python

FastAPI response contains non-serializable object

TypeError: Object of type .* is not JSON serializable.*FastAPI

Fixes

1.Add custom JSON encoder via json_encoders in model Config
2.Use jsonable_encoder() from fastapi.encoders before returning
3.Implement __json__ or use Pydantic model for the response

fastapiserialization

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