Given that i have a 2d array and i want to reshape it to 1d with one value per row

问题

This is my array

arr = np.array([[0, 1],
[3, 4],
[6, 7]])

flat_arr = np.reshape(arr, -1)

am getting the following result:

[0 1 2 3 4 5 6 7 8]

my desired result is :

[0]
[1]
[3]
[4]
[5]...

回答1:

There are several ways to do it:

flat_arr[:, None]
flat_arr[:, np.newaxis]
np.expand_dims(flat_arr, axis=1)

Additionally, you could just reshape it like so:

arr.reshape(-1, 1)

回答2:

You can use this new shape:

import numpy as np

arr = np.array([[0, 1], [3, 4], [6, 7]])

flat_arr = np.reshape(arr, (arr.shape[0] * arr.shape[1], 1))

print(flat_arr)

Output:

[[0]
 [1]
 [3]
 [4]
 [6]
 [7]]

Also, as @MarkMeyer has added, you could use:

flat_arr = np.reshape(arr, (-1, 1))

来源：https://stackoverflow.com/questions/64454473/given-that-i-have-a-2d-array-and-i-want-to-reshape-it-to-1d-with-one-value-per-r