Python 矩阵、行和列

Question

我有一些问题矩阵：

b=   [[-2.5,  0.5],        #b is random matrix
     [-1.5, -0.5],
     [-0.5,  0.5]]

如何从 b 得到：

b=[[[-2.5], [0.5]], [[-1.5], [-0.5]], [[-0.5], [0.5]]]

非常感谢

Answer 1

>>> b=   [[-2.5,  0.5],        #b is random matrix
     [-1.5, -0.5],
     [-0.5,  0.5]]
>>> [[[val] for val in row] for row in b]
[[[-2.5], [0.5]], [[-1.5], [-0.5]], [[-0.5], [0.5]]]

---

说明：考虑一个列表：

>>> oned = [1, 2, 3]

您可以使用列表理解重新创建它：

>>> [val for val in oned] 
[1, 2, 3]

然后将每个元素包装在自己的列表中：

>>> [[val] for val in oned]
[[1], [2], [3]]

将其扩展到二维。

Answer 2

克劳迪乌的答案可能更简单，但这里有一个替代解决方案递归地遍历任意深度的列表的列表。

>>> listify = lambda x: map(listify, x) if isinstance(x, list) else [x]
>>> listify(b)
[[[-2.5], [0.5]], [[-1.5], [-0.5]], [[-0.5], [0.5]]]