django-guardian

import os from django.conf import settings from django.contrib.auth.models import User from guardian.shortcuts import assign_perm, get_objects_for_user # Minimal Django settings setup for demonstration if not settings.configured: settings.configure( INSTALLED_APPS=[ 'django.contrib.auth', 'django.contrib.contenttypes', 'guardian', 'myapp' # assuming a minimal app that defines a 'Book' model ], DATABASES={'default': {'ENGINE': 'django.db.backends.sqlite3', 'NAME': ':memory:'}}, AUTHENTICATION_BACKENDS=( 'django.contrib.auth.backends.ModelBackend', 'guardian.backends.ObjectPermissionBackend', ), ANONYMOUS_USER_NAME = 'AnonymousUser', # Important for anonymous user support SECRET_KEY=os.environ.get('DJANGO_SECRET_KEY', 'a-very-secret-key-for-dev'), DEBUG=True ) # In a real project, this would be in models.py from django.db import models class Book(models.Model): title = models.CharField(max_length=255) author = models.ForeignKey(User, on_delete=models.CASCADE, related_name='authored_books', null=True) def __str__(self): return self.title class Meta: permissions = ( ('view_book', 'Can view book'), ('edit_book', 'Can edit book'), ) # --- Example Usage --- # Assume database is set up and migrations run (e.g., via `./manage.py migrate`) # This is a simplified representation for demonstration. # Create users and an object user1 = User.objects.create_user(username='alice', password='password123') user2 = User.objects.create_user(username='bob', password='password123') book1 = Book.objects.create(title='The Great Adventure', author=user1) book2 = Book.objects.create(title='Python Mastery', author=user2) print(f"\nBook 1: {book1.title} by {book1.author}") print(f"Book 2: {book2.title} by {book2.author}") # Assign 'view_book' permission to user1 for book1 assign_perm('view_book', user1, book1) print(f"\nAssigned 'view_book' to {user1.username} for {book1.title}") # Check permissions print(f"{user1.username} can view book1: {user1.has_perm('view_book', book1)}") print(f"{user2.username} can view book1: {user2.has_perm('view_book', book1)}") # Assign 'edit_book' permission to user1 for book2 assign_perm('edit_book', user1, book2) print(f"Assigned 'edit_book' to {user1.username} for {book2.title}") # Get objects user1 has 'view_book' permission for user1_viewable_books = get_objects_for_user(user1, 'view_book', klass=Book) print(f"\n{user1.username} can view: {[b.title for b in user1_viewable_books]}") # Get objects user1 has 'edit_book' permission for user1_editable_books = get_objects_for_user(user1, 'edit_book', klass=Book) print(f"{user1.username} can edit: {[b.title for b in user1_editable_books]}")