Django Interview Questions

By | May 25, 2020
Django Interview Questions

Django is the most popular, Open source, and powerful Python web framework which is used to serve full-stack web development. With the increasing demand for Python, Django has also built a very massive community support for itself. If you google for web-development jobs, there you will find most of the posted jobs require Django skills from the developer. If you are preparing for an upcoming web-developer or Django interview, we would recommend you go through these Best Django interview questions.

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Django Interview Questions

Question: What is Django?

Answer: Django is a full-stack Python Web framework that is used to create dynamic web applications.

Question: From where it gets this name?

Answer: Django is named after Django Reinhardt, who was a gypsy jazz guitarist in the early 30s.

Question: On which architecture designed pattern Django works?

Answer: Django works on MVT (Model View Templates) Architecture.

Question: Give some Advantages of Using Django.

Answer:

  • It has a built-in web admin interface which can be used to handle models easily.
  • It has many pre-packaged API for common user tasks.
  • it has easy Database management.
  • It is a Python Frameworks, so it has many libraries in inheritance.
  • It can develop applications very fast, and the build quality of the applications made on Django is just amazing.

Question: Give some Features of Django.

Answer:

  • It has well-organized and complete web documentation.
  • It is SEO friendly.
  • Form handling
  • Testing Framework
  • As a Python framework, it has a large community.
  • It can handle a large amount of that which shows its high scalability.
  • It is a Full-stack web framework.
  • Admin Authentication Feature which gives its app extra security
  • Object-Relational-Mapping helps to create data using native Object-Oriented programming language.
  • It provides an inbuilt admin interface

Question: Give some disadvantages of Django.

Answer:

  • We have to specify the URL routing in Django for every view, the URL specifying syntax is complicated but it is common, for a beginner it could be confusing at first.
  • Speed is a major disadvantage of python so for Django with the increase in data it slows down work.
  • It is monolithic which means all the programming should be fall under MVT architecture the developer does not have any control over Django flow.
  • It is not an ideal framework for minor Projects

Question: Why we use include() function in project urls.py file?

Answer: We use include a function to attach the app URLs file with the project URLs file, this is a way by which we can easily do play and plug with different URLs of the different app with the project’s main URLs.

Question: Name all the inheritance possible in Django.

Answer:

  • Abstract base classes
  • Multi-table Inheritance
  • Proxy models

Question: What is the context in Django?

Answer: Context is an optional render() function attribute which is a dictionary by nature and its key is used as a template tagging in templates file.

Question: If you have worked with Flask then give some difference between Flask and Django.

Answer:

Parameters Django Flask
Projects Used for big projects Efficient with small projects
Admin It comes with a robust admin panel. Here we need to design one
Learning Curve It has a high learning curve because it contains many features. It is very easy to learn because it does not offer too much.
Debugging It supports visual debugging There is no support for visual debugging.
Framework type Full Stack framework. Micro Framework.

 

Question: How to install Django in your system?

Answer: Django is a python package so we can use the pip command to install Django.

C:\Users> pip install Django

Question: How to create a Django project?

Answer: To create a Django Project we need to open the command prompt and write this command.

django-admin startproject project_name

this will create a directory with the project_name having a subdirectory and a manage.py file

Question: By default which database does Django follow?

Answer: By default, Django has SQLite Database, but if we want we can change it with MySQL or any other Relational Databases from the setting.py file.

Question: Where we register our Models.

Answer: We need to register our models at admin.py file.

Question: What does createsuperuser subcommand do?

Answer: The createsuperuser command creates a super user, who can access the admin interface of the app

Question: Name the Caching Strategies in Django.

Answer:

  • File System caching
  • In-memory caching
  • Using Memcached
  • Database caching

Question: What is the use of manage.py in Django?

Answer: The manage.py creates automatically when we create the Django project with the Django-admin start project.

It has the following usages:

  • It put our projects packages on sys.path
  • It set a Django environment
  • It has a collection of subcommands which are used to run all Django modules.

Question: What parameters do we use in signals?

Answer:

  • Receiver
  • Sender

Question: Name the usages of middlewares in Django.

Answer:

  • Session management
  • User authentication
  • Cross-site request
  • Forgery protection
  • Content gzipping

Question: Give some drawbacks of Object Relational Mapping in Django?

Answer: Its implementation is quite complex and with a huge amount of data it also affects the speed of Django.

Question: Why do we use migration subcommand?

Answer: We use migration command to tell the Django that we have made some changes in the Model database and it needs to update those.

Question: Why do we use makemigration subcommand?

Answer: By running the makemigration command we tell Django that we have made some changes in our models and we would like to changes to be stored as a migration.

Question: What does the session framework do?

Answer: The session framework lets us store and retrieve arbitrary data on a pre-site-visitor basis. It stores data on the server-side and abstracts the sending and receiving of cookies

Questions: Name all the manage.py subcommand

Answer:  auth

  • changepassword
  • createsuperuser
  • contenttypes
  • remove_stale_contenttypes

django

  • check
  • compilemessages
  • createcachetable
  • dbshell
  • diffsettings
  • dumpdata
  • flush
  • inspectdb
  • loaddata
  • makemessages
  • makemigrations
  • migrate
  • sendtestemail
  • shell
  • showmigrations
  • sqlflush
  • sqlmigrate
  • sqlsequencereset
  • squashmigrations
  • startapp
  • startproject
  • test
  • testserver

sessions

  • clearsessions

staticfiles

  • collectstatic
  • findstatic
  • runserver

Question: Name some common Django Exceptions.

Answer:

  • AppRegistryNotRead
  • ObjectDoesNotExist
  • EmptyResultSet
  • FieldDoesNotExist
  • MultiObjectReturned
  • SuspiciousOperation
  • PermisssionDenied
  • ViewDoesNotExist
  • MiddlewareNotUsed
  • FieldError
  • ValidationError

Question: How can we register a model in Django?

Answer: We register our models at admin.py file, to register the model we use admin.site.register(model_name) command.

Question: What do you know about ‘django-admin’?

Answer: It is a Django Command-Line utility which can be used by the administrator for various task. From creating a new project to make migrations django-admin can perform all the major task that can be performed by manage.py.

Here is the list of major django-admin commands.

Commands Description
django-admin startproject project_name Create a Django based project.
django-admin help It lists all the information about the django-admin command line
django-admin help -command List out all the django-admin command.
django-admin version Show the current version of Django
django-admin makemigrations Make new migrations if there are changes in the project or app model
django-admin runserver Run the development server.
django-admin shell Open an interactive shell
django-admin startapp Create a new app directory.

Question: What are the models in Django?

Answer: Django models can be treated as a source of information about the data. Each model represents a database table, and its attributes represent database fields. In Django, models play a vital role because they provide an easy and optimize approve to create databases.

Django models also provide APIs to communicate, structure and manipulate the data.

Question: What are views in Django?

Answer: The view contains the main logics and functions about what to accept and what to show the user. It deals with the HTTP request and sends back the appropriate response. In response, the view could send anything such as HTML content, redirect notification, a message, an error, XML document, image etc. As Django work on the MVT architecture which allows the view to communicate with the app model or database.

Question: What are templates in Django?

Answer: Templates are the static part of the Django web applications, a template could be a collection of various text documents which include HTML, CSS, and JavaScript.

The template renders the information which is sent from the view section of the application.

Question: What is the difference between a Django project and Django app?

Answer: A Django project could have one or more than one application. A project is a collection of apps, whereas an app is a simple web-application which is supposed to perform some special functions in order to interact with the user.

Question: What are static files in Django?

Answer: These are the additional files which are used to make the web-application more interactive. Basically a static file containing different additional files such as CSS, images, and javascript. And Django has an inbuilt static engine to manage all these static files.

Question: What are Django mixins?

Answer: mixins are the classes predefined in Django, which are used to provide discrete functionalities. The sole purpose of mixins to make the code reusable and increase the Django DRY property.

Question: What do you know about Django sessions?

Answer: Django provides inbuilt support for sessions, which can be used to collect and show arbitrary data based on user visit. The main tasks of these sessions to store data on the server-side which can be sent and receive between the server and the user through cookies.

Question: How Django deals with cache?

Answer: In general cache provide an alternative approach to reduce the expense of creating the same dynamic page again and again on each request by the same user. Django also provides an inbuilt cache system which allows the user to save the dynamic page, so with repetitive requests, the engine does not need to recalculate the same page.

Django can deal with various types of cache which include downstream and browser-based cache, but the developer does not get the full control over the cache.

Question: What is the use of “migrate” command?

Answer: If we make changes in the Django models then we need migrate command to propagate those changes. With the help of migrate command, we can apply and un-apply the migrations. A migration in Django can be treated as version control for its models.

If a project contains more than one application then we can migrate the specific model by mentioning the application name. If making migration we do not mention the app name then migration will perform on every model of the project.

Question: What are the commands to get and filter data from the database?

Answer: In Django, we have ORM (Object Relation Mapping), which can be used to access data from the database using simple Python commands.

To get all the data from a database we can use the .object.all() command:

database_object.objects.all()

To get specific data we can use the filter and get method.

database_object.objects.filter(pk=12)
#or 
database_object.object.get(name="Sahil")

Question: How Django proceed request?

Answer: 

  • First, Django determines if the URL is valid or not.
  • If the URL is valid then the corresponding view module is loaded according to the URL pattern.
  • After that, the view module executed by the interpreter, and appropriate response send to the user.

Question: Create a view which displays heading 1 “TechGeekBuzz”, without using template or HTML document.

Answer:

from django.http import HttpResponse
def hello_world(request):
    data = "<h1>TechGeekBuzz</h1>"
    return HttpResponse(html)

Questions: List some Django exceptions.

Answer:

Exception Description
AppRegistryNotReady This exception occurs when we try to access the model without register it.
ObjectDoesNotExist It raises when you try to access an invalid Class
EmptyResultSet This exception arises when query does not return any result.
FieldDoesNotExit This exception rises when you mention invalid field value in the metadata fields list.
MultipleObjectReturned This exception occurs if the function is supposed to accept one object and multiple objects are returned.

Question: How much is stable Django?

Answer: Django is pretty stable, even various popular applications such as Instagram and Pinterest completely built on Django. Django also provides a regular annual update to stand in the market of web-frameworks. With each new update Django take some major step to stand at the top. With time Django has gained too much popularity and now many web-projects use it to build a robust back-end application.

Question: Do we need a specific python version to work with Django?

Answer: No, we can use any Django version with any Python version, but there is some matches compatibility which highly recommended when we choose to work on specific Django version.

Python Versions Django Versions
1.11 2.7, 3.4, 3.5, 3.6 and 3.7
2.0 3.4, 3.5, 3.6, and 3.7
2.1, 2.2 3.5, 3.6, and 3.7
3.0 3.6, 3.7 and 3.8

Question: Can we use NoSQL instead of SQL with Django?

Answer: Django originally supports the SQL database system such as PostgreSQL, MySQL, SQLite, etc, but with the help of some third-party tools we can integrate NoSQL with Django.

Question: How can we use the file-based session in Django?

Answer: To use the file-based session in the setting we need to set the SESSION_ENGINE to "django.contrib.sessions.backends.file".

Question: Is Django a Content Management System (CMS)?

Answer: No, it is not a CMS, it’s just a python web-framework. However, we can use it to built CSM applications.

Question: What is csrf_token?

Answer: CSRF stands for Cross-Site Request Forgeries, and it is a protection used with Django forms to fight against malicious attacks.

Question: Can a Django model have multiple primary keys?

Answer: No, In Django models, we can only have a single column for primary key.

Question: What commands we can use to see the raw queries running by the Django?

Answer: In the Command shell run this commands.

from django.db import connection
connection.queries

Question: What is Serialization?

Answer: In Dango using the concept of serialization we can convert the model’s data into other transferable data formats such as XML, JSON, etc.

Question: What is DjangoRestFramework?

Answer: It is a Django toolkit which can be used to build robust REST API’s. It comes with authentication policies which include packages like OAuth1a and OAuth2.

It can be installed using the python-pip command.

pip install djangorestframework

Conclusion: 

With this, we have reached at the end of our Django interview questions and answers, we hope you read these questions before you appear in the interview. If you have appeared in any Django interview in last few months or years, please comment down the technical questions you tackled during the interview.

If you like this article or have any suggestions please let us know by commenting down below.

 

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Author: Paridhi Joshi

Paridhi Joshi is an expert web content manager with significant experience in content creation. Professionally she is dedicated to staying up to date with the latest trends and technologies in content writing and committed to bringing state-of-the-art web approaches to the workplace. She is an efficient multi-tasker who can complete multiple projects under strict deadlines.

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