﻿ NumPy: Calculate the sum of all columns of a 2D NumPy array - w3resource # NumPy: Calculate the sum of all columns of a 2D NumPy array

## NumPy: Array Object Exercise-152 with Solution

Write a NumPy program to calculate the sum of all columns of a 2D NumPy array.

Sample Solution:

Python Code:

``````import numpy as np
num = np.arange(36)
arr1 = np.reshape(num, [4, 9])
print("Original array:")
print(arr1)
result  = arr1.sum(axis=0)
print("\nSum of all columns:")
print(result)
```
```

Sample Output:

```Original array:
[[ 0  1  2  3  4  5  6  7  8]
[ 9 10 11 12 13 14 15 16 17]
[18 19 20 21 22 23 24 25 26]
[27 28 29 30 31 32 33 34 35]]

Sum of all columns:
[54 58 62 66 70 74 78 82 86]
```

Pictorial Presentation: Python Code Editor:

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## Python: Tips of the Day

List comprehension:

```>>> m = [x ** 2 for x in range(5)]
>>> m
[0, 1, 4, 9, 16]
```