pyobjc-framework-coredata

import CoreData import objc import os # 1. Define the Managed Object Model programmatically model = CoreData.NSManagedObjectModel.alloc().init() entity = CoreData.NSEntityDescription.alloc().init() entity.name = "Event" entity.managedObjectClassName = "Event" attribute_name = CoreData.NSAttributeDescription.alloc().init() attribute_name.name = "name" attribute_name.attributeType = CoreData.NSStringAttributeType attribute_name.optional = False attribute_timestamp = CoreData.NSAttributeDescription.alloc().init() attribute_timestamp.name = "timestamp" attribute_timestamp.attributeType = CoreData.NSDateAttributeType attribute_timestamp.optional = False entity.properties = [attribute_name, attribute_timestamp] model.entities = [entity] # 2. Create a Persistent Container # Use a unique in-memory store for a quick runnable example container = CoreData.NSPersistentContainer.alloc().initWithName_managedObjectModel_( "MyCoreDataApp", model ) # Configure an in-memory store for the quickstart store_description = CoreData.NSPersistentStoreDescription.alloc().init() store_description.URL = None # For in-memory store store_description.type = CoreData.NSInMemoryStoreType container.persistentStoreDescriptions = [store_description] def load_stores(completion_handler): container.loadPersistentStoresWithCompletionHandler_(completion_handler) # Convert Python function to an Objective-C block using objc.block # This is necessary because loadPersistentStoresWithCompletionHandler_ expects an Objective-C block @objc.block def store_load_handler(store_description, error): if error: print(f"Failed to load persistent store: {error}") else: print(f"Successfully loaded store: {store_description.URL().path()}") # 3. Get the Managed Object Context context = container.viewContext # 4. Create and Save an NSManagedObject Event = context.persistentStoreCoordinator().managedObjectModel().entitiesByName().get("Event") new_event = CoreData.NSManagedObject.alloc().initWithEntity_insertIntoManagedObjectContext_( Event, context ) new_event.setValue_forKey_("Python Demo Event", "name") new_event.setValue_forKey_(CoreData.NSDate.date(), "timestamp") # Save changes to the context (which saves to the store) try: context.save() print(f"Saved new event: {new_event.name()} at {new_event.timestamp()}") except Exception as e: print(f"Error saving context: {e}") # 5. Fetch NSManagedObjects fetch_request = CoreData.NSFetchRequest.fetchRequestWithEntityName_("Event") events = context.executeFetchRequest_error_(fetch_request, objc.NULL) if events: print("Fetched Events:") for event_obj in events: print(f" - Name: {event_obj.name()}, Timestamp: {event_obj.timestamp()}") else: print("No events found.") load_stores(store_load_handler) # To keep the application running for asynchronous operations (if not in a GUI app) # For simple script, this might not be strictly needed as the completion handler finishes sync if in-memory. # In a real app, you'd use NSApplication.run() or similar.