Get It Done, Preet

After weeks of anticipation — and an intensive eight hours of preparation over the previous two days with his lawyers — Mayor de Blasio was finally grilled Friday by US Attorney Preet Bharara’s anticorruption team.

This follows earlier questioning by Manhattan DA Cy Vance’s office — which, like the feds, is looking into the possible sale of political favors to de Blasio’s donors.

Now it’s up to both prosecutors to bring this year-long investigation to a swift conclusion, one way or the other.

Yes, we understand that the feds’ probe in recent days has moved in some entirely new directions, one of them an outgrowth of the investigation of since-indicted Nassau County Executive Ed Mangano. Indeed, new leads apparently led Bharara’s office to delay Friday’s questioning by two weeks.

And we’re not suggesting that either Bharara or Vance take any shortcuts or skip any necessary steps.

But New Yorkers deserve to see a resolution as quickly as possible and not have it hanging over this year’s election.

All sides were predictably tight-lipped after the four-hour interrogation — to which the notoriously tardy mayor actually arrived a half-hour early.

And once it was over, it was back to politics as usual for de Blasio: Trying yet again to raise his national profile, the mayor jetted off to Atlanta to lobby for Keith Ellison, to be the next Democratic chairman.

But the new investigations are troubling — mostly because they follow the same old pattern: major donors to de Blasio’s campaign or nonprofit who appear to have gotten special attention from City Hall for their issues before city government.

Fairness requires holding off on judgment until the investigation is completed, no matter how suspicious things look.

But fairness to the people requires both thoroughness — and a timely finish.