[:,None]
None表示该维不进行切片,而是将该维整体作为数组元素处理。
所以,[:,None]的效果就是将二维数组按每行分割,最后形成一个三维数组
features.head()
temp = np.array(features)
print(temp[:,None])
[[[ 0. 0. -1.33460919 ..., 0. 0. 1. ]]
[[ 0. 0. -1.43847501 ..., 0. 0. 1. ]]
[[ 0. 0. -1.43847501 ..., 0. 0. 1. ]]
...,
[[ 1. 0. 0.11951233 ..., 0. 0. 0. ]]
[[ 1. 0. -0.19208513 ..., 0. 0. 0. ]]
[[ 1. 0. -0.19208513 ..., 0. 0. 0. ]]]
temp1 = temp[:,None]
print(temp1.shape)
print(temp1.ndim)
(16875, 1, 56)
3