初始化 3D 数组

你可以进一步向下并添加第三层阵列。规则不会改变：

my_array = [
  [
    [1, 1, 2, 3, 5, 8, 13],
    [1, 4, 9, 16, 25, 36, 49, 64, 81],
    [2, 3, 5, 7, 11, 13, 17]
  ],
  [
    ['a', 'b', 'c', 'd', 'e'],
    ['z', 'y', 'x', 'w', 'v']
  ],
  [
    []
  ]
]