def busses():
 return (Bus(g) for (k, g) in groupby(sorted(core.find(find_all=True), key=(lambda d: d.bus)), (lambda d: d.bus)))

def busses ( ) : return ( Bus ( g ) for ( k , g ) in groupby ( sorted ( core . find ( find_all = True ) , key = ( lambda d : d . bus ) ) , ( lambda d : d . bus ) ) )
returns a tuple with the usb busses .