celery-once

import os from celery import Celery from celery_once import QueueOnce # Configure Celery app app = Celery('my_app', broker='redis://localhost:6379/0', backend='redis://localhost:6379/0') # Configure celery-once backend (e.g., Redis) # Set CELERY_ONCE in your Celery config, or directly in app.conf app.conf.update( CELERY_ONCE = { 'backend': 'celery_once.backends.Redis', # or 'celery_once.backends.File' 'default_timeout': 60 * 60 # 1 hour default lock timeout } ) @app.task(base=QueueOnce) def my_unique_task(arg1, arg2): """This task will only run once at a time globally.""" print(f"Executing my_unique_task with {arg1}, {arg2}") return f"Task completed for {arg1}, {arg2}" if __name__ == '__main__': # Example usage (usually tasks are called by Celery workers) # To run this, you'd typically start a Celery worker: celery -A your_module_name worker -l info # And then call the task from another Python script or shell: # from your_module_name import my_unique_task # my_unique_task.delay('value1', 'value2') # my_unique_task.delay('value1', 'value2') # This second call will be skipped if the first is still locked # For demonstration, manually calling (won't use Celery broker in this snippet directly) print("To run tasks, ensure Redis is running and start a Celery worker.\n") print("Example: my_unique_task.delay('hello', 123) will queue the task.\n") print("If run twice quickly, the second will be skipped (depending on backend).")