The Django web framework provides a high-level, Python-based framework for creating database-driven web applications and websites. It is based on the MVT (Model-View-Template) architectural pattern. The Django Software Foundation (DSF) maintains Django under the 3-clause BSD license. It simplifies the process of building complex database-driven websites for Python developers. Components can be plugged and reused, rapid development is possible, and there is a low coupling factor in the design, as well as the principle of Don't Repeat Yourself (DRY).
Due to its popularity and widespread usage, Python is the preferred programming language of many developers. Learning Django would open up dozens of career opportunities since it is one of the most widely recognized Python web frameworks.
The article highlights frequently asked Django interview questions and answers, so you can ace your interview. Concepts ranging from the very basics to more advanced ones are covered. Keep this article handy if you already have some experience with Django, so you can brush up whenever you need to.
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Django Interview Questions
1. What is Django?
Django is a python web framework that enables web developers to quickly generate secure and maintainable websites. It is free to use and open source. With it, you don't need to reinvent the wheel and can focus on writing apps without having to deal with much of the hassle of web development. Developers will be able to spend more time developing new components instead of already developed ones thanks to this framework.
Here's an example of a Django Hello World!! Program.
Step 1: Create a project
django-admin startproject example_projectStep 2: Navigate to the example_project directory
cd example_projectStep 3: Write the hello world function in views.py
from django.shortcuts import HttpResponse
view def hello_world(request):
return HttpResponse("Hello World")Step 4: Use urls.py to route the hello world URL
from django.contrib import admin
from django.urls import path
from .views import hello_world
urlpatterns = [
path('admin/', admin.site.urls),
path('', hello_world, name="hello-world")
]Step 5: Run Python's manage.py runserver command to start the server
python manage.py runserver
In Django, here's how you can write a hello world program. Django is a monolithic programming language, so it's best suited for large projects. However, even a small application like Hello World has several steps to follow.
2. What are the advantages of using Django?
The Django stack is loosely coupled and tightly cohesive
A Django application uses a very small amount of code
Ensures quick website development
It adheres to the DRY (Don't Repeat Yourself) principle, which means one concept or piece of data should live only in one place
Achieves consistency at both low and high levels
Rather than implicitly assuming behavior, it is explicitly specified
The execution of SQL statements is optimized internally so that they are not executed too often
When necessary, it is easy to switch to raw SQL
Use of URLs with flexibility
3. In what ways is Django disadvantageous
Developers still find it difficult to adapt to the new environment despite its many advantages. The following are some of Django's disadvantages:
There are no conventions for web development in Django that can be followed by developers.
It has a large structure and heavy functionalities, so it's not suitable for smaller projects with few requirements
Django's monolithic nature requires developers to follow predefined patterns.
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4. Explain the Django project directory structure??
manage.py - A command-line tool for managing Django projects
init.py - This file tells Python to recognize the current directory as a Python package
settings.py - Configures the project's database connection and other elements.
urls.py - This file contains all the project's URLs
wsgi.py - Provides a way for the web servers to access your application to serve your project.
5. What are models in Django?
Models in Django correspond to database tables or collections. The attributes of the Django model class correspond to database fields. Models are defined in app/models.py
Example:
from django.db import models
class SampleModel(models.Model):
field1 = models.CharField(max_length = 80)
field2 = models.IntegerField()
class Meta:
db_table = “sample_model”The Model class is inherited by all models in Django.db.models.Model. There are two fields in our example table, one a char and one an integer.
A metaclass allows you to specify things like permissions, plural and singular names, associated database table names, and whether or not the model is abstract.
7. What are templates in Django
The Django MVT architecture relies heavily on templates. Typically, these web pages contain HTML, CSS, and JS, embedded with dynamic variables and information. The template engine recognizes and interprets some constructs. Variables and tags are the most common.
Templates are rendered with contexts. When rendering, variables are replaced with their values, which are present in the context, and tags are processed. The rest remains the same.
In the Django template language, there are four constructs:
Variables
Tags
Filters
Comments
8. What are views in Django?
View functions are simply Python functions that take a web request and return a web response. Responses can be HTML pages, redirects, 404 errors, or XML documents, images, or other types of files.
Example:
from django.http import HttpResponse
def sample_function(request):
return HttpResponse(“Django Interview Questions”)Views can be categorized into two types:
Function-Based Views: Using this approach, we import our view as a function.
Class-based Views: The approach is object-oriented
9. Explain the use of Middlewares in Django.
It is likely that you will find this question in numerous Django Interview Questions. The middleware framework is a lightweight low-level plug-in system that enables Django to alter its input and output globally. Django's request/response processing is incorporated into this framework. Each middleware component performs a specific task. AuthenticationMiddleware, for instance, associates users with requests using sessions. There are a number of other middlewares provided by Django, including cache middleware that enables site-wide caching, common middleware that performs tasks like rewriting URLs, forbidding access to user agents, and GZIP middleware that compresses content for browsers.
10. What is django.shortcuts.render function?
When we want a view function to return an HttpResponse rather than a simple string, we call render(). Developers can pass the data dictionary with the template using the render function as a shortcut. By using a templating engine, this function combines the template with a data dictionary. At the end of this process, render() returns a HttpResponse that contains the text received from models as a HttpResponse. In this way, Django render() allows the developer to use a variety of template engines without doing much of the work himself.
Here is the basic syntax:
render(request, template_name, context=None, content_type=None, status=None, using=None)Responses are generated by the request parameter. HTML templates are named after their HTML templates, while Python data is passed through a dict called context. Besides specifying content type, status, and render, you can also specify the type of data you are passing
11. What are the applications of Django?
Django allows you to create the following types of projects:
Data-driven financial platforms with a range of features, including analysis and calculations
Internal CRM system customized to the company's needs
The B2B CRM system that helps you manage internal communications
Online shopping sites
An evaluation system for real estate properties
Document management system
Creating an emailing system to send notifications
Photo-based verification system
Management platforms for investment funds
12. Explain Django URL in brief?
URL functions can be designed however you want in Django. In order to achieve this, you must create a Python module called URLconf (URL configuration). Python code is solely responsible for mapping URL path expressions to Python functions in this module. This mapping can also reference other mappings and be as long or short as needed. You can create this mapping in any length you like by referring to other mappings. URLs can also be translated according to the language being used in Django
13. Describe the Django architecture.
This architecture is based on the Model-View-Template(MVT) pattern, which is common in many web-frameworks, such as Rails, Laravel, and Ruby on Rails.
In Django, the application is conceptually divided into three components:
Model
View
Template
Each of these components handles a different aspect of the web application.
Model: A model handles the database schema for a web application. Data from the entire application is maintained and represented in the database. Generally, the model uses SQLite as the relational database in development, but MySQL or Postgres can be used in production.
View: The view component is responsible for rendering all the logic of the application on the user's browser. Views serve as bridges between models and templates in Django. A view renders the data from a model on a template by fetching it from the model.
Template: A template is a collection of static files like HTML, CSS, JavaScript, and images that make up the application. In order to display the content on the user's browser, the template is used as the basis for presenting the data, since the web application uses static files to represent the content.
14. What is the significance of manage.py file in Django?
Whenever you create a project, manage.py is automatically generated. It provides you with various ways to interact with your Django project from the command line. This module has the same functionality as django-admin, but it also sets an environment variable called DJANGO_SETTINGS_MODULE to identify your project's settings. If you are working on a single project, it is usually better to use manage.py rather than django-admin.
15. What is the best time to use iterators in Django ORM?
Python iterators are containers containing countable elements. Every iterator implements two methods: init() and next (). Django iterators are best used when you have to process large amounts of memory-intensive results. With the iterator() method, you can retrieve the results from a QuerySet by evaluating it and returning an iterator.
16. Django is monolithic? What does this statement mean?
To some extent, it is true that Django is monolithic. As Django is an MVT-based architecture, developers must follow certain rules to ensure that the right files are executed when they need them. Implementations with Django can be customized in a significant way. The names of files, variables, and predefined lists cannot be changed through this method. The file structure of Django is logically organized. Therefore, Django's monolithic behavior makes it easier for developers to understand the project.
17. What is the process for adding View functions to urls.py?
A view function can be added to the main URLs configuration in two ways:
Method 1. Adding a function View
Import the function of the particular View and add the URL pattern to the URL pattern list.
Method 2. Adding a Class-based view
In this case, the approach is more class-based. The URL patterns must be added after importing the class from views.py. The class must be called as a view using an inbuilt method.
The previous method's function name is as follows:
class_name.as_view()Your view class will be passed as a view function. Using a function-based or class-based approach has its advantages and disadvantages. Depending on the situation, you can use them to get the best results.
18. Explain the admin interface in Django.
Django already offers an admin interface. This eliminates the need for developers to create another admin panel, saving them time. A package named django.contrib contains Django admin, which can be easily imported. Users can log in with their Google accounts, and there are other features, such as managing models and CMSs.
When the project has been migrated and a new superuser created, two default models are included in the admin interface: Groups and Users. Default admin access is available at http://127.0.0.1:8000/admin/, which is the URL to the admin panel.
19. What is mixin?
A mixin is a type of multiple inheritances that combines the behaviors and attributes of more than one parent class. Code from multiple classes can be reused with mixins. In generic class-based views, the render_to_response() method is defined by a mixin called TemplateResponseMixin. A TemplateView class will be created if this is combined with a class present in the View. The drawback of using mixins is that a child class's code may be too scattered between multiple classes, making it difficult to analyze its behavior and override its methods.
20. What is Django Field Class?
Fields are abstract classes that represent columns in database tables. A Field class is just a subclass of a RegisterLookupMixin class. With the help of get_prep_value() or from_db_value(), Python types are mapped to databases in Django using these fields. As a result, fields are fundamental components in Django APIs like models and query sets.
Conclusion
In this article, we have covered the best Django interview questions you won't find anywhere else. These are descriptive answers that will be particularly helpful to you in developing your understanding of the framework and achieving success in the interview.
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