```
class Solution(object):
def isValidSudoku(self, board):
"""
:type board: List[List[str]]
:rtype: bool
"""
#check row
for i in board:
tmp=[]
for j in i:
if j in tmp:
return False
if j!='.':
tmp.append(j)
#check col
for i in range(9):
tmp=[]
for j in board:
if j[i] in tmp:
return False
if j[i]!='.':
tmp.append(j[i])
#check cell
tmp=[[[],[],[]],[[],[],[]],[[],[],[]]]
for i in range(9):
for j in range(9):
if board[i][j]=='.':
continue
elif board[i][j] in tmp[i/3][j/3]:
return False
else:
tmp[i/3][j/3].append(board[i][j])
return True
```