Petworth isn’t a great pick for you because of the layout of the metro lines. Although getting to AU by car would be quick, the metro layout requires you to ride the green line downtown, switch to the red line and then ride it back north, essentially making a giant u turn.
The neighborhood has changed a lot, there is a big CVS at the metro and a large apt. building with shops opening on the ground floor. It is the same developer who did U Street corridor. It is also overrun with hipsters in the past couple of years, changing (for the worse, IMHO) the character of the neighborhood.
Yes, and there’s a 7-11 by the Cleveland Park metro - what’s your point? 
Seriously, Fractured Prune is so far beyond Krispy Kreme in terms of deliciousness it isn’t even funny. Imagine a fresh, hot donut covered in real honey and cinammon sugar … drools.
This is the Beltway donut hierarchy, in a nutshell:
Fractured Prune > Krispy Kreme > a poke in the eye with a sharp stick > Dunkin’ Donuts.
If it helps broaden the search at all–
Georgetown’s law school is a couple blocks from Union Station. Georgetown provides an oft-running direct shuttle between the law school and main campus.
FWIW, I loved living on Capital Hill. Was there for a couple years before law school and a bit afterwards. Fantastic for visitors (I was a few blocks from the Capital), and the daily walk to school was wonderful. The walk to Union Station and Eastern Market easily put me in reach of most of the metro-accessible city.
Speaking of Union Station, has anyone been to the downstairs food court recently? Is that “yummy yummy; good for your tummy!” dude still there?
There’s also a Fractured Prune in Silver Spring too.
Ugh, the G.U.T.S. shuttle from the law school to main campus takes a year and a half. I’d never depend on it for regular transit.