As far as I know you only get a ticket if you're actually parked there when the sweeper comes by. There's a parking cop car following the sweeper and ticketing the cars. You're allowed to re-park in the street after the sweeper has done its job, even if it's still technically street sweeping time.
So if you've got a ticket, there almost certainly was a sweeper that came by at that time.
Pretty sure it varies depending on where you live. iirc When I was in SF the tickets would get distributed ahead of time and the sweeper would follow within an hour or so. Once the sweeper went by you were free to re-park.
In Oakland, there are different vehicles that come by for different purposes. As I understand it there’s an agitator, sprayer, and sweeper. You have to know when the whole process is complete, so I understand it’s easier just to avoid for the whole window.
The parking enforcement happens before the street sweeper comes. There’s usually four or five of them and they’re several blocks ahead of the sweeper. They’ll all stop and wait 20 minutes for the sweeper to catch up and refill water at the hydrant before continuing on.
So if you've got a ticket, there almost certainly was a sweeper that came by at that time.