numpy中數據的升維

這里給出一維和二維數組的實例，至於三維及更高維的就自行腦補了

一維：

import numpy as np     
a = np.array([1, 2, 3])
print(a.shape)     ----->(3,)

b = a[None]
print(b.shape)     ----->(1, 3)

c = a[:, None]
print(c.shape)     ----->(3, 1)

二維：

import numpy as np     
d = np.array([[1, 2, 3], [1, 2, 3]])
print(d.shape)       ----->(2, 3)

e = d[:, :, None]
print(e.shape)       ----->(2, 3, 1)

f = d[:, None, :]
print(f.shape)        ----->(2, 1, 3)

總結：None所在的位置就是需要升維的位置。