Leetcode 1861. Rotating the Box

class Solution:
    def rotateTheBox(self, box: List[List[str]]) -> List[List[str]]:
        m = len(box)
        n = len(box[0])
        result = []
        for i in range(m):
            k = -1
            for j in range(n-1, -1, -1):
                if box[i][j] == '.':
                    if k == -1:
                        k = j
                elif box[i][j] == '*':
                    k = -1
                else:
                    if k > -1:
                        box[i][j], box[i][k] = box[i][k], box[i][j]
                        k -= 1
        for i in range(n):
            row = []
            for j in range(m-1, -1, -1):
                row.append(box[j][i])
            result.append(row)
        return result