Built-in permission system in Django - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the Django permission model.

Django

from django.contrib.auth.models import [1]

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

AUser

BGroup

CSession

DPermission

Attempts:

3 left

💡 Hint

Common Mistakes

Importing User instead of Permission

Importing Group or Session which are unrelated here

The Permission model is used to manage built-in permissions in Django.

2fill in blank

medium

Complete the code to check if a user has a specific permission.

Django

if user.[1]('app_label.permission_codename'):

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

Acan

Bcheck_perm

Chas_perm

Dis_allowed

Attempts:

3 left

💡 Hint

Common Mistakes

Using non-existent methods like check_perm or can

Confusing with group membership checks

The has_perm method checks if a user has a given permission string.

3fill in blank

hard

Fix the error in the code to assign a permission to a user.

Django

permission = Permission.objects.get(codename='add_article')
user.user_permissions.[1](permission)

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

Aassign

Badd

Cremove

Dset

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'assign' which is not a valid method

Using 'remove' which deletes permissions

The add method adds a permission to the user's permissions.

4fill in blank

hard

Fill both blanks to create a dictionary comprehension of permissions with their names.

Django

{perm.[1]: perm.[2] for perm in Permission.objects.all()}

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

Acodename

Bname

Cid

Dcontent_type

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'id' or 'content_type' as keys or values

Mixing up codename and name

The codename is the key and name is the value for permissions.

5fill in blank

hard

Fill all three blanks to filter permissions for a specific app and order by name.

Django

permissions = Permission.objects.filter(content_type__app_label=[1]).order_by([2]).values_list([3], flat=True)

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

A'blog'

B'name'

C'codename'

D'id'

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong app label string

Ordering by codename instead of name

Getting wrong field in values_list

Filter by app label 'blog', order by 'name', and get list of 'codename's.

Practice

1. What is the purpose of Django's built-in permission system?

easy

A. To control what actions users can perform in the application

B. To manage database migrations automatically

C. To style the user interface with CSS

D. To optimize query performance

Solution

1. Step 1: Understand the role of permissions

   Django's permission system is designed to control user access and actions within the app.

2. Step 2: Eliminate unrelated options

   Options about migrations, styling, and query optimization are unrelated to permissions.

3. Final Answer:

   To control what actions users can perform in the application -> Option A

4. Quick Check:

   Permission system controls user actions = D [OK]

Hint: Permissions control user actions, not database or styling [OK]

Common Mistakes:

• Confusing permissions with database migrations
• Thinking permissions handle UI styling
• Assuming permissions optimize queries

2. Which of the following is the correct way to check if a user has a permission in Django?

easy

A. user.permission('app_label.permission_codename')

B. user.check_permission('app_label.permission_codename')

C. user.has_perm('app_label.permission_codename')

D. user.can('app_label.permission_codename')

Solution

1. Step 1: Recall Django's permission check method

   The correct method to check permissions is has_perm on the user object.

2. Step 2: Verify method names

   Other options like check_permission, permission, or can do not exist in Django's user model.

3. Final Answer:

   user.has_perm('app_label.permission_codename') -> Option C

4. Quick Check:

   Use has_perm() to check permissions = A [OK]

Hint: Remember: user.has_perm() is the official permission check [OK]

Common Mistakes:

• Using incorrect method names like check_permission
• Trying to call permission as a property
• Assuming 'can' method exists on user

3. Given the following code snippet, what will be the output if the user has the permission 'blog.add_post'?

if user.has_perm('blog.add_post'):
    print('Permission granted')
else:
    print('Permission denied')

medium

A. Permission granted

B. Error: has_perm method not found

C. Permission denied

D. No output

Solution

1. Step 1: Understand the has_perm method behavior

   If the user has the permission 'blog.add_post', has_perm returns True.

2. Step 2: Follow the if-else logic

   Since has_perm returns True, the code prints 'Permission granted'.

3. Final Answer:

   Permission granted -> Option A

4. Quick Check:

   has_perm True prints 'Permission granted' = C [OK]

Hint: True from has_perm means permission granted message [OK]

Common Mistakes:

• Assuming has_perm returns False incorrectly
• Expecting an error from has_perm method
• Thinking no output occurs

4. Identify the error in this code snippet that checks user permissions:

if user.has_perm('blog.add_post'):
print('Allowed')
else:
print('Denied')

medium

A. Incorrect permission codename format

B. Using print instead of return

C. has_perm method does not exist on user

D. Missing indentation inside if and else blocks

Solution

1. Step 1: Check Python syntax rules for blocks

   Python requires indentation inside if and else blocks to define their scope.

2. Step 2: Identify the missing indentation

   The print statements are not indented, causing a syntax error.

3. Final Answer:

   Missing indentation inside if and else blocks -> Option D

4. Quick Check:

   Python needs indentation in blocks = B [OK]

Hint: Always indent code inside if/else blocks in Python [OK]

Common Mistakes:

• Ignoring indentation errors
• Thinking permission codename format is wrong
• Assuming has_perm method is missing
• Confusing print with return in this context

5. You want to assign the permission 'polls.change_vote' to a group named 'Editors'. Which is the correct way to do this in Django?

hard

A. group = Group.objects.create(name='Editors')
permission = Permission.objects.filter(codename='change_vote')
group.add_permission(permission)

B. group = Group.objects.get(name='Editors')
permission = Permission.objects.get(codename='change_vote', content_type__app_label='polls')
group.permissions.add(permission)

C. group = Group.get(name='Editors')
permission = Permission.get(codename='change_vote')
group.permissions.append(permission)

D. group = Group.objects.get(name='Editors')
permission = Permission.objects.get(name='change_vote')
group.permissions.add(permission)

Solution

1. Step 1: Retrieve the existing group and permission correctly

   Use Group.objects.get(name='Editors') to get the group. Use Permission.objects.get with codename and content_type__app_label to get the exact permission.

2. Step 2: Add the permission to the group's permissions

   Use group.permissions.add(permission) to assign the permission.

3. Final Answer:

   group = Group.objects.get(name='Editors') permission = Permission.objects.get(codename='change_vote', content_type__app_label='polls') group.permissions.add(permission) -> Option B

4. Quick Check:

   Use get() and add() with correct filters = A [OK]

Hint: Use get() with codename and add() to assign permission [OK]

Common Mistakes:

• Using create() instead of get() for existing group
• Using filter() without get() for single permission
• Wrong method names like add_permission or append
• Using name instead of codename for permission lookup