73 leetcode - Set Matrix Zeroes

#!/usr/bin/python
# -*- coding: utf-8 -*-
'''
Set Matrix Zeroes.
Given a m x n matrix, if an element is 0, set its entire row and column to 0. Do it in place.
'''
class Solution(object):
    def setZeroes(self, matrix):
        """
        :type matrix: List[List[int]]
        :rtype: void Do not return anything, modify matrix in-place instead.
        """
        row_len = len(matrix)
        if row_len == 0:
            return
        col_len = len(matrix[0])
        if col_len == 0:
            return
        in_place = []
        for row,row_val in enumerate(matrix):
            for col,val in enumerate(row_val):
                if val == 0:
                    in_place.append((row,col))

        for i in in_place:
            for index in range(row_len):
                matrix[index][i[1]] = 0
            for index in range(col_len):
                matrix[i[0]][index] = 0

if __name__ == "__main__":
    s = Solution()
    m = [[1,2],[1,2]]
    s.setZeroes(m)
    print m