073 Set Matrix Zeroes

class Solution:
    # @param {integer[][]} matrix
    # @return {void} Do not return anything, modify matrix in-place instead.
    def setZeroes(self, matrix):
        m = len(matrix)
        if m == 0:
            return matrix
        n = len(matrix[0])
        row, col = False, False
        for j in range(0 ,n):
            if matrix[0][j] == 0:
                row = True
                break
        for i in range(0,m):
            if matrix[i][0] == 0:
                col = True
                break
        for i in range(0, m):
            for j in range(0,n):
                if matrix[i][j] == 0:
                    matrix[i][0] = 0
                    matrix[0][j] = 0
        for i in range(1, m):
            for j in range(1,n):
                if matrix[i][0] == 0 or matrix[0][j] == 0:
                    matrix[i][j] = 0
        if row:
            for j in range(0 ,n):
                matrix[0][j] = 0
        if col:
            for i in range(0,m):
                matrix[i][0] = 0