No, not when I'm in Italy. It's not expected here. There's a series of complicated reasons for that - waiters receive a decent minimum wage, most restaurants are family-owned and therefore the waiter is often somebody who actually owns a piece of the restaurant, very very often the "service" is included in the final price to the tune of one or two euro per person, etc. etc.
You would tip if you're impressed with the place, but even then, it's not like there's a fixed percentage - rounding up the final number - like, having to pay 46 euro and paying with a 50 euro banknote and saying 'keep the change' - is considered perfectly fine and very polite already.
Italians are probably very unpopular in places where it's custom to leave a tip. I forgot about it a lot in Germany, even if I got it explained to me like four times.
Re: question
You would tip if you're impressed with the place, but even then, it's not like there's a fixed percentage - rounding up the final number - like, having to pay 46 euro and paying with a 50 euro banknote and saying 'keep the change' - is considered perfectly fine and very polite already.
Italians are probably very unpopular in places where it's custom to leave a tip. I forgot about it a lot in Germany, even if I got it explained to me like four times.