Session framework configuration in Django - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of Django's session framework?

Django's session framework stores and retrieves data on a per-site-visitor basis. It lets you keep information about users across requests without requiring them to log in.

beginner

Where do you configure the session engine in a Django project?

You configure the session engine in the settings.py file using the SESSION_ENGINE setting.

intermediate

Name two built-in session backends provided by Django.

Django provides several session backends, including:
- django.contrib.sessions.backends.db (database-backed sessions)
- django.contrib.sessions.backends.cache (cache-backed sessions)

beginner

How does Django identify a user's session across requests?

Django uses a session ID stored in a cookie named sessionid on the user's browser. This ID links the user to their session data on the server.

intermediate

What setting controls the duration a session lasts before expiring in Django?

The SESSION_COOKIE_AGE setting controls how long a session cookie lasts in seconds. By default, it is set to 1209600 seconds (2 weeks).

Which setting in Django specifies the backend used to store session data?

A SESSION_ENGINE

B SESSION_BACKEND

C SESSION_STORE

D SESSION_HANDLER

The correct setting is SESSION_ENGINE. It defines which backend Django uses to save session data.

By default, where does Django store session data?

A In browser local storage

B In the database

C In a file on the server

D In the cache only

By default, Django stores session data in the database using the django.contrib.sessions.backends.db backend.

What cookie name does Django use to track sessions by default?

A django_session

B user_session

C sessid

D sessionid

Django uses the cookie named sessionid to store the session ID.

Which setting controls how long a session cookie lasts before expiring?

A SESSION_COOKIE_AGE

B SESSION_TIMEOUT

C SESSION_EXPIRY

D SESSION_LIFETIME

The SESSION_COOKIE_AGE setting defines the duration in seconds for session cookie expiration.

If you want to store session data in cache instead of the database, which backend should you use?

A django.contrib.sessions.backends.file

B django.contrib.sessions.backends.db

C django.contrib.sessions.backends.cache

D django.contrib.sessions.backends.signed_cookies

To store sessions in cache, use django.contrib.sessions.backends.cache as the session engine.

Explain how Django's session framework works to keep track of user data across requests.

Think about how the browser and server share information to remember a user.

Describe how to change the session storage backend in a Django project and why you might want to do that.

Consider different ways to store session data and their pros and cons.

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