Django Interview Questions and Answers

Ques 1. Can you customize Django’s admin interface? If yes, then how?

Yes, you can customize Django’s admin interface. Django’s admin is another entirely customizable application. It enables you to download another third-party application for a different view. You can create your own admin application to have complete control over it. Also, for customizing the Django admin site, you can change the settings of the admin site object.

Also, you can make the desired changes to your models and then apply them in the Django admin for adding specific applications, such as the search bar. You can customize even a smaller detail of your Django admin interface. Still, it is advisable to create a new admin rather than making so many changes at a lower level.

Ques 2. Why is Django considered a loosely coupled framework?

Django is considered a loosely coupled framework, as it is based on the MVT architecture, a variant of the MVC architecture. The MVT architecture is useful because it entirely separates the server code from the client’s machine.

Models and views are available on a client machine. However, the client only receives the template — the HTML and CSS code — along with the data from the models.

Since these components are different, the front-end and back-end developers can work together on the same project. Making changes to a project by both the teams will not impact each other, thus making Django a loosely coupled framework.

Ques 3. What is the settings.py file, and what does it contain?

Whenever you start the Django server, initially, it looks for the settings.py file, containing the main settings regarding a web application. Also, it contains everything related to your web application, such as databases, a backend engine, templating engines, static file addresses, servers, security keys, middlewares, URL configs, and other essential data.

So, when you start the Django server, it will first execute the settings.py file and, later, load the required engines and databases.

Ques 4. Why are regular expressions used for defining the URLs?

Django has a powerful way of storing the URLs that are regular expressions. You can easily use the regular expression format for string searching algorithms, making the search process faster.

However, after the release of Django 2.2 and later versions there is no need to use the regular expression for defining the URL. Instead, you can use normal strings. The regular expression is used whenever you want to pass some data from the user via the URL. But whatever you use, the Django server needs to match them.

Ques 5. Explain ORM in Django.

ORM stands for Object-relational mapper, a special feature tool of Django. This tool helps developers to interact with the database in a more Python-esque way. It acts as the abstraction between the models and the database, where the main data is stored.

Using ORM, you can retrieve, save, and delete the data from a database without the need to write any SQL code for it. This tool will help eliminate many loopholes since it lets you maintain control over your code, and is developed in Python.

It does not matter whether the Database is a SQLite, MySQL, Postgre or Oracle the ORM makes sure that the developer writes the same code for all databases.

Django uses the ORM known as Django ORM, it uses classes inherited from models.Modle, to create tables under any database.

The only thing we need to tweak is the database settings in the setting.py file.

DATABASES = {    'default': {        'ENGINE': 'django.db.backends.postgresql',         'NAME': 'DB_NAME',        'USER': 'DB_USER',        'PASSWORD': 'DB_PASSWORD',        'HOST': 'localhost',          'PORT': '5432',    }}

Ques 6. How does templating work in Django?

Templates are the reason behind Django’s ability to create dynamic web pages. These templates are HTML code returned as an HTTP response. Furthermore, Django has a templating engine capable of handling templating. You can use some of the template syntaxes while declaring the variables, control logic, and comments.

Once you provide all the template syntax within the HTML structure, the web page is requested and called by the view function. Later, the Django template engine will get the HTML structure with variables and the data to replace these variables. The templating engine will replace these while executing the control logic and generating filters. It will then render the required HTML and send it to the browser.

Ques 7. What are view functions? Can you directly import a function within the URL?

A view is a middle layer between a model and a template, and it will take the data from the model and pass it to a template. Every application in Django has the view.py file that stores view functions, and these functions take the argument and return the browser-renderable format.

You can easily import view functions in the URL file. To do so, you need to import the view function in the urls.py file and add the desired path required by the browser to call that function.

Ques 8. What does the urls-config file contain?

This config file stores all the URL lists and mapping to their respective view functions. These URLs can be mapped to view functions, class-based views, and url-config of another application.

The default URL list name is urlpatterns, and it contains all the path() or re_path() URL patterns. The project URL comes with the root urls.py file, and with every application, we can also make an isolated urls.py file for that application.

Example:

from django.contrib import adminfrom django.urls import path, includeurlpatterns = [    path('admin/', admin.site.urls),    path(blog/', include('blog.urls')),]

Ques 9. What is Jinja templating?

Django comes with the support for many popular templating engines, and by default, it comes with one very powerful templating engine, called Jinja Templating. The latest version is Jinja 2.

Below are some features of the Jinja templating, making it a better option than another templating engine available.

• Sandbox Execution: It is a protected framework useful for automating the testing process
• HTML Escaping: Jinja 2 comes with an automatic HTML Escaping, as <, >, & characters that have special values in templates. If you use it as regular text, these symbols can lead to XSS Attacks, handled by Jinja automatically.
• It shows template inheritance and generates HTML templates much faster than the default engine
• It is easier to debug with Jina compared to the default engine

Ques 10. What is the purpose of middleware in Django?

In Django, middleware is the component that works on request and transfers it to the view, and before it passes it to the template engine, it starts operating on a response.

Ques 11. What is mixin in Django?

Mixin is a type of multiple inheritances that combines the behaviors and attributes of more than one parent class. It provides an excellent way of reusing the code from multiple classes.

For example, generic class-based views have a mixin called TemplateResponseMixin. This mixin is used for defining the render_to_response() method. When you combine it with a class present in the View, it results in a TemplateView class.

The only drawback of mixin is that it becomes difficult to analyze what a child class is doing and which methods to override if its code scatters between multiple classes.

Ques 12. What are caching strategies in Django?

Caching implies storing the output of calculations to avoid performing the same calculations repetitively. Django comes with a robust cache system helping to create dynamic pages. Therefore, it eliminates the need to evaluate pages repeatedly for every request. The following table highlights some of the significant caching strategies:

Ques 13. How is the “migrate” command used in Django?

In Django, migrations are used for propagating the changes made to models. You can use the migrate command to apply and remove the migration changes made to models.

This command helps synchronize the current set of models and migrations with the database state. You can also use this command with or without passing the parameters. If you do not specify any parameters, all apps will have all their migrations running.

Ques 14. What is the difference between select_related and prefetch_related?

queryset = Blog.objects.select_related('Author').all()

queryset = Blog.objects.prefetch_related('Categories').all()

Ques 15. What are the different tasks that can be performed using Django-admin?

Django-admin is the command-line utility of Django used for carrying out administrative tasks. The below table highlights various tasks performed using Django-admin:

Ques 16. What are the different types of views available in Django?

The following are the two different types of views available in Django:

Ques 17. What is a model in Django?

A Model is specified as a Python class derived from the Model class. This model class is imported from the django.db.models library. The main concept of Django Models is to create objects for storing data from a user in a user-defined format.

The model class is a pre-defined class with lots of benefits. You can define the field with specific attributes as you can do in SQL, but the same can also be achieved in Python.

This class is parsed by Django ORM or backend engine, and there is no need to do anything related to a database, such as creating tables and defining fields afterward mapping the fields with the attribute of the class.