blog_index, name='blog_index'), 
path('blog//', views.blog_post, name='blog_post'), 
] 

In this example, there are two URL patterns defined: one for the blog index (/blog/), and one for individual blog posts (/blog//). Each pattern is given a unique name using the name parameter.

You can then use the {% url %} template tag in your templates to generate URLs for these views:

<a href="{% url 'blog_index' %}">Blog</a>
<a href="{% url 'blog_post' slug=post.slug %}">{{ post.title }}</a>

In the first example, the {% url 'blog_index' %} template tag generates a URL for the blog_index
view, which is the URL pattern defined earlier for the blog index.

In the second example, the {% url 'blog_post' slug=post.slug %} template tag generates a URL for the blog_post view, passing in the slug parameter for the current blog post.

29. What is the purpose of the {% load %} template tag in Django?

A. To load database records
B. To load static files
C. To load media files
D. To load custom template tags

Answer: D

The {% load %} template tag is used to load a specific template library, which provides additional
functionality for your templates.

Template libraries in Django are modules that contain custom template tags and filters. You can write your own template libraries, or use ones that are provided by third-party packages or Django itself.

By using the {% load %} template tag to load a specific template library, you can add powerful
functionality to your templates and make them more dynamic and flexible.

30. Which of the following is NOT a valid Django model field type?

A. IntegerField
B. FloatField
C. DecimalField
D. MoneyField

Answer: D

Django provides a variety of model field types, which are used to define the structure and data types of fields in your models. Some of the most commonly used model field types include:

• CharField: A field for storing character strings.

• IntegerField: A field for storing integers.

• FloatField: A field for storing floating-point numbers.

• DecimalField: A field for storing decimal numbers with a fixed number of decimal places.

• BooleanField: A field for storing boolean (true/false) values.

• DateField: A field for storing dates (year/month/day).

• DateTimeField: A field for storing dates and times (year/month/day/hour/minute/second).

• TimeField: A field for storing times (hour/minute/second).

• TextField: A field for storing long text strings.

• EmailField: A field for storing email addresses.

• FileField: A field for uploading files.

• ImageField: A field for uploading images.

There are many other Django model field types available, each with their own specific use cases and
options. Additionally, Django also provides a mechanism for creating custom model fields, which
allows the user to define custom data types and validation rules.

31. What is the purpose of the CASCADE parameter in a Django ForeignKey field?

A. To specify what should happen when the referenced object is deleted
B. To specify what should happen when the referencing object is deleted
C. To specify the name of the referenced object
D. To specify the name of the referencing object

Answer: A

A ForeignKey field is used to establish a many-to-one relationship between two models. The purpose of the CASCADE parameter in a ForeignKey field is to specify what should happen to the related object(s) when the object that has the ForeignKey is deleted.

If CASCADE is specified as the on_delete parameter, it means that when the object with the
ForeignKey is deleted, all related objects will also be deleted. This can be useful when you want to
ensure that all related data is removed when the parent object is deleted.

For example, let’s say you have two models: Author and Book. Each Book has a ForeignKey to an
Author, indicating which author wrote the book. If you set the on_delete parameter to CASCADE, it
means that when an Author is deleted, all of their associated books will also be deleted. However, it’s important to use CASCADE with caution, as it can result in the loss of important data. In
many cases, it’s better to use other on_delete options, such as PROTECT (which prevents deletion of
the parent object) or SET_NULL (which sets the ForeignKey to NULL when the parent object is
deleted).

32. Which of the following is a valid Django query filter operator?

A. IN

B. !=

C. LIKE

D. <=

Answer: D

A query filter operator is a keyword used to filter querysets based on specific conditions or criteria. Querysets are used to retrieve objects from the database that match certain conditions, and query filter operators allow you to specify those conditions.

For example, let’s say you have a model called Book with fields like title, author, and published_date. You can use query filter operators to retrieve a subset of books that meet certain criteria.

Some examples of query filter operators in Django include:

• exact: Matches exact value

• iexact: Matches exact value case-insensitively

• contains: Matches value that is contained in another value

• icontains: Matches value that is contained in another value case-insensitively

• gt: Matches values greater than a given value

• gte: Matches values greater than or equal to a given value

• lt: Matches values less than a given value

• lte: Matches values less than or equal to a given value

• in: Matches values that are in a list of values

• startswith: Matches values that start with a given value

• istartswith: Matches values that start with a given value case-insensitively

• endswith: Matches values that end with a given value

• iendswith: Matches values that end with a given value case-insensitively

By using these query filter operators in combination with other queryset methods such as filter(), exclude(), get(), and all(), you can build complex queries to retrieve the data you need from the database.

33. Which of the following is NOT a valid Django queryset method?

A. filter()

B. exclude()

C. update()

D. add()

Answer: D

Django queryset methods are used to query the database and retrieve data. They provide a powerful and flexible way to filter and manipulate data, making it easy to build complex queries without having to write raw SQL.

Some of the most commonly used queryset methods include:

• filter(): This method is used to apply filters to the queryset based on certain conditions. It takes
  one or more keyword arguments, where the keys are the names of the model fields, and the
  values are the conditions to filter on.

• exclude(): This method is used to exclude objects from the queryset based on certain
  conditions. It works similar to the filter() method, but returns a queryset that excludes the
  matching objects.

• order_by(): This method is used to order the queryset based on one or more fields. It takes one
  or more field names as arguments, and can be used to sort the queryset in ascending or
  descending order.

• annotate(): This method is used to annotate the queryset with extra information. It takes one
  or more keyword arguments, where the keys are the names of the new annotations, and the
  values are the expressions used to calculate the annotations.

• values(): This method is used to return a queryset that contains a subset of the fields from the
  model. It takes one or more field names as arguments, and returns a queryset that contains only
  those fields.

• distinct(): This method is used to return a queryset that contains distinct values. It works by
  removing duplicates from the queryset based on the specified fields.

Queryset methods can be chained together to create complex queries.

For example: the filter() method can be used to apply filters based on certain conditions, and then the order_by() method can be used to sort the results. Each queryset method returns a new queryset object, which can be further filtered or manipulated using other queryset methods or Python code.

34. Which of the following is a NOT valid Django model method?

A. delete()
B. fix()
C. all()
D. get()

Answer: B

Django model methods are a way to encapsulate business logic within the models themselves. This
approach helps to keep the code organized, maintainable, and reusable. By defining methods directly on the model class, developers can create reusable building blocks that can be used across the application. A Django model method can perform a wide range of tasks, depending on the needs of the application.

Here are some common examples:

• Data validation: A model method can be used to validate data before it is saved to the database. For example, if a model represents a user profile, a method can be defined to ensure that the email address is in a valid format.

• Data manipulation: A model method can be used to perform calculations or other operations
  on the data stored in the model. For example, a method could be defined to calculate the total
  price of an order based on the quantity and unit price.

• Data retrieval: A model method can be used to retrieve data from the database or to perform
  queries on related models. For example, a method could be defined to retrieve all the orders
  placed by a particular user.

• Custom serialization: A model method can be used to serialize the data in a custom format.
  For example, a method could be defined to return a JSON representation of the model that
  includes only selected fields

Overall, model methods are a powerful tool for adding custom functionality to Django models. By
defining methods within the model class, developers can keep the code organized and make it easier to maintain and modify over time.

Here are some commonly used Django model methods:

• save(): Saves the object to the database.

• delete(): Deletes the object from the database.

• update(): Updates one or more fields on the object and saves it to the database.

• get_or_create(): Gets an object from the database or creates it if it doesn’t exist.

• filter(): Returns a QuerySet of objects that match the given filter criteria.

• exclude(): Returns a QuerySet of objects that don’t match the given filter criteria.

• all(): Returns a QuerySet of all objects in the model’s database table.

• order_by(): Returns a QuerySet of objects ordered by the specified field(s).

• count(): Returns the number of objects in the QuerySet.

• first(): Returns the first object in the QuerySet, or None if the QuerySet is empty.

• last(): Returns the last object in the QuerySet, or None if the QuerySet is empty.

• exists(): Returns True if the QuerySet contains at least one object, False otherwise.

• values(): Returns a QuerySet of dictionaries, each containing the values of the specified fields
  for each object.

• annotate(): Adds an aggregate value to each object in the QuerySet.

• aggregate(): Returns a dictionary containing the values of the specified aggregate functions for
  the QuerySet.

Difference between queryset method and model method:

In Django, a queryset method is a method that is called on a queryset object returned by the ORM
after a query has been made to the database. These methods allow for further filtering, ordering, and manipulation of the data retrieved from the database.

On the other hand, a model method is a method that is defined on the model class itself, and can be
called on any instance of that model. These methods can be used to perform various operations on the model instance, such as generating a URL based on the model’s attributes, or returning a formatted string representation of the model’s data.

The main difference between the two is that queryset methods are used to manipulate the data at
the database level, while model methods are used to manipulate the data at the object level.

Queryset methods are used to construct a queryset that will be used to retrieve data from the database, while model methods are used to manipulate the data once it has been retrieved.
Another key difference is that queryset methods return a new queryset that can be further manipulated, while model methods typically return a value or perform a side effect on the model instance.

35. What is the purpose of the messages framework in Django?

A. To display success and error messages to the user

B. To manage user authentication and authorization

C. To handle HTTP requests and responses

D. To define the database schema

Answer: A

The messages framework is a built-in feature of Django that provides a way for applications to
store messages that can be displayed to users. The purpose of the messages framework is to simplify the process of communicating with users by providing a standard way to display messages.
The messages framework consists of a middleware component that intercepts requests and responses, as well as a set of functions and classes that allow messages to be created and stored in a request. The messages can be of different levels such as success, info, warning, and error, and can be displayed to the user in different ways, such as in the HTML template or in the next request using the redirect() function.

The messages framework is often used in conjunction with form validation, where messages are
displayed to the user indicating any errors or problems with the submitted data. It can also be used for other types of notifications, such as success messages after a user has completed a task.

Overall, the messages framework is a powerful tool that simplifies the process of displaying messages to users and helps ensure that users are kept informed of important information while using a Django application.

36. What is the purpose of the sessions framework in Django?

A. To handle HTTP requests and responses
B. To manage user authentication and authorization
C. To store user session data
D. To define the database schema

Answer: C

The sessions framework in Django is used to manage user sessions. A session is a mechanism used
to store and retrieve data between HTTP requests. It allows a user to carry information from one request to another, for example, storing user login information so that the user doesn’t have to log in again for subsequent requests.

The sessions framework in Django provides a simple way to store and retrieve session data. It stores
session data in a backend, which can be a database, cache, or file system. The sessions framework uses a session ID to identify a user’s session, which is typically stored in a cookie on the user’s browser.

With the sessions framework, you can set and get values stored in the session, as well as delete or clear the entire session. You can also set the expiration time of a session, and manage the session cookie settings. Additionally, the sessions framework provides a middleware that integrates sessions with the Django authentication system, so you can easily manage user sessions in your web application.

37. What is the purpose of the cache framework in Django?

A. To manage user authentication and authorization
B. To cache expensive operations for improved performance
C. To handle HTTP requests and responses
D. To define the database schema

Answer: B

The cache framework in Django provides a way to store and retrieve data quickly by caching it
in memory, on disk, or on a remote cache. Caching is useful for storing data that is expensive to
compute or fetch from a database and is frequently accessed. By caching the data, subsequent requests for the same data can be served quickly without the need for additional computation or database access.

The cache framework provides a simple API for setting, getting, and deleting cached data. It also
supports expiration of cached data, so that stale data is automatically removed and new data is fetched and cached.

The cache framework in Django supports a variety of cache backends, including in-memory caching,
file-based caching, and remote caching using memcached or Redis. The choice of backend depends on the specific use case and the performance requirements of the application.

38. Which of the following is a valid Django middleware class?

A. AuthenticationMiddleware
B. DatabaseMiddleware
C. URLMiddleware
D. MediaMiddleware

Answer: A

Django middleware classes are a way to add custom hooks for processing request/response objects in Django. Middleware classes are essentially Python classes that define methods to be executed before and/or after a view is processed. Middleware can be used to perform a wide range of tasks, such as authentication, caching, logging, and more.

Django comes with several built-in middleware classes that provide various functionality out of the
box, such as:

• AuthenticationMiddleware: Provides a way to authenticate users by setting the user attribute
  on the request object.

• SessionMiddleware: Provides support for Django’s session framework, which allows data to
  be persisted across requests for a given user.

• CsrfViewMiddleware: Provides protection against cross-site request forgery (CSRF) attacks
  by adding a CSRF token to forms and verifying it on POST requests.

• MessageMiddleware: Provides support for Django’s messages framework, which allows
  messages to be passed between views and templates.

• CommonMiddleware: Provides various common HTTP middleware features such as content
  type sniffing, ETag support, and more.

Developers can also create their own middleware classes to add custom functionality to their Django
applications.

39. Which of the following is a valid Django template engine supported by Django?

A. Jinja2
B. Mako
C. Django Templates
D. All of the above

Answer: D

A template engine is a part of the framework that allows developers to generate HTML pages
dynamically by combining data with templates. The Django template engine is responsible for rendering views by processing templates and replacing placeholders in the template with actual data.

Django’s template engine has its own syntax that allows for easy manipulation of data within the
templates. It provides various template tags and filters that enable developers to perform operations on data, such as loops, conditionals, and filtering.

The template engine is designed to be highly extensible, allowing developers to create their own custom tags and filters. Additionally, the Django framework supports multiple template engines, including Django’s built-in template engine, Jinja2, and Mako.

Overall, the template engine is an important component of Django, providing a flexible and powerful
way to generate dynamic HTML pages from data.

40. What is the purpose of the {% extends %} template tag in Django?

A. To specify a parent template to inherit from
B. To specify a child template to include
C. To include static files in the template
D. To include media files in the template

Answer: A

The {% extends %} template tag is used for template inheritance. It allows you to define a base
template that can be extended by other templates. The base template can contain common markup that is shared among all the pages of your website, while the child templates can override specific sections of the base template or add new content to it.

The {% extends %} tag is used at the beginning of a child template and specifies the name of the
parent template that it extends. Once a child template extends a parent template, it inherits all the
blocks and content of the parent template. The child template can override any block by defining it
with the same name, or it can add new blocks to the parent template using the {% block %} tag.

Template inheritance is a powerful feature of the Django template engine that allows you to reuse code and keep your templates DRY (Don’t Repeat Yourself). By defining a base template with common markup and extending it in your child templates, you can save a lot of time and reduce the amount of code duplication in your templates.

41. What is the purpose of the {% block %} template tag in Django?

A. To define a block of content that can be overridden in child templates
B. To define a block of content that cannot be overridden in child templates
C. To define a block of content that can be overridden in child templates
D. To define a block of content that should never be included in the template

Answer: C

Check the answer to Question-40

42. What is the purpose of the {% include %} template tag in Django?

A. To include a static file in the current template
B. To include another template in the current template
C. To include a media file in the current template
D. To include a database record in the current template

Answer: B

The {% include %} template tag in Django is used to include the contents of another template within the current template. This is useful for reusing common elements or components across multiple templates without duplicating the code.

The syntax for the {% include %} tag is as follows:

{% include "path/to/template.html" %}

Here, path/to/template.html is the relative path to the template file that you want to include.
You can also pass context data to the included template using the with keyword:

{% include "path/to/template.html" with some_variable=value %}

In this example, some_variable is a variable name that will be available within the included template
with the value value.

43. What is the purpose of the {% if %} template tag in Django?

A. To define a loop in the template
B. To conditionally display content in the template
C. To define a block of content that can be overridden in child templates
D. To define a block of content that cannot be overridden in child templates

Answer: B

The {% if %} template tag is used to conditionally render content in a template. It evaluates a condition and, if it is true, includes the content inside the tag. If the condition is false, the content is not included.

The basic syntax for {% if %} tag is:

{% if condition %}
            <!-- content to display if condition is true -->
{% else %}
            <!-- content to display if condition is false -->
{% endif %}

Here, condition is any expression that can be evaluated as true or false, such as a boolean value, a comparison, or a logical operator. The {% if %} tag can also be nested to create more complex conditions.

Additionally, it can be used in conjunction with other template tags, such as {% for %} and {% block %}, to create more dynamic templates.

44. What is the purpose of the {% for %} template tag in Django?

A. To define a block of content that can be overridden in child templates
B. To conditionally display content in the template
C. To define a loop in the template
D. To define a block of content that cannot be overridden in child templates

Answer: C

The {% for %} template tag in Django is used to iterate over a collection of elements and render the contents of the block for each item in the collection. It takes an iterable object as an argument and provides access to each element in the collection through a loop variable.

For example, if we have a list of blog posts in our context, we can use the {% for %} tag to iterate over the list and display the title of each post:

{% for post in posts %}
    <h2>{{ post.title }}</h2>
{% endfor %}

In this example, posts is the iterable object, and post is the loop variable that we use to access each element in the collection. The block between {% for %} and {% endfor %} is repeated for each item in the collection. Inside the block, we use {{ post.title }} to access the title attribute of the current post object in the loop.

45. What is the purpose of the {% url %} template tag in Django?

A. To generate a URL for a named URL pattern
B. To include a static file in the current template
C. To include a media file in the current template
D. To include a database record in the current template

Answer: A

The {% url %} template tag in Django is used to generate URLs for named URL patterns defined in
the project’s URL configuration. It takes one or more arguments that specify the name of the URL
pattern and any additional parameters required to generate the URL.

For example, suppose you have a named URL pattern in your project’s URL configuration called
myapp:view, and you want to generate a URL to that view with a parameter id=1. You can use the
following {% url %} tag:

{% url 'myapp:view' id=1 %}

This will generate the URL /myapp/view/1/ if your URL pattern is configured to expect an id
parameter. Using the {% url %} template tag makes it easy to maintain consistency in URLs throughout a project, since you only need to change the URL pattern definition in one place if you need to update it.

46. What is the purpose of the {% csrf_token %} template tag in Django?

A. To include a database record in the current template
B. To include a static file in the current template
C. To include a media file in the current template
D. To include a CSRF token in a form

Answer: D

The {% csrf_token %} template tag in Django is used to include a CSRF token in a form.

CSRF stands for Cross-Site Request Forgery, which is an attack where a malicious website tricks a user into performing an action on another website without their knowledge or consent.

To prevent this type of attack, Django includes a built-in CSRF protection mechanism. When a form is submitted in Django, the {% csrf_token %} tag ensures that the form data includes a CSRF token.

This token is generated by Django and is specific to the user’s session, so it cannot be guessed by an attacker. When the form is submitted, the CSRF token is verified by Django to ensure that it matches the expected value for that user’s session. The {% csrf_token %} tag should be included in all forms that submit data to a Django view. To use it in a template, simply include {% csrf_token %} inside the <form> tag. For example

<form method="post">
      {% csrf_token %}
      <!-- form fields go here -->
</form>

By including the {% csrf_token %} tag in your form, you can help protect your Django application
from CSRF attacks.

47. Which of the following is NOT a valid Django view function parameter?

A. request
B. user
C. template_name
D. pk

Answer: B

Django view functions are responsible for handling incoming HTTP requests and generating HTTP
responses. They accept various parameters, including:

• request: This is the first parameter of any view function in Django. It represents the incoming HTTP request and contains information about the user’s request, such as the requested URL, headers, and body.

• *args and **kwargs: These are optional parameters that allow you to capture any additional arguments passed to the view function. *args captures positional arguments as a tuple, while **kwargs captures keyword arguments as a dictionary.

• Form data: If the view function is handling a POST request, the form data can be accessed
  through the request POST dictionary-like object.

• Session data: If your application uses Django’s session framework, you can access the session data using the request.session dictionary-like object.

• Query parameters: Query parameters are parameters passed in the URL after a question mark
  (?). They can be accessed using the request.GET dictionary-like object.

• Template context variables: You can pass any data that you want to make available to the template as a dictionary using the context parameter. The keys of the dictionary represent the variable names that are available in the template, while the values represent the values of those variables.

• URL parameters: If you define a URL pattern with parameters, the view function can accept these parameters as arguments. For example, if you define a URL pattern like path (blog//, views.blog_post_detail), the post_id parameter can be passed to the blog_post_detail view function.

48. Which of the following is NOT a valid Django form field type?

A. CharField
B. IntegerField
C. DecimalField
D. ImageField

Answer: D

Django form field types are classes that define the type of input a user can enter in a form. Some of the commonly used Django form field types are:

• CharField: It is used to take in a single line of text input.
• IntegerField: It is used to take in integer input.
• FloatField: It is used to take in floating-point number input.
• DecimalField: It is used to take in decimal number input.
• EmailField: It is used to take in email input.
• URLField: It is used to take in URL input.
• BooleanField: It is used to take in boolean (True or False) input.
• DateField: It is used to take in date input.
• DateTimeField: It is used to take in date and time input.
• TimeField: It is used to take in time input.

49. What is the purpose of the clean() method in a Django form?

A. To validate and clean submitted form data
B. To define the form fields
C. To specify the form widgets
D. To define the form layout

Answer: A

The clean() method is a built-in method in Django forms that is used to validate and clean the input
data submitted by a user. It is called by the is_valid() method of the form and is responsible for
cleaning and validating all fields of the form.

The clean() method performs a number of checks on the form data, such as checking if the required fields are present, checking the data format, and checking the data against custom validation rules. It returns the cleaned data in a dictionary format, which can then be used to update the form instance or save the data to the database.
If the clean() method detects any errors in the form data, it raises a ValidationError exception with an error message that is associated with the relevant field. These error messages can then be displayed in the form to help the user correct their input.

50. What is the purpose of the django.db.models.Model class in Django?

A. To define views in Django
B. To define database models in Django
C. To define URL patterns in Django
D. To define forms in Django

Answer: B

The django.db.models.Model class is the base class for all Django models. It is a Python class that
provides a way to define the structure and behaviour of database models.

The django.db.models.Model class provides a lot of functionality out of the box, such as database
field types (e.g. CharField, IntegerField, DateField, etc.), default values for fields, relationships
between models (e.g. ForeignKey, ManyToManyField, etc.), and database table management (e.g.
creating and updating tables). By using this class, you can easily create database tables and interact
with them using Python code.

51. What is the purpose of the django.contrib.admin module in Django?

A. To provide a web-based administration interface for Django projects
B. To provide authentication and authorization features for Django projects
C. To provide integration with third-party authentication providers for Django projects
D. To provide tools for testing Django projects

Answer: A

The django.contrib.admin module is a built-in Django application that provides a web-based
administrative interface for managing Django models. It allows users with the appropriate
permissions to add, edit, and delete model instances through a user-friendly interface, without requiring knowledge of SQL or programming.

It also :

• provides default templates and views for rendering and interacting with models.

• can be customized to meet the needs of a specific application by defining custom admin classes that inherit from django.contrib.admin.ModelAdmin and override its default behavior.

• is included in Django by default, but it can be removed or disabled if not needed.

• can also be extended with third-party packages or customizations to add additional functionality
  or custom views.

52. What is the purpose of the django.contrib.auth module in Django?

A. To provide a web-based administration interface for Django projects
B. To provide authentication and authorization features for Django projects
C. To provide integration with third-party authentication providers for Django projects
D. To provide tools for testing Django projects

Answer: B

The django.contrib.auth module provides a built-in authentication system that handles user
accounts, groups, permissions, and password management. It provides models for user accounts and groups, views for user authentication, and forms for handling user input. This module provides an easy way to integrate authentication into a Django web application without having to write custom code for user management.

It also provides various authentication backends for authentication via username/password, email/password, or external services such as OAuth.

53. What is the purpose of the django.contrib.staticfiles module in Django?

A. To provide a web-based administration interface for Django projects
B. To serve media files like images and videos in Django projects
C. To serve static files like CSS and JavaScript in Django projects
D. To provide authentication and authorization features for Django projects

Answer: C

The django.contrib.staticfiles module in Django is responsible for managing static files for a project. Static files are files like CSS, JavaScript, images, and fonts that do not change dynamically and are served to the client as they are.

54. What is the purpose of the django.forms.ModelForm class in Django?

A. To define a form independent of any model in Django
B. To define a form based on a model in Django
C. To define a view in Django
D. To define a URL pattern in Django

Answer: B

The django.forms.ModelForm class is a subclass of django.forms.Form that can be used to create
a form based on a Django model. This class automatically generates form fields from the model fields and provides additional features like model instance saving.

By subclassing ModelForm, you can quickly create a form that corresponds to a model in your database. You don’t need to define form fields manually – they are generated based on the fields in the model. This can save a lot of time and reduce errors when creating forms.

The ModelForm class also provides a save() method that can be used to save a form instance as a
new model instance or update an existing one. This method takes care of creating or updating the model instance based on the data in the form.

Overall, the ModelForm class provides a convenient way to create forms based on Django models
and makes it easier to work with model instances in views and templates.

55. What is the purpose of the django.core.validators module in Django?

A. To provide a set of built-in validators for Django forms and models
B. To provide a set of built-in validators for Django queries
C. To provide a set of built-in middleware for Django projects
D. To provide a set of built-in validators for Django views

Answer: A

The django.core.validators module provides a set of built-in validation functions that can be used to validate form fields and model fields. These validators can be used to validate the user input to ensure that it meets certain criteria or constraints.

Some of the commonly used validators in the django.core.validators module are:

• MinValueValidator and MaxValueValidator: These validators are used to validate numeric
  values and ensure that they are within a specified range.

• EmailValidator: This validator is used to validate email addresses to ensure that they are in a
  valid format.

• RegexValidator: This validator is used to validate input against a regular expression pattern.

• URLValidator: This validator is used to validate URLs to ensure that they are in a valid format.

• FileExtensionValidator: This validator is used to validate file extensions to ensure that they
  match a specified list of extensions.

Validators can be used in both forms and models in Django. In forms, validators are used to validate
user input before it is saved to the database, while in models, validators are used to validate model fields before they are saved to the database.

56. What is the purpose of the reverse function in the django.urls module?

A. To convert a string to lowercase
B. To generate a URL for a non-named URL pattern
C. To reverse the order of the characters in a string
D. To generate a URL for a named URL pattern

Answer: D

The reverse() function in the django.urls module is used to generate a URL string that matches a
given view function or named URL pattern. The function takes the view function name or the named
URL pattern as the argument and returns the corresponding URL.

For example, if you have a view function named my_view that is mapped to the URL pattern myurl/ in your urls.py file, you can generate the URL string using the reverse() function as follows:

from django.urls import reverse

url = reverse('my_view')

The above code returns: /my-url/.

You can also pass arguments to the URL pattern by including them in the function call:

url = reverse('my_view', args=[1])

This returns: /my-url/1/

57. What is the purpose of the include function in the django.urls module in Django?

A. To include a static file in the current template

B. To include other URL patterns in the current URL pattern

C. To include a media file in the current template

D. To include a database record in the current template

Answer: B

The include() function from django.urls is used to include other URL patterns in the URL
configuration of a Django project. It allows for organizing the URL patterns of a project into modular,
reusable components.

For example, if you have a separate app within your project that handles user authentication, you can define the URLs for that app in its own urls.py file and include them in the project’s main urls.py file using include(). This way, the project’s main URL configuration remains uncluttered and easier to maintain.

The include() function takes as its argument the module containing the URL patterns to include. It
can also take an optional namespace argument, which is useful for avoiding naming collisions between different apps in the same project.

58. What is the purpose of the django.shortcuts.render function in Django?

A. To render a template with context data and return an HTTP response
B. To render a form and return an HTTP response
C. To render a model instance and return an HTTP response
D. To render a queryset and return an HTTP response

Answer: A

The render() function in shortcuts module is used to render a Django template with a context
dictionary and return an HTTP response. The purpose of the render() function is to simplify the
process of rendering a template by combining the steps of loading the template, rendering the template with the context data, and returning the HTTP response into a single function call.

The render() function takes the following parameters:

• request: The HTTP request object.
• template_name: The name of the template to be rendered.
• context: A dictionary containing the context data to be used when rendering the template.
• content_type: The MIME type of the response content. By default, the content type is
  “text/html”.
• status: The HTTP status code for the response. By default, the status code is 200 (OK).
• using: The name of the database connection to use for the view. By default, the default
  database connection is used.

The render() function loads the specified template and renders it with the provided context dictionary.

The resulting output is then used to create an HTTP response, which is returned to the client.

For example:

from django.shortcuts import render

def my_view(request):
            my_var = "Hello, world!"
            context = {'my_var': my_var}
            return render(request, 'my_template.html', context)

In the above example, the my_view() uses the render function to render my_template.html with a
context dictionary containing a variable named my_var. The resulting output is returned to the client
as an HTTP response.

59. What is the purpose of the django.test.TestCase class in Django?

A. To define a view in Django
B. To define a model in Django
C. To provide tools for testing Django projects
D. To define a form in Django

Answer: C

django.test.TestCase class is a powerful tool for testing Django applications, providing a number of features that make it easy to write comprehensive and reliable tests.

It is a subclass of the built-in Python unittest.TestCase class that provides some additional features for testing Django applications. It sets up a test database and provides a number of helper methods for testing Django-specific functionality.

When tests are run with django.test.TestCase, a new database is created for the tests to run in, and then destroyed when the tests are finished. This ensures that tests do not interfere with each other, and that the database is always in a known state at the beginning of each test.

Some of the features provided by django.test.TestCase include:

• A setUpTestData() method that is run once before any tests in the test case are run, and can
  be used to set up test data that will be shared between all tests in the test case.
• A setUp() method that is run before each test, and can be used to set up any test-specific data
  or resources.
• A tearDown() method that is run after each test, and can be used to clean up any resources
  that were set up in setUp().
• A number of assertion methods that are specific to Django, such as assertQuerysetEqual()
  for comparing querysets, and assertContains() for checking that a response contains a
  particular piece of content.

60. What is the purpose of the Meta class in a Django model?

A. To define the fields of the model
B. To customize the behaviour of the model
C. To define the order in which model instances are displayed in the admin interface
D. To define the permissions for the model

Answer: B

The Meta class allows you to customize the behaviour of your model in various ways, providing you
with more control over how your data is stored and retrieved from the database. It allows you to set
various options such as the database table name, ordering of results, indexes, and more.

The Meta class is declared inside a model class and its options are defined as class attributes.

For example:

from django.db import models

class MyModel(models.Model):
       # fields go here
       class Meta:
             db_table = 'my_table'
             ordering = ['-created_at']

In the above example, the Meta class is used to set the name of the database table to my_table, and to specify that results should be ordered by the “created_at” field in descending order.

Other options that can be set using the Meta class include:

• verbose_name: The human-readable name of the model. By default, Django will use the class
  name with spaces added between words (e.g. “My Model” for a class named MyModel).
• verbose_name_plural: The plural form of the verbose_name.
• unique_together: A list of tuples specifying fields that should be unique together.
• indexes: A list of fields to create database indexes for.
• constraints: A list of constraints to apply to the table, such as unique or foreign key
  constraints.

61. What is the purpose of the related_name attribute in a Django model field?

A. To define the name of the related model
B. To define the name of the reverse relation from the related model
C. To define the name of the foreign key field in the related model
D. To define the name of the primary key field in the related model

Answer: B

The related_name attribute is used in Django model fields to specify the name of the reverse
relation from the related object back to the current object. It is only used when defining a
ForeignKey, OneToOneField, or ManyToManyField in a Django model.

For example:

class Person(models.Model):
       name = models.CharField(max_length=50)
class Book(models.Model):
       title = models.CharField(max_length=50)
       author = models.ForeignKey(Person, on_delete=models.CASCADE, related_name='books')

In the above example, the related_name='books' attribute specifies that the Person model should
have a reverse relation named books that returns all Book objects that have the current Person
object as their author. This allows us to access all books by a given author using the books attribute
of a Person object:

>>> person = Person.objects.get(name='John')
>>> books = person.books.all()

Note that if the related_name attribute is not specified, Django will automatically generate a default
name for the reverse relation, which is the lowercase name of the model followed by _set. In the above example, the default related_name would be book_set, and we would access the books by a given author using the book_set attribute of a Person object:

>>> person = Person.objects.get(name='John')
>>> books = person.book_set.all()

62. What is the difference between a OneToOneField and a ForeignKey in Django?

A. A OneToOneField creates a unique relationship between two models, while a ForeignKey creates a
many-to-one relationship between two models
B. A OneToOneField creates a many-to-one relationship between two models, while a ForeignKey
creates a unique relationship between two models
C. A OneToOneField is a shortcut for creating a unique ForeignKey and a related OneToOneField on
the related model, while a ForeignKey is a standard field for creating a many-to-one relationship
between two models
D. A OneToOneField is a shortcut for creating a many-to-one ForeignKey and a related OneToOneField on the related model, while a ForeignKey is a standard field for creating a unique relationship between two models

Answer: A

ForeignKey is used when a model has multiple instances of another model, while OneToOneField
is used when a model has only one instance of another model.

For example:

Customer model could have multiple Order instances, but each Order can only be associated with one Customer. In this case, you would create a ForeignKey field in the Order model that points to the Customer model.

Whereas: Person model could have one Passport instance, and each Passport can be associated with only one Person.

In this case, you would create a OneToOneField field in the Person model that points to the Passport model.

63. What is the purpose of the on_delete attribute in a ForeignKey field in Django?

A. To specify the related model for the field
B. To specify the name of the field on the related model
C. To specify the behaviour when the related object is deleted
D. To specify the behaviour when the field is null

Answer: C

The on_delete attribute in a ForeignKey field specifies what should happen when the referenced object is deleted. It is a required argument because the default behaviour in case of deletion is undefined and can cause referential integrity problems.

The on_delete attribute can take one of the following values:

• CASCADE: When the referenced object is deleted, delete the objects that have a ForeignKey
  to it.
• PROTECT: Prevent deletion of the referenced object by raising a ProtectedError.
• SET_NULL: Set the foreign key to NULL on deletion of the referenced object.
• SET_DEFAULT: Set the foreign key to its default value on deletion of the referenced object.
• SET(): Set the foreign key to the value passed to SET() on deletion of the referenced object.
• DO_NOTHING: Do nothing and rely on database referential integrity.

64. What is the purpose of the unique_together attribute in a Django model?

A. To ensure that the combination of values for a set of fields is unique
B. To ensure that the values for a field are unique across all instances of the model
C. To ensure that the values for a field are unique within a related model
D. To ensure that the values for a set of fields are unique within a related model

Answer: A

The unique_together attribute in a Django model is used to define constraints that specify one or more sets of fields that must have a unique combination of values. This attribute is defined as a list of tuples, where each tuple specifies the fields that should be unique together.

For example, consider a Person model with first_name, last_name, and email fields. We may want to ensure that no two people in the database have the same combination of first_name and last_name, or the same email. We can define the unique_together attribute in the Meta class of the model as follows:

class Person(models.Model):
      first_name = models.CharField(max_length=30)
      last_name = models.CharField(max_length=30)
      email = models.EmailField()

 class Meta:
      unique_together = (('first_name', 'last_name'), ('email',))

In the above example, we have specified that the combination of first_name and last_name should
be unique together, as well as the email field. If a user tries to save a Person instance with a combination of values that violates one of the unique_together constraints, it will raise a ValidationError.

65. What is the purpose of the db_column attribute in a Django model field?

A. To specify the constraints on the field in the database
B. To specify the type of the field in the database
C. To specify the default value of the field in the database
D. To specify the name of the field in the database

Answer: D

The db_column attribute in Django model field is used to specify the name of the database column that corresponds to the field. By default, Django generates a database column name by converting the field name to lower case and adding an underscore between words. However, sometimes it may be necessary to override this behavior and specify a custom name for the database column.

For example, consider a model with a field named first_name. By default, Django will generate a
database column name of first_name. However, if you wanted to use a different name for the database column, such as fname, you could set the db_column attribute to fname:

class MyModel(models.Model):
          first_name = models.CharField(max_length=50, db_column='fname')

This would cause Django to use fname as the name of the database column for the first_name field

66. What is the purpose of the db_index attribute in a Django model field?

A. To specify the constraints on the field in the database
B. To specify the type of the field in the database
C. To specify the default value of the field in the database
D. To create an index on the field in the database

Answer: D

The db_index attribute in model fields is used to specify whether an index should be created on the
database column associated with the field.

An index can improve the performance of database queries that involve the field by allowing the database to find and retrieve the relevant rows more quickly. By default, Django creates indexes for all fields that have a relationship with another model (e.g., ForeignKey, OneToOneField, ManyToManyField), and for fields that are used in queries frequently. However, you can also manually specify the db_index attribute on a field to create an index for that field, even if it doesn’t meet the default criteria for index creation.

For example, consider a model with a name field that is frequently used in queries, this is how you
can add an index to it:

class MyModel(models.Model):
        name = models.CharField(max_length=50, db_index=True)

This index will be created on the name database column to improve query performance. However, it’s
important to note that creating indexes can also have downsides, such as increased storage requirements and slower write performance, so you should only create indexes on fields that are truly necessary.

67. What is the purpose of the abstract attribute in a Django model?

A. To indicate that the model is abstract and should not be created as a database table
B. To indicate that the model is concrete and should be created as a database table
C. To indicate that the model is a child of an abstract model and should not be created as a database table
D. To indicate that the model is a child of a concrete model

Answer: A

The abstract attribute in a model is used to create an abstract base class for other models to inherit
from, without creating a table in the database for the abstract model itself.

When a model has abstract=True in its Meta class, Django will not create a table for that model when running migrations. Instead, it will serve as a template for other models to inherit from, providing common fields and methods that can be reused across multiple models.

By using abstract models, developers can avoid duplicating code and can easily create related models with common fields, methods, and behaviors. Abstract models can be used to define common fields,methods, or behavior for a group of models that share common characteristics.

68. What is caching?

A. Caching is the process of storing data in a temporary location to improve performance
B. Caching is the process of permanently storing data in a database
C. Caching is the process of storing data in a separate server for backup purposes
D. Caching is the process of encrypting data for security purposes

Answer: A

Caching is the process of locally storing frequently accessed data in memory or on disk so that it can be quickly retrieved the next time it is needed. Caching is used to improve the performance of web applications by reducing the number of database queries and expensive computations that are needed to generate a response.

Django provides a built-in caching framework that supports various caching backends, including memory-based caching, file-based caching, and distributed caching using tools like Redis or Memcached.

To use caching you can define a cache object in your settings file and then use the cache object to store and retrieve data in your views or other parts of your application. For example, you can cache the results of a database query or the output of a computationally expensive function so that they can be quickly retrieved the next time they are needed.

Django also provides cache middleware that can be used to automatically cache the entire response for a view, so that subsequent requests can be served directly from the cache without having to execute the view code again. This can be a powerful way to improve the performance of your application for frequently accessed pages.

69. What are the different types of caching supported by Django?

A. In-memory caching, file-based caching, database caching, and network caching
B. In-memory caching, file-based caching, and database caching
C. In-memory caching, file-based caching, and network caching
D. In-memory caching, database caching, and network caching

Answer: B

Django supports these types of commonly used caching:

• Memory caching: This type of caching stores the cache data in the memory of the web server.
  It is the fastest type of caching but has a drawback that the cache data is lost when the server is
  restarted or the cache is cleared.

• File-based caching: This type of caching stores the cache data in a file on the file system. It is slower than memory caching but is persistent even after the server is restarted.

• Database caching: This type of caching stores the cache data in a database. It is slower than
  memory and file-based caching but provides persistence and scalability.

• Cache backend chaining: This involves using multiple cache backends in a chain. For example, a combination of memory caching and file-based caching can be used to get the best of both worlds. The data is first stored in memory cache, and if it is not available there, it is retrieved from the file-based cache.

Django also supports several third-party caching solutions like Memcached and Redis that can be used as cache backends.

70. How can you enable caching in Django views?

A. By adding the @cache decorator to the view function
B. By adding the @cache_page decorator to the view function
C. By setting the CACHE_MIDDLEWARE_ALIAS setting to default in the settings file
D. By setting the CACHE_MIDDLEWARE_SECONDS setting to a non-zero value in the settings file

Answer: B

Caching in views can be enabled using the cache_page decorator provided by the django.views.decorators.cache module.

The cache_page decorator can be used to cache the output of a view for a specified amount of time.

For example, the following code will cache the output of a view for 5 minutes:

from django.views.decorators.cache import cache_page

@cache_page(300)
def my_view(request):
         # view code here

In the above example, the cache_page decorator takes a single argument, which specifies the number of seconds to cache the response. In this case, the view response will be cached for 300 seconds (5 minutes).

You can also use the cache_control decorator provided by the django.views.decorators.cache
module to control caching on a per-view basis. This decorator allows you to set the HTTP headers used for caching, such as Cache-Control and Expires.

Additionally, you can use the Django caching framework to cache the results of more complex operations, such as database queries or expensive computations. This can be done using the cache object provided by the django.core.cache module.

71. What is the purpose of the cache_page decorator in Django?

A. It caches the entire page in memory for a specified amount of time
B. It caches the page template in memory for a specified amount of time
C. It caches the page content in a file on disk for a specified amount of time
D. It caches the page content in a separate database table for a specified amount of time

Answer: A

Check the answer to Question-70

72. How do you use Django’s cache API to store and retrieve data?

A. By calling the cache.get(key) and cache.add(key, value) methods
B. By calling the cache.retrieve(key) and cache.store(key, value) methods
C. By calling the cache.get(key) and cache.set(key, value) methods
D. By calling the cache.retrieve(key) and cache.save(key, value) methods

Answer: C

Django provides a cache API that can be used to store and retrieve data in a cache. The cache can be configured to use different cache backends such as in-memory caching, file-based caching, database caching, or even external caching services like Memcached or Redis.

To store data in the cache, you can use the set() method. The set() method takes two arguments: a cache key and a value.

To retrieve data from the cache, you can use the get() method. The get() method takes one argument: the cache key.

from django.core.cache import cache

To set:

cache.set('greeting', 'Hello, World!')

To get:

greeting = cache.get('greeting')

If the cache key greeting does not exist in the cache, the get() method will return None.

You can also specify a default value to return if the cache key does not exist by passing a second argument to the get() method. For example:

greeting = cache.get('greeting', 'Default greeting')

In this example, if the cache key greeting does not exist in the cache, the get() method will return
the string Default greeting.

73. What is the difference between a cache hit and a cache miss in Django?

A. A cache hit occurs when data is deleted from the cache, while a cache miss occurs when data is not deleted from the cache.
B. A cache hit occurs when data is not found in the cache, while a cache miss occurs when data is found in the cache
C. A cache hit occurs when data is found in the cache, while a cache miss occurs when data is not found in the cache
D. A cache hit occurs when data is modified in the cache, while a cache miss occurs when data is not
modified in the cache

Answer: C

A cache hit occurs when the requested data is found in the cache, and it can be immediately returned without having to perform any further processing or database queries. A cache miss
occurs when the requested data is not found in the cache, and the application needs to perform
additional processing or database queries to generate the required data before storing it in the
cache for future use.

In general, cache hits are desirable as they result in faster response times and reduced load on the
database, while cache misses are less desirable as they can increase response times and result in higher load on the database.

Therefore, the goal of caching is to maximize the number of cache hits and minimize the number of cache misses.

74. What is the purpose of caching in Django?

A. To store frequently accessed data in memory
B. To reduce the load on the database
C. To speed up the application
D. All of the above

Answer: D

The purpose of caching in Django is to improve the performance and speed of web applications by
reducing the number of database queries and expensive computations required to render a
response. Caching stores the results of expensive operations in memory or on disk so that they can
be quickly retrieved and reused in subsequent requests, rather than having to redo the work every
time the same data is needed.

By using caching, Django can serve frequently requested pages faster, improve the overall response
time of the application, and reduce the load on the database and other backend resources. Additionally, caching can help handle sudden spikes in traffic by reducing the load on the server and preventing it from becoming overwhelmed with requests.

75. Which cache backend is recommended for a high-traffic production site?

A. DummyCache
B. MemcachedCache or Redis
C. LocMemCache
D. FileBasedCache

Answer: B

The recommended cache backend for a high-traffic production site depends on various factors, such as the expected traffic volume, the amount of data to be cached, and the available infrastructure.

However, in general, a distributed cache backend such as Memcached or Redis is recommended for hightraffic sites, as they allow for scaling across multiple servers and can handle a large number of
concurrent requests.

These backends can be used in combination with Django’s cache framework, which provides a consistent API for working with different cache backends. It is also recommended to use a cache backend that is well-maintained, reliable, and secure.

76. What is the expiration time for LocMemCache data in Django by default?

A. 10 seconds
B. 60 seconds
C. 300 seconds
D. 600 seconds

Answer: C

The default expiration time for cache data in Django is not defined globally and may vary depending
on the cache backend being used.

Some cache backends, such as the LocMemCache backend, use an expiration time of 300 seconds (5 minutes) by default, while others, such as the Redis cache backend, may have different default expiration times or no default expiration time at all.

In general, it’s a good practice to set an appropriate expiration time for cached data based on how
frequently the data changes and how important it is to have the most up-to-date version of the data. This can help ensure that stale data is not served from the cache for too long and that the cache is not unnecessarily burdened with too much data that is no longer useful.

77. How can you invalidate a specific cache key in Django?

A. Use the delete() method of the cache backend
B. Use the expire() method of the cache backend
C. Use the invalidate() method of the cache backend
D. Use the clear() method of the cache backend

Answer: A

To invalidate a specific cache key you can use the cache.delete() method provided by the cache
API. This method takes a single argument, which is the cache key you want to delete.

For example:

from django.core.cache import cache
 
# Set the cache value
cache.set('my_key', 'my_value')

# Get the cache value
value = cache.get('my_key')

print(value) # Output: 'my_value'

# Invalidate the cache key
cache.delete('my_key')

# Try to get the cache value again
value = cache.get('my_key')
print(value) # Output: None

In the above example, we first set a cache value with the key ‘my_key’. We then retrieve the value using cache.get() and print it to the console.

We then invalidate the cache key using cache.delete('my_key'). Finally, we try to retrieve the cache value again using cache.get() and print the result. Since we have invalidated the cache key, the result is None.

78. Which Django setting specifies the default cache backend to use?

A. CACHE_DEFAULT_BACKEND
B. CACHE_BACKEND
C. CACHE_TYPE
D. CACHE_STORAGE

Answer: B

The CACHE_BACKEND setting in the Django settings file specifies the default cache backend
to use.

79.What is the purpose of cache middleware in Django?

A. To cache the entire response for a view
B. To cache a portion of the request object
C. To cache the request object
D. To cache the response object

Answer: B

The middleware intercepts the response generated by the view and caches it before sending it to the
client. The cache middleware in Django can be configured to cache either the entire response or a portion of the response, depending on how it is implemented. By default, the cache middleware caches the entire response.

However, you can configure it to cache only certain parts of the response, such as the content, headers, or cookies, by setting the appropriate cache_timeout, cache_alias, and
cache_key_prefix options.

In addition, you can use the cache_page decorator to cache the entire view function, or you can use
the low-level cache API to cache specific data at any point in your code.

The purpose of cache middleware is to improve the performance of the application by reducing the
response time for frequently accessed pages. By caching the response, the server can avoid having to regenerate the same response repeatedly for each request.

The cache middleware in Django is highly configurable and supports various options such as setting
the cache timeout, using different cache backends, caching based on the HTTP method, and more.

To enable the cache middleware in a Django project, you need to add it to the MIDDLEWARE setting in your project’s settings.py file. The cache middleware is typically placed near the top of the middleware stack to ensure that it intercepts requests early in the request-response cycle.

80. What is cache versioning in Django?

A. The process of updating the cache backend to a newer version
B. The process of updating the cache keys to a newer version
C. The process of updating the cache data to a newer version
D. The process of changing the cache backend to a newer version

Answer: B

Cache versioning is a technique used in Django to ensure that cached data is not used when it becomes invalid. It involves adding a version number to the cache key used to store data, so that when the version number changes, the cache key is invalidated and new data is stored in the cache with the updated key.

In Django, cache versioning can be implemented using the cache.add() method, which allows you to specify a version number in addition to the cache key and the data to be stored. For example:

from django.core.cache import cache

# Set the cache version number
CACHE_VERSION = 1

# Define the cache key
CACHE_KEY = 'my_data'

# Get the data from the cache
data = cache.get(f'{CACHE_KEY}_{CACHE_VERSION}')

# If the data is not in the cache, generate it and store it
if data is None:
       data = generate_data()
       cache.add(f'{CACHE_KEY}_{CACHE_VERSION}', data)

In the above example, the cache key includes the version number CACHE_VERSION in addition to
the data identifier CACHE_KEY. If the version number changes, the cache key is invalidated and new
data is stored in the cache with the updated key. This ensures that stale data is not used when the data structure or logic changes, which can be particularly important in applications with frequently changing data.

81. What happens if the cache backend is unavailable in Django?

A. A warning message is displayed in the log file
B. A new cache backend is automatically created
C. The application crashes
D. The cache is disabled and the data is retrieved from the database

Answer: D

If the cache backend is unavailable in Django, requests to the cache will fail and the application will
continue to function as normal. However, any cached data will not be available, and the application
will need to fetch the data from the database or generate it dynamically, which can result in slower
response times. To avoid this, it is recommended to have a backup cache or fallback option, such as
using a different cache backend or storing data in a local cache. Additionally, it is important to monitor the cache and address any issues as soon as possible to ensure optimal performance of the application.

82. What is a Model in Django ORM?

A. A database table
B. A database view
C. A Python class
D. A database field

Answer: C

A model in Django ORM (Object-Relational Mapping) is a Python class that represents a database table or collection. It allows developers to interact with the database using high-level Python methods, rather than writing raw SQL queries.

A model defines the fields and behaviours of the data stored in the database, such as what data types can be stored, how data is validated, and how data is related to other models. Models are defined in the models.py file of a Django app and are subclassed from the django.db.models.Model class.

83. Which of the following is NOT a valid field type in Django ORM?

A. IntegerField
B. CharField
C. DateTimeField
D. BitField

Answer: D

Fields in Django ORM are used to define the type of data that can be stored in a database table. Django provides various built-in field types, some of which are:

• CharField: Used to store short text strings (e.g. names, titles).
• TextField: Used to store long text strings (e.g. descriptions, comments).
• IntegerField: Used to store integer values.
• FloatField: Used to store floating point numbers.
• DateField: Used to store a date (year, month, and day).
• DateTimeField: Used to store a date and time.
• BooleanField: Used to store True/False values.
• ForeignKey: Used to represent a many-to-one relationship.
• ManyToManyField: Used to represent a many-to-many relationship.
• EmailField: Used to store an email address.

There are many other built-in field types in Django, and you can also create custom field types if
necessary.

84. What is the purpose of the “null” attribute in Django ORM?

A. To specify whether a field is required or optional
B. To specify the maximum length of a field
C. To specify the default value of a field
D. To specify whether a field can contain null values

Answer: D

The “null” attribute is used in Django ORM to specify whether a database field can be null or not. If
“null=True” is specified in a field definition, it means that the field can have a NULL value in the
database. If “null=False” or it is not specified, it means that the field must have a non-NULL value in
the database.

By default, the “null” attribute is set to False, which means that the field cannot be null. If you set
“null=True” for a field, you must also set “blank=True” if you want to allow forms to be submitted
without a value for that field.

85. What is the architectural pattern followed by Django?

A. Model-View-Controller (MVC)
B. Model-View-Template (MVT)
C. Model-View-Presenter (MVP)
D. Model-View-ViewModel (MVVM)

Answer: B

While Django is similar to MVC in some ways, it’s more accurate to describe it as following the MVT
pattern. In Django’s implementation of MVT:

• Model: Database schema and the Python code that interacts with it through the Django ORM.
• View: Python functions or classes that handle requests and responses
• Template: HTML files that define the structure and layout of the pages

86. Which of the following commands is used to load data from a fixture file in the Django shell?

A) loaddata
B) dumpdata
C) runserver
D) migrate

Answer: A

87. What is the purpose of the django.db.transaction.atomic() decorator in the Django shell?

A. To commit all changes made to the database
B. To rollback all changes made to the database
C. To prevent any changes from being made to the database
D. To ensure that changes made to the database are atomic and don’t leave the database in an inconsistent state

Answer: D

88. Which of the following is not a valid way to access the Django ORM in the Django shell?

A. Importing the model class and creating instances of it
B. Using the django.db module to query the database directly
C. Using the django.core.management.call_command() method to run management commands
D. Using the django.db.connections module to get a database connection and execute raw SQL queries

Answer: B

89. Which of the following is not a valid way to exit the Django shell?

A. Typing exit()
B. Typing quit()
C. Pressing Ctrl + C
D. Pressing Ctrl + Z

Answer: D

90. Which of the following is not a valid argument to pass to the python manage.py shell
command?

A. –no-startup
B. –plain
C. –no-color
D. –verbosity

Answer: D