[...] in this case means "details omitted for clarity". For example, the tutorial example here would actually produce output like
2022-08-15 12:00:20,656 INFO sqlalchemy.engine.Engine BEGIN (implicit)
2022-08-15 12:00:20,658 INFO sqlalchemy.engine.Engine select 'hello world'
2022-08-15 12:00:20,658 INFO sqlalchemy.engine.Engine [generated in 0.00061s] ()
[('hello world',)]
2022-08-15 12:00:20,659 INFO sqlalchemy.engine.Engine ROLLBACK
but the [generated in 0.00061s] clutters things up so the tutorial omits it
BEGIN (implicit)
select 'hello world'
[...] ()
[('hello world',)]
ROLLBACK
As for the (), they show that no parameters were passed. If the query had been parameterized, e.g.,
result = conn.execute(sa.text("select :hello"), dict(hello='Howdy!'))
then the tutorial would have displayed
select ?
[...] ('Howdy!',)