如何以交替顺序遍历2D数组

def alternate_traverse_2d_array(arr):
    rows = len(arr)
    cols = len(arr[0])
    row = 0
    col = 0
    direction = 1  # 1: left to right, -1: top to bottom

    while row < rows and col < cols:
        if direction == 1:
            for i in range(col, cols):
                print(arr[row][i])  # 输出或处理元素
            row += 1
            direction = -1
        else:
            for i in range(row, rows):
                print(arr[i][col])  # 输出或处理元素
            col += 1
            direction = 1

# 示例用法
array = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
alternate_traverse_2d_array(array)