Python & Django Interview Questions

Question 1

What is Django and what is its architecture pattern?

Accepted Answer

Django is a Python web framework following the MVT (Model-View-Template) pattern for rapid, secure web development. Django's MVT: Model (database layer, ORM), View (business logic, handles requests), Template (presentation layer, HTML). Unlike MVC, Django's View is the controller. Key features: built-in admin, ORM, authentication, URL routing, template engine, middleware, and security features (CSRF, XSS, SQL injection protection). 'Batteries included' philosophy means most web features are built-in.

Question 2

What is the Django ORM?

Accepted Answer

Django's ORM maps Python classes to database tables, allowing you to query databases using Python code instead of SQL. Models define schema: class User(models.Model). Field types: CharField, IntegerField, ForeignKey, ManyToManyField. QuerySet API: User.objects.filter(age__gte=18).order_by('name'). Supports: chaining, aggregation, annotation, F expressions (database-level operations), Q objects (complex queries). Migrations auto-generate from model changes. Supports PostgreSQL, MySQL, SQLite, Oracle. Raw SQL available when needed: User.objects.raw('SELECT ...').

Question 3

What are Django migrations?

Accepted Answer

Migrations are auto-generated Python files that track and apply database schema changes based on model definitions. Workflow: (1) Modify models.py. (2) python manage.py makemigrations — generates migration file. (3) python manage.py migrate — applies to database. Migrations are version-controlled. Support: creating/dropping tables, adding/removing columns, data migrations (RunPython). Squash migrations to consolidate. Commands: showmigrations (list), sqlmigrate (show SQL), migrate --fake (mark without running). Always test migrations in staging before production.

Question 4

What is the difference between a function-based view and a class-based view?

Accepted Answer

FBVs are simple functions handling requests; CBVs use classes with built-in methods for common CRUD patterns. FBVs: def my_view(request): return HttpResponse('Hello'). Simple, explicit, good for unique logic. CBVs: class MyView(View): def get(self, request): ... — provide mixins (LoginRequiredMixin, CreateView, ListView) for DRY code. Generic CBVs handle CRUD automatically. FBVs are easier to understand; CBVs reduce boilerplate for standard operations. Choose FBVs for custom logic, CBVs for standard CRUD. DRF uses CBVs extensively (APIView, ViewSet).

Question 5

How does URL routing work in Django?

Accepted Answer

Django uses urlpatterns in urls.py to map URL patterns to view functions/classes using path() or re_path(). urls.py: urlpatterns = [path('articles//', views.article_detail)]. Path converters: , , , . Include app URLs: path('api/', include('myapp.urls')). Named URLs: path('home/', views.home, name='home'). Reverse URL: reverse('home'). Namespace: app_name = 'blog'. URL resolution is top-down — first match wins. Django 2.0+ uses path() (simplified), re_path() for regex patterns.

Question 6

How does Django handle security?

Accepted Answer

Django provides built-in protection against CSRF, XSS, SQL injection, clickjacking, and includes secure authentication. Security features: (1) CSRF: middleware adds token to forms, validates on POST. (2) XSS: template auto-escaping ({{ variable }} is escaped). (3) SQL Injection: ORM parameterizes queries. (4) Clickjacking: X-Frame-Options middleware. (5) Password storage: PBKDF2 hashing with salt. (6) HTTPS: SECURE_SSL_REDIRECT, SECURE_HSTS_SECONDS. (7) Content-type sniffing protection. (8) Session security: SESSION_COOKIE_HTTPONLY, SESSION_COOKIE_SECURE. Always run python manage.py check --deploy before deploying.

Question 7

What is Django REST Framework (DRF)?

Accepted Answer

DRF is a toolkit for building Web APIs in Django with serializers, viewsets, authentication, and browsable API. Key components: (1) Serializers: convert models to JSON and validate input (ModelSerializer). (2) ViewSets: combine list/create/retrieve/update/delete in one class. (3) Routers: auto-generate URL patterns. (4) Authentication: Token, Session, JWT (via simplejwt). (5) Permissions: IsAuthenticated, IsAdminUser, custom. (6) Pagination: PageNumber, LimitOffset, Cursor. (7) Filtering: django-filter integration. (8) Throttling: rate limiting. (9) Browsable API for easy testing. Most popular choice for Django APIs.

Question 8

Explain Django middleware.

Accepted Answer

Middleware is a framework of hooks that process requests/responses globally, running before views and after responses. Middleware chain: Request → SecurityMiddleware → SessionMiddleware → AuthenticationMiddleware → View → Response (reverse order). Custom middleware: class MyMiddleware: def __init__(self, get_response): ... def __call__(self, request): ... response = self.get_response(request) ... return response. Built-in: CSRF, session, auth, GZip, locale. Use for: logging, request timing, modifying headers, IP blocking, custom auth. Order in MIDDLEWARE setting matters — security first.

Question 9

How do you optimize Django ORM queries?

Accepted Answer

Use select_related, prefetch_related, values/only, indexing, and avoid N+1 queries. Techniques: (1) select_related(): JOIN for FK/OneToOne (single query). (2) prefetch_related(): separate query for M2M/reverse FK. (3) .only()/.defer(): load specific fields. (4) .values()/.values_list(): return dicts/tuples instead of objects. (5) Database indexes on filtered/ordered fields. (6) django-debug-toolbar to see queries. (7) Bulk operations: bulk_create, bulk_update. (8) Avoid queryset evaluation in loops. (9) Use .count()/.exists() instead of len()/bool(). (10) Raw SQL for complex queries.

Question 10

What is Django's caching framework?

Accepted Answer

Django supports per-site, per-view, and template fragment caching with backends like Redis, Memcached, and database. Backends: Redis (django-redis), Memcached, database, file-based, local memory. Levels: (1) Per-site: CacheMiddleware caches entire site. (2) Per-view: @cache_page(60*15) decorator. (3) Template fragment: {% cache 500 sidebar %}. (4) Low-level: cache.set('key', value, timeout). Cache key versioning, cache invalidation strategies. Use Vary header for user-specific caching. Django's cache framework is configurable — switch backends without code changes.

Complete Python Course 2026 — Beginner to Advanced

Who This Course Is For

Prerequisites

What You'll Learn

Career Opportunities

Course Completion Certificate

Course Modules Overview

Python Fundamentals & Setup

Control Flow & Loops

Functions & Scope

Data Structures — Lists, Tuples & Sets

Dictionaries & Data Handling

Object-Oriented Programming (OOP)

File Handling & Exception Handling

Modules, Packages & Virtual Environments

Advanced Python Concepts

Working with APIs & Automation

Debugging, Testing & Optimization

Python Real-World & Career

Course Curriculum

Python Fundamentals & Setup

Control Flow & Loops

Functions & Scope

Data Structures — Lists, Tuples & Sets

Dictionaries & Data Handling

Object-Oriented Programming (OOP)

File Handling & Exception Handling

Modules, Packages & Virtual Environments

Advanced Python Concepts

Working with APIs & Automation

Debugging, Testing & Optimization

Python Real-World & Career

Your Learning Roadmap

Tools & Technologies

Python 3.12+

VS Code

pip

venv

pytest

Jupyter

Ready to Start Learning?

Related Free Courses

Node.js Course

SQL Course

Machine Learning Course

Cloud Computing Course

Watch Our Free Python Video Tutorials