```
zhu=set()
for i in xrange(9):
for j in xrange(9):
if board[i][j]!='.':
if (board[i][j],i) not in zhu and (j,board[i][j]) not in zhu and (board[i][j],i/3,j/3) not in zhu:
zhu.add((board[i][j],i))
zhu.add((j,board[i][j]))
zhu.add((board[i][j],i/3,j/3))
else:
return False
return True
```

by the way,is anyone can modify this line(if (board[i][j],i) not in zhu and (j,board[i][j]) not in zhu and (board[i][j],i/3,j/3) not in zhu), it's too long