Installed apps management in Django - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to add a new app named 'blog' to the installed apps list.

Django

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    [1]
]

Drag options to blanks, or click blank then click option'

A'blog',

B'blog'

Cblog

D'blog.apps.BlogConfig',

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting the comma after the app name

Not using quotes around the app name

Using the app name without quotes

In Django settings, apps are listed as strings with commas. Adding 'blog', (with comma) correctly adds the app.

2fill in blank

medium

Complete the code to import the settings module in a Django project.

Django

from django.conf import [1]

Drag options to blanks, or click blank then click option'

Aconfig

Bapps

Csettings

Dmodels

Attempts:

3 left

💡 Hint

Common Mistakes

Importing 'config' instead of 'settings'

Trying to import 'apps' or 'models' from django.conf

The Django settings module is imported from django.conf as 'settings'.

3fill in blank

hard

Fix the error in the code to check if 'blog' app is installed.

Django

if 'blog' [1] settings.INSTALLED_APPS:
    print('Blog app is installed')

Drag options to blanks, or click blank then click option'

Anot in

Bin

C==

Dis

Attempts:

3 left

💡 Hint

Common Mistakes

Using '==' to compare string with list

Using 'is' instead of 'in'

Using 'not in' when checking for presence

To check if an app is installed, use the 'in' keyword to see if it is in INSTALLED_APPS list.

4fill in blank

hard

Fill both blanks to add 'blog' app config class to INSTALLED_APPS.

Django

INSTALLED_APPS.append([1])
print([2][-1])

Drag options to blanks, or click blank then click option'

A'blog.apps.BlogConfig'

BINSTALLED_APPS

Csettings.INSTALLED_APPS

D'blog'

Attempts:

3 left

💡 Hint

Common Mistakes

Appending just 'blog' instead of full config path

Printing settings.INSTALLED_APPS instead of INSTALLED_APPS

Using wrong variable names

To add the app config class, append its string to INSTALLED_APPS list and print the last item from INSTALLED_APPS.

5fill in blank

hard

Fill all three blanks to create a dictionary of app names and their config classes from INSTALLED_APPS.

Django

app_dict = [1]( (app.split('.')[-1].replace('Config', '').lower(), app) for app in [2] if app.endswith([3]) )

Drag options to blanks, or click blank then click option'

Adict

BINSTALLED_APPS

C'Config'

Dlist

Attempts:

3 left

💡 Hint

Common Mistakes

Using list() instead of dict()

Using wrong variable name instead of INSTALLED_APPS

Not filtering apps by 'Config' suffix

This code builds a dictionary from INSTALLED_APPS filtering apps ending with 'Config'.

Practice

1. What is the main purpose of the INSTALLED_APPS setting in a Django project?

easy

A. To tell Django which apps to include and use in the project

B. To list all the URLs in the project

C. To configure the database connection

D. To set the static files directory

Solution

1. Step 1: Understand the role of INSTALLED_APPS

   This setting lists all apps Django should load and use in the project.

2. Step 2: Compare with other settings

   URL listing, database config, and static files are handled by other settings, not INSTALLED_APPS.

3. Final Answer:

   To tell Django which apps to include and use in the project -> Option A

4. Quick Check:

   Installed apps = apps Django uses [OK]

Hint: INSTALLED_APPS lists apps Django loads [OK]

Common Mistakes:

• Confusing INSTALLED_APPS with URL configuration
• Thinking INSTALLED_APPS sets database info
• Mixing INSTALLED_APPS with static files settings

2. Which of the following is the correct way to add a custom app named blog to the INSTALLED_APPS list in settings.py?

easy

A. 'blog.apps.BlogConfig',

B. 'blog.models.Blog',

C. 'blog.views',

D. 'blog.urls',

Solution

1. Step 1: Identify correct app config path

   Custom apps are added by referencing their AppConfig class, usually '<appname>.apps.<AppConfigClass>'.

2. Step 2: Check options

   Only 'blog.apps.BlogConfig', uses the correct pattern '<appname>.apps.<ConfigClass>'. Others point to models, views, or urls which are incorrect here.

3. Final Answer:

   'blog.apps.BlogConfig', -> Option A

4. Quick Check:

   AppConfig path = 'blog.apps.BlogConfig' [OK]

Hint: Add apps using their AppConfig path [OK]

Common Mistakes:

• Adding models or views instead of AppConfig
• Forgetting the trailing comma in the list
• Using app name only without '.apps.ConfigClass'

3. Given the following INSTALLED_APPS in settings.py:

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'myapp.apps.MyappConfig',
]

What will happen if you remove 'django.contrib.auth' from this list?

medium

A. No effect; Django will auto-add it

B. The admin site will stop working completely

C. Static files will not load

D. Authentication features like login and user management will stop working

Solution

1. Step 1: Understand role of 'django.contrib.auth'

   This app provides authentication features like login, logout, and user management.

2. Step 2: Effect of removing it

   Removing it disables authentication features but admin site depends on it indirectly; admin may partially work but auth features break.

3. Final Answer:

   Authentication features like login and user management will stop working -> Option D

4. Quick Check:

   Remove auth app = no login features [OK]

Hint: Auth app controls login; removing it breaks login [OK]

Common Mistakes:

• Assuming admin site fully breaks without auth
• Thinking static files depend on auth app
• Believing Django auto-adds missing apps

4. You added a new app shop to INSTALLED_APPS but after restarting the server, Django raises an error: ModuleNotFoundError: No module named 'shop'. What is the most likely cause?

medium

A. You forgot to add shop to urls.py

B. The shop app folder is missing or not in the project directory

C. You did not run python manage.py migrate

D. The shop app is not listed in INSTALLED_APPS

Solution

1. Step 1: Understand the error meaning

   ModuleNotFoundError means Python cannot find the app folder or module named 'shop'.

2. Step 2: Check common causes

   If the app folder is missing or not in the Python path, this error occurs. Forgetting URLs or migrations does not cause this error.

3. Final Answer:

   The shop app folder is missing or not in the project directory -> Option B

4. Quick Check:

   ModuleNotFoundError = missing app folder [OK]

Hint: ModuleNotFoundError means app folder missing [OK]

Common Mistakes:

• Confusing URL config errors with module errors
• Thinking migrations cause import errors
• Assuming INSTALLED_APPS omission causes ModuleNotFoundError

5. You have two apps, blog and shop, both added to INSTALLED_APPS. You want to disable the shop app temporarily without deleting it from the list. Which is the best way to do this?

hard

A. Set a variable SHOP_ENABLED = False in settings.py

B. Delete the shop app folder from the project

C. Comment out or remove 'shop.apps.ShopConfig' from INSTALLED_APPS and restart the server

D. Remove all URLs related to shop from urls.py

Solution

1. Step 1: Understand how Django loads apps

   Django loads apps listed in INSTALLED_APPS. Removing or commenting out disables the app.

2. Step 2: Evaluate options

   Deleting the folder removes code (not temporary). Removing URLs only hides routes but app still loads. Setting a variable does nothing unless app code checks it.

3. Final Answer:

   Comment out or remove 'shop.apps.ShopConfig' from INSTALLED_APPS and restart the server -> Option C

4. Quick Check:

   Remove from INSTALLED_APPS to disable app [OK]

Hint: Disable app by removing it from INSTALLED_APPS [OK]

Common Mistakes:

• Deleting app folder instead of disabling
• Only removing URLs but app still loads
• Setting unused flags in settings.py