python

SQLAlchemy stale data during flush

sqlalchemy\.orm\.exc\.StaleDataError

Fixes

1.Refresh the instance with session.refresh(obj) before modifying
2.Use optimistic locking with version_id_col
3.Handle concurrent modifications with retry logic

sqlalchemyconcurrency

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