Playing with NumPy

Question

https://code.sololearn.com/cfEGBBQKlJb4/?ref=app

What is a[None]?
Why it is [[1 2 3 4 5]]?

Code:
import numpy as np
a = np.array(range(6))
print(a)
print(a[None])

Output:
[1 2 3 4 5]
[[1 2 3 4 5]]

Answer 1

https://stackoverflow.com/questions/1408311/numpy-array-slice-using-none

Answer 2

It's so simple! a[None] is a[None, :, :]!
But it seemed really strange and unclear last night, when I was sleeppy ;)