# create a hash of keys by key_id
keys_by_id = dict ( [ ( key['key_id'], key ) for key in keys ] )
# create a dict person_id -> [ (plc)keys ]
# create a hash of keys by key_id
keys_by_id = dict ( [ ( key['key_id'], key ) for key in keys ] )
# create a dict person_id -> [ (plc)keys ]