the error seems like what would happen right now, sure. we have a complete doc section now on setting up event handlers with async objects:
https://docs.sqlalchemy.org/en/14/orm/extensions/asyncio.html#using-events-with-the-asyncio-extension On Thu, Feb 24, 2022, at 2:56 PM, Brendan Blanchard wrote: > Hi all, > > I've been having a lot of fun trying to optimize an async data retrieval > system, but am in need of tracking when connections are checked in and out so > I can debug overloading the connection pool. The documentation was of course > helpful in the synchronous case for adding listeners on 'checkin' and > 'checkout', but not so much for async. > > I finally came across this SO post > <https://stackoverflow.com/questions/67874092/sqlalchemy-1-4-async-event-listeners> > where the OP was getting a helpful error message stating that async > listeners were not supported, and to use `{async_engine}.sync_engine` to > register listeners to (which solves my problem, too), but wanted to check in > about the error I'm getting instead. With SQLAlchemy 1.4.29 on Python 3.10 > (with asyncpg), the following produces a cryptic traceback rather than a > pointed error message. Is this a consequence of partial support for async > listeners at this time? > > """ > async_engine = create_async_engine(...) > Session = sessionmaker(bind=async_engine, class_=AsyncSession) > > @event.listens_for(async_engine, 'checkout') > def receive_checkout(dbapi_connection, connection_record, connection_proxy): > print(f'Session checked out at {datetime.now()}') > print(f'\t{dbapi_connection}') > print(f'\t{connection_record}') > print(f'\t{connection_proxy}') > > async with Session() as session: > result = await session.execute( > text('SELECT version();') > ) > > print(result.scalar()) > """ > > """ > Error Traceback (most recent call last): > File > "/home/brendan/PycharmProjects/db_utils/venv/lib/python3.10/site-packages/sqlalchemy/event/base.py", > line 104, in __getattr__ > ls = self._empty_listeners[name] > KeyError: 'checkout' > > During handling of the above exception, another exception occurred: > > Traceback (most recent call last): > File "/home/brendan/PycharmProjects/db_utils/test/test_database.py", line > 153, in test_listeners_on_async_engine > asyncio.run(self.run_test_listeners_on_async_engine()) > File "/usr/lib/python3.10/asyncio/runners.py", line 44, in run > return loop.run_until_complete(main) > File "/usr/lib/python3.10/asyncio/base_events.py", line 641, in > run_until_complete > return future.result() > File "/home/brendan/PycharmProjects/db_utils/test/test_database.py", line > 139, in run_test_listeners_on_async_engine > def recieve_checkout(dbapi_connection, connection_record, > connection_proxy): > File > "/home/brendan/PycharmProjects/db_utils/venv/lib/python3.10/site-packages/sqlalchemy/event/api.py", > line 160, in decorate > listen(target, identifier, fn, *args, **kw) > File > "/home/brendan/PycharmProjects/db_utils/venv/lib/python3.10/site-packages/sqlalchemy/event/api.py", > line 115, in listen > _event_key(target, identifier, fn).listen(*args, **kw) > File > "/home/brendan/PycharmProjects/db_utils/venv/lib/python3.10/site-packages/sqlalchemy/event/registry.py", > line 213, in listen > dispatch_collection = getattr(target.dispatch, identifier) > File > "/home/brendan/PycharmProjects/db_utils/venv/lib/python3.10/site-packages/sqlalchemy/event/base.py", > line 106, in __getattr__ > raise AttributeError(name) > AttributeError: checkout > """ > > I'm happy to contribute to documentation if it'll be of any help. > > Cheers, > Brendan > > > -- > SQLAlchemy - > The Python SQL Toolkit and Object Relational Mapper > > http://www.sqlalchemy.org/ > > To post example code, please provide an MCVE: Minimal, Complete, and > Verifiable Example. See http://stackoverflow.com/help/mcve for a full > description. > --- > You received this message because you are subscribed to the Google Groups > "sqlalchemy" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to sqlalchemy+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/sqlalchemy/71f69936-7f0d-419d-8350-664ee296da61n%40googlegroups.com > > <https://groups.google.com/d/msgid/sqlalchemy/71f69936-7f0d-419d-8350-664ee296da61n%40googlegroups.com?utm_medium=email&utm_source=footer>. -- SQLAlchemy - The Python SQL Toolkit and Object Relational Mapper http://www.sqlalchemy.org/ To post example code, please provide an MCVE: Minimal, Complete, and Verifiable Example. See http://stackoverflow.com/help/mcve for a full description. --- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To unsubscribe from this group and stop receiving emails from it, send an email to sqlalchemy+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/sqlalchemy/9b06c9c3-f123-4adf-9a93-10f3aef2ecb9%40www.fastmail.com.
