Flask vs Django decision - Practice Questions

Challenge - 5 Problems

🧠 Conceptual

intermediate

Choosing Flask or Django for a small project

You want to build a simple web app with a few pages and minimal database use. Which framework is better suited for quick setup and flexibility?

A Flask, because it is lightweight and lets you add only what you need.

B Django, because it has many built-in features and enforces structure.

C Django, because it requires less coding for small projects.

D Flask, because it automatically generates admin interfaces.

💡 Hint

Think about which framework is minimal and flexible for small apps.

Flask is lightweight and flexible, ideal for small projects where you want to add only needed features. Django is more heavyweight with many built-in parts, better for larger projects.

❓ component_behavior

intermediate

How Django handles database migrations compared to Flask

Which statement correctly describes how Django and Flask handle database schema changes?

A Flask has built-in migration tools that automatically update the database schema.

B Django requires manual SQL scripts for every schema change.

C Django uses built-in migration tools to track and apply schema changes automatically.

D Flask automatically detects and applies schema changes without extra setup.

💡 Hint

Consider which framework includes built-in tools for database migrations.

Django includes built-in migration tools that track model changes and apply them to the database. Flask requires external libraries like Alembic for migrations.

📝 Syntax

advanced

Identifying correct Flask route syntax

Which Flask route definition will correctly respond to GET requests at URL '/hello'?

Flask

from flask import Flask
app = Flask(__name__)

@???
def hello():
    return "Hello!"

A @app.route('/hello', method='GET')

B @app.route('/hello', methods='GET')

C @app.route('/hello', get=True)

D @app.route('/hello', methods=['GET'])

💡 Hint

Check the correct keyword and value type for specifying HTTP methods in Flask routes.

The 'methods' parameter expects a list of HTTP methods. Option D uses the correct syntax with a list ['GET'].

❓ state_output

advanced

Django template rendering output

Given this Django template snippet and context, what will be the rendered output?

Flask

{% if user.is_authenticated %}
  Welcome, {{ user.username }}!
{% else %}
  Please log in.
{% endif %}

A Welcome, alice!

B Please log in.

C Welcome, {{ user.username }}!

D Error: user is not defined

💡 Hint

Assume the context has user.is_authenticated = True and user.username = 'alice'.

The template checks if the user is authenticated. Since true, it renders the welcome message with the username.

🔧 Debug

expert

Debugging Flask app context error

What error will this Flask code raise when trying to access request.args outside a request context?

Flask

from flask import Flask, request
app = Flask(__name__)

print(request.args)

A No error, prints an empty ImmutableMultiDict.

B RuntimeError: Working outside of request context.

C NameError: name 'request' is not defined.

D AttributeError: 'NoneType' object has no attribute 'args'.

💡 Hint

Think about when Flask's request object is available.

The request object is only available during an active HTTP request. Accessing it outside raises a RuntimeError.

Practice

1. Which framework is best suited for a beginner who wants to learn web development step-by-step with a simple app?

easy

A. Angular

B. Django

C. React

D. Flask

Solution

1. Step 1: Understand beginner needs

   A beginner usually needs a simple, easy-to-understand framework to learn web development basics.

2. Step 2: Match framework to needs

   Flask is lightweight and simple, perfect for learning step-by-step, unlike Django which is more complex.

3. Final Answer:

   Flask -> Option D

4. Quick Check:

   Simple beginner app = Flask [OK]

Hint: Simple and small apps? Pick Flask [OK]

Common Mistakes:

• Choosing Django for simple beginner apps
• Confusing Flask with frontend frameworks
• Thinking React or Angular are backend frameworks

2. Which of the following is the correct way to start a basic Flask app?

easy

A. from flask import Flask
app = Flask()

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

B. import django
app = django.App()

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

C. from flask import Flask
app = Flask(__name__)

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

D. from flask import Flask
app = Flask(__file__)

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

Solution

1. Step 1: Check Flask app initialization

   Flask apps require passing __name__ to Flask() for correct setup.

2. Step 2: Verify route and function syntax

   from flask import Flask app = Flask(__name__) @app.route('/') def home(): return 'Hello World!' correctly imports Flask, initializes app with __name__, and defines a route with a function returning a string.

3. Final Answer:

   Correct Flask app start with __name__ -> Option C

4. Quick Check:

   Flask(__name__) is correct app init [OK]

Hint: Flask app needs Flask(__name__) to start [OK]

Common Mistakes:

• Using Flask() without __name__
• Confusing Django import with Flask
• Passing wrong argument like __file__

3. Given this Flask app code, what will be the output when accessing the root URL /?

from flask import Flask
app = Flask(__name__)

@app.route('/')
def home():
    return 'Welcome to Flask!'

medium

A. Welcome to Flask!

B. Empty page

C. 500 Internal Server Error

D. 404 Not Found error

Solution

1. Step 1: Analyze route decorator

   The route '/' is defined and linked to the home() function.

2. Step 2: Check function return value

   The home() function returns the string 'Welcome to Flask!'. Flask sends this as the response body.

3. Final Answer:

   Welcome to Flask! -> Option A

4. Quick Check:

   Route '/' returns string output [OK]

Hint: Route '/' returns function's string output [OK]

Common Mistakes:

• Expecting error instead of string output
• Confusing route URL with function name
• Thinking Flask returns empty page by default

4. You wrote this Flask code but get an error when running it:

from flask import Flask
app = Flask(__name__)

@app.route('/hello')
def hello():
print('Hello World!')

What is the main issue causing the error?

medium

A. Indentation error inside the function

B. Missing parentheses in print statement

C. Route decorator syntax is wrong

D. Flask app not initialized properly

Solution

1. Step 1: Check function body indentation

   Python requires the function body to be indented; here, print is not indented.

2. Step 2: Confirm other syntax correctness

   Print statement has parentheses (Python 3), route decorator syntax and app initialization are correct.

3. Final Answer:

   Indentation error inside the function -> Option A

4. Quick Check:

   Python needs indented function bodies [OK]

Hint: Check indentation inside functions for errors [OK]

Common Mistakes:

• Assuming print needs fixing in Python 3
• Blaming route decorator syntax
• Thinking Flask app init is wrong

5. You want to build a web app with user login, admin panel, and database management. Which framework should you choose and why?

hard

A. Flask, because it has built-in admin and user authentication

B. Django, because it provides built-in admin, user auth, and database tools

C. Flask, because it is heavier and has more features out of the box

D. Django, because it is lightweight and minimal for small apps

Solution

1. Step 1: Identify project needs

   The app needs user login, admin panel, and database management, which require many built-in features.

2. Step 2: Match framework features

   Django offers built-in admin interface, user authentication, and ORM for database management, making it ideal for this.

3. Final Answer:

   Django, because it provides built-in admin, user auth, and database tools -> Option B

4. Quick Check:

   Big apps with admin need Django [OK]

Hint: Big apps with admin? Choose Django [OK]

Common Mistakes:

• Choosing Flask for built-in admin features
• Thinking Flask is heavier than Django
• Confusing Django as minimal for small apps