That's cheating! It's using two different kinds of by here. da and presso have different meanings.
Not sure if this sounds stupid, but how do I know what 'da' means when I've seen it translated as since/from/to/of/by?
It's ridiculous to try to translate a phrase like this w/out any context. Depending on where/how it's used, this could be translated in any number of different ways. Wish duo would give us CONVERSATIONS to translate!
"Not by us" would always be "Non da noi" in Italian. It wouldn't work the other way round, unfortunately.