howt o make sure its a valid sudoku in python
def check(sud):
zippedsud = zip(*sud)
boxedsud=[]
for li,line in enumerate(sud):
for box in range(3):
if not li % 3: boxedsud.append([]) # build a new box every 3 lines
boxedsud[box + li/3*3].extend(line[box*3:box*3+3])
for li in range(9):
if [x for x in [set(sud[li]), set(zippedsud[li]), set(boxedsud[li])] if x != set(range(1,10))]:
return False
return True