﻿ NumPy: Create an array (a) of shape 3, 4, 8 - w3resource # NumPy: Create an array (a) of shape 3, 4, 8

## NumPy: Array Object Exercise-162 with Solution

Create an array (a) of shape 3, 4, 8 (K=3, J=4, I=8). tidx is an array of the same length as a.shape, i.e. contains J = 4 elements where each index denotes which element of K should be chosen.
Write a NumPy program to select from the first axis (K) by the indices tidx to get an array of shape (J=4, I=8) back.

Sample Solution:

Python Code:

``````import numpy as np
a = np.random.randint(0, 10, (3, 4, 8))
print("Original array and shape:")
print(a)
print(a.shape)
print("--------------------------------")
tidx = np.random.randint(0, 3, 4)
print("tidex: ",tidx)
print("Result:")
print(a[tidx, np.arange(len(tidx)),:])
```
```

Sample Output:

```Original array and shape:
[[[3 2 2 7 7 7 0 3]
[5 8 4 2 9 9 3 9]
[6 8 2 8 5 7 8 7]
[5 2 4 0 4 9 2 5]]

[[4 3 1 8 2 5 2 0]
[9 1 5 8 8 5 6 5]
[3 2 2 0 1 5 6 1]
[5 1 9 4 2 6 9 2]]

[[4 6 6 3 8 6 8 8]
[3 9 2 6 3 3 1 0]
[5 4 0 6 0 2 7 8]
[6 3 1 8 8 1 5 7]]]
(3, 4, 8)
--------------------------------
tidex:  [0 2 2 2]
Result:
[[3 2 2 7 7 7 0 3]
[3 9 2 6 3 3 1 0]
[5 4 0 6 0 2 7 8]
[6 3 1 8 8 1 5 7]]
```

Python Code Editor:

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Set comprehension:

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>>> m
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```