Session framework configuration in Django - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

What is the default session engine in Django?

Django supports multiple session engines. Which one is used by default if you do not change any settings?

A django.contrib.sessions.backends.signed_cookies

B django.contrib.sessions.backends.db

C django.contrib.sessions.backends.file

D django.contrib.sessions.backends.cache

💡 Hint

Think about where Django stores session data by default.

The default session engine stores session data in the database using the django.contrib.sessions.backends.db backend.

❓ component_behavior

intermediate

What happens if SESSION_COOKIE_AGE is set to 0?

In Django settings, if you set SESSION_COOKIE_AGE = 0, what will be the behavior of the session cookie?

A The session cookie will expire immediately and not be saved.

B The session cookie will last for the default 2 weeks.

C The session cookie will never expire.

D The session cookie will expire when the browser is closed.

💡 Hint

Think about what a zero age means for cookies.

Setting SESSION_COOKIE_AGE to 0 makes the session cookie a browser-length cookie, which expires when the browser closes.

📝 Syntax

advanced

Identify the correct way to configure a cache-based session engine

Which of the following settings correctly configures Django to use the cache session engine?

A SESSION_ENGINE = 'django.contrib.sessions.backends.cache'

B SESSION_ENGINE = 'django.contrib.sessions.cache_backend'

C SESSION_ENGINE = 'django.sessions.backends.cache'

D SESSION_ENGINE = 'django.contrib.cache.sessions'

💡 Hint

Check the exact module path for the cache session backend.

The correct setting for cache-based sessions is django.contrib.sessions.backends.cache.

🔧 Debug

advanced

Why does session data not persist across requests?

A developer sets SESSION_ENGINE = 'django.contrib.sessions.backends.signed_cookies' but notices session data is lost after each request. What is the most likely cause?

A The SECRET_KEY setting is missing or not set properly.

B The database migrations for sessions were not run.

C The cache backend is not configured.

D The SESSION_COOKIE_AGE is set too high.

💡 Hint

Signed cookies require a secret to sign the data.

Signed cookie sessions require a properly set SECRET_KEY to sign and verify session data. Without it, session data cannot persist.

❓ state_output

expert

What is the output of this Django session code snippet?

Consider this Django view code snippet:

def view(request):
    request.session['count'] = request.session.get('count', 0) + 1
    return HttpResponse(str(request.session['count']))

If a user visits this view 3 times in the same browser session, what will be the output on the third visit?

Django

def view(request):
    request.session['count'] = request.session.get('count', 0) + 1
    return HttpResponse(str(request.session['count']))

A 1

B 2

C 3

D Error: 'count' key not found

💡 Hint

The session stores the count and increments it each visit.

Each visit increments the 'count' in the session by 1. On the third visit, the count will be 3.

Practice

1. What is the main purpose of Django's session framework?

easy

A. To store static files like images and CSS

B. To handle database migrations automatically

C. To remember user data between different pages

D. To manage user authentication only

Solution

1. Step 1: Understand session framework role

   Django sessions store data to keep track of users as they move between pages.

2. Step 2: Compare options with session purpose

   Only To remember user data between different pages describes remembering user data between pages, which is the session's job.

3. Final Answer:

   To remember user data between different pages -> Option C

4. Quick Check:

   Sessions remember users = B [OK]

Hint: Sessions remember users across pages, not files or migrations [OK]

Common Mistakes:

• Confusing sessions with static file storage
• Thinking sessions only handle login
• Mixing sessions with database migrations

2. Which setting in settings.py specifies the backend storage for sessions?

easy

A. SESSION_ENGINE

B. SESSION_COOKIE_AGE

C. SESSION_SAVE_EVERY_REQUEST

D. SESSION_EXPIRE_AT_BROWSER_CLOSE

Solution

1. Step 1: Identify session backend setting

   The setting that controls where sessions are stored is SESSION_ENGINE.

2. Step 2: Review other options

   Other options control cookie age, saving behavior, or expiration, not storage backend.

3. Final Answer:

   SESSION_ENGINE -> Option A

4. Quick Check:

   Backend storage = SESSION_ENGINE [OK]

Hint: SESSION_ENGINE sets storage backend, not cookie or expiration [OK]

Common Mistakes:

• Confusing SESSION_ENGINE with cookie age
• Mixing save behavior with storage backend
• Assuming expiration settings control storage

3. Given this settings.py snippet:

SESSION_ENGINE = 'django.contrib.sessions.backends.cache'
SESSION_COOKIE_AGE = 1209600  # 2 weeks
SESSION_EXPIRE_AT_BROWSER_CLOSE = False

What happens when a user closes and reopens their browser?

medium

A. The session cookie is deleted but data remains in cache

B. The session expires immediately on browser close

C. The session is stored in the database and expires on logout

D. The session is kept for 2 weeks and user stays logged in

Solution

1. Step 1: Analyze SESSION_EXPIRE_AT_BROWSER_CLOSE

   It is set to False, so session cookies do not expire when browser closes.

2. Step 2: Check SESSION_COOKIE_AGE

   Set to 2 weeks, so session lasts that long unless user logs out.

3. Final Answer:

   The session is kept for 2 weeks and user stays logged in -> Option D

4. Quick Check:

   Expire at close = False means session kept [OK]

Hint: False expire at close means session lasts cookie age [OK]

Common Mistakes:

• Assuming session expires on browser close by default
• Confusing cache backend with database storage
• Thinking cookie deletion removes session data immediately

4. You set SESSION_ENGINE = 'django.contrib.sessions.backends.file' but get errors about missing directories. What is the likely cause?

medium

A. The session file directory does not exist or lacks write permission

B. SESSION_ENGINE value is invalid and causes syntax error

C. You forgot to add sessions to INSTALLED_APPS

D. SESSION_COOKIE_AGE is set too low causing session loss

Solution

1. Step 1: Understand file backend requirements

   The file backend stores sessions in files, needing a writable directory.

2. Step 2: Identify cause of errors

   If directory is missing or not writable, errors occur when saving sessions.

3. Final Answer:

   The session file directory does not exist or lacks write permission -> Option A

4. Quick Check:

   File backend needs writable directory [OK]

Hint: File backend needs writable folder, else errors occur [OK]

Common Mistakes:

• Assuming SESSION_ENGINE value syntax is wrong
• Forgetting sessions are built-in, no INSTALLED_APPS needed
• Blaming cookie age for file write errors

5. You want sessions to expire when the user closes the browser but also want to keep sessions for 1 hour if the browser stays open. Which settings combination achieves this?

hard

A. SESSION_EXPIRE_AT_BROWSER_CLOSE = False and SESSION_COOKIE_AGE = 3600

B. SESSION_EXPIRE_AT_BROWSER_CLOSE = True and SESSION_COOKIE_AGE = 3600

C. SESSION_EXPIRE_AT_BROWSER_CLOSE = True and SESSION_COOKIE_AGE = None

D. SESSION_EXPIRE_AT_BROWSER_CLOSE = False and SESSION_COOKIE_AGE = None

Solution

1. Step 1: Understand SESSION_EXPIRE_AT_BROWSER_CLOSE

   Setting it to True makes the session expire when browser closes.

2. Step 2: Understand SESSION_COOKIE_AGE

   Setting it to 3600 seconds (1 hour) limits session lifetime if browser stays open.

3. Final Answer:

   SESSION_EXPIRE_AT_BROWSER_CLOSE = True and SESSION_COOKIE_AGE = 3600 -> Option B

4. Quick Check:

   Expire at close True + 1 hour age = A [OK]

Hint: Expire at close True + cookie age limits session time [OK]

Common Mistakes:

• Setting expire at close False when wanting session to end on close
• Using None for cookie age disables expiration
• Confusing cookie age with session storage backend