python

SQLAlchemy duplicate identity in session

sqlalchemy\.exc\.InvalidRequestError.*Can't attach instance.*another instance with key.*already present

Fixes

1.Use session.merge() to reconcile with existing identity
2.Query for existing record first: session.get(Model, id)
3.Expunge the conflicting instance before adding the new one

sqlalchemyidentity-map

Related Errors

Asyncio event loop already running

RuntimeError: This event loop is already running

•Use nest_asyncio.apply() to allow nested event loops
•Use asyncio.run_coroutine_threadsafe() instead of asyncio.run()

Coroutine never awaited

RuntimeWarning: coroutine '.*' was never awaited

•Add 'await' before the coroutine call
•Use asyncio.create_task() to schedule the coroutine

Asyncio task was cancelled

asyncio\.CancelledError

•Handle CancelledError in try/except within the task
•Use asyncio.shield() to protect critical sections from cancellation