提取列
data = np.array([[1, 2, 3, 4],
[5, 6, 7, 8],
[9, 10, 11, 12]])
x = data[:, [1, 3]] # 取第2,4列
print(x)
>>> [[ 2 4]
[ 6 8]
[10 12]]
提取行
data = np.array([[1, 2, 3, 4],
[5, 6, 7, 8],
[9, 10, 11, 12]])
x = data[[0, 2]] # 取第1,3行 也可以写成 data[[0, 2], :]
print(x)
>>> [[ 1 2 3 4]
[ 9 10 11 12]]