FastAPI vs Flask vs Django comparison - Quick Revision & Key Differences

Recall & Review

beginner

What is FastAPI mainly known for?

FastAPI is known for its speed and automatic generation of API documentation using Python type hints.

beginner

How does Flask differ from Django in terms of project structure?

Flask is a micro-framework that gives you freedom to structure your project as you like, while Django provides a full-featured, structured framework with built-in components.

beginner

Which framework includes an admin panel out of the box?

Django includes a built-in admin panel for managing data, which FastAPI and Flask do not provide by default.

intermediate

Why might a developer choose FastAPI over Flask or Django?

A developer might choose FastAPI for its modern async support, automatic docs, and better performance for APIs.

beginner

What is a key advantage of Flask for beginners?

Flask's simplicity and minimal setup make it easy for beginners to start building web apps quickly.

Which framework automatically generates API documentation from your code?

A Flask

B Django

C FastAPI

D None of the above

FastAPI uses Python type hints to generate interactive API docs automatically.

Which framework is considered a micro-framework?

A Django

B Flask

C FastAPI

D All of them

Flask is a micro-framework, meaning it provides the basics and lets you add features as needed.

Which framework includes a built-in admin interface?

A None

B Flask

C FastAPI

D Django

Django comes with a built-in admin panel to manage database content easily.

Which framework is best known for supporting asynchronous programming easily?

A FastAPI

B Django

C Flask

D All support it equally

FastAPI is designed with async support for better performance in handling many requests.

If you want a simple, flexible framework to start a small web app quickly, which should you pick?

A Flask

B FastAPI

C None

D Django

Flask is simple and flexible, making it great for beginners and small projects.

Explain the main differences between FastAPI, Flask, and Django in terms of features and typical use cases.

Think about speed, structure, and built-in tools.

Describe why a developer might choose Django over FastAPI or Flask for a new project.

Consider project size and built-in features.

Practice

1. Which framework is best known for being modern, fast, and supporting automatic type checking for APIs?

easy

A. Flask

B. Pyramid

C. Django

D. FastAPI

Solution

1. Step 1: Understand framework features

   FastAPI is designed to be modern and fast, with built-in support for Python type hints to validate and document APIs automatically.

2. Step 2: Compare with other frameworks

   Flask is minimal and easy to start but lacks built-in type checking. Django is full-featured but more heavyweight and not focused on type checking.

3. Final Answer:

   FastAPI -> Option D

4. Quick Check:

   Modern + fast + type checking = FastAPI [OK]

Hint: Modern + fast + type hints = FastAPI [OK]

Common Mistakes:

• Confusing Flask's simplicity with FastAPI's speed
• Thinking Django has built-in type checking
• Choosing Pyramid which is less common

2. Which of the following is the correct way to create a simple route in Flask?

easy

A. app.route('/')(def home(): return 'Hello')

B. @app.route('/')
def home():
return 'Hello'

C. app.get('/')
def home():
return 'Hello'

D. @app.get('/')
def home():
return 'Hello'

Solution

1. Step 1: Recall Flask route syntax

   In Flask, routes are created using the @app.route decorator above a function.

2. Step 2: Identify correct decorator and syntax

   @app.route('/') def home(): return 'Hello' uses @app.route('/') with proper Python function definition and indentation, which is correct Flask syntax.

3. Final Answer:

   @app.route('/') def home(): return 'Hello' -> Option B

4. Quick Check:

   Flask route decorator = @app.route [OK]

Hint: Flask uses @app.route decorator, not app.route() call [OK]

Common Mistakes:

• Missing @ symbol before decorator
• Using app.get instead of app.route in Flask
• Incorrect indentation or function syntax

3. Given this FastAPI code snippet, what will be the output when accessing /items/5?

from fastapi import FastAPI
app = FastAPI()

@app.get('/items/{item_id}')
async def read_item(item_id: int):
    return {'item_id': item_id * 2}

medium

A. {'item_id': 10}

B. {'item_id': '5'}

C. {'item_id': 5}

D. Error: item_id must be a string

Solution

1. Step 1: Understand path parameter and type

   The route expects an integer item_id. When accessing /items/5, item_id is 5 as int.

2. Step 2: Calculate returned value

   The function returns a dictionary with 'item_id' key and value item_id * 2, so 5 * 2 = 10.

3. Final Answer:

   {'item_id': 10} -> Option A

4. Quick Check:

   5 * 2 = 10 output [OK]

Hint: Multiply path param by 2 as int to get output [OK]

Common Mistakes:

• Assuming item_id is string, not int
• Returning original item_id instead of multiplied
• Expecting error due to type mismatch

4. Identify the error in this Django view code snippet:

from django.http import HttpResponse

def home(request):
return HttpResponse('Hello')

medium

A. Indentation error in function body

B. HttpResponse should be replaced with JsonResponse

C. Missing import for HttpRequest

D. Function name must be capitalized

Solution

1. Step 1: Check Python syntax rules

   Python requires the function body to be indented under the def line.

2. Step 2: Identify indentation problem

   The return statement is not indented, causing a syntax error.

3. Final Answer:

   Indentation error in function body -> Option A

4. Quick Check:

   Python function body must be indented [OK]

Hint: Check indentation under def for Python functions [OK]

Common Mistakes:

• Ignoring indentation errors
• Thinking import is missing
• Assuming JsonResponse is mandatory

5. You want to build a large, complex web app with built-in admin, user authentication, and database ORM. Which framework is the best choice and why?

hard

A. FastAPI, because it is the fastest and has built-in admin

B. Flask, because it is minimal and easy to add features manually

C. Django, because it is full-featured with admin, auth, and ORM included

D. FastAPI, because it supports async and type checking

Solution

1. Step 1: Identify requirements for large complex app

   Needs built-in admin panel, user authentication, and ORM for database management.

2. Step 2: Match framework features to requirements

   Django provides all these features out of the box, making it ideal for large apps. FastAPI and Flask require extra setup for these.

3. Final Answer:

   Django, because it is full-featured with admin, auth, and ORM included -> Option C

4. Quick Check:

   Full features for big apps = Django [OK]

Hint: Full features + admin + auth = Django [OK]

Common Mistakes:

• Choosing FastAPI for admin features it lacks
• Thinking Flask has built-in admin
• Ignoring Django's batteries-included approach