Adding value to array

Question

I want to add values from one array to another array after making some calculation, here I did it using for loop but I want efficient way doing so. Please help me.. thanx

from numpy import *
arr = array([1,2,3,4,5])
arr1 = []
for i in arr:
 arr1.append(i+5)
 
print(arr1)
nArray = array(arr1)
print(nArray)

Output :

[6, 7, 8, 9, 10]

[ 6 7 8 9 10]

• swag2198: Simply do arr1 = arr + 5. Numpy broadcasting will take care of the rest.
• Rohit: Thanx Gilad Green

Answer 1

You should have just done:

nArray = arr + 5

Answer 2

For a builtin Python list, you can use a list comprehension:

arr1 = [x + 5 for x in arr]

Since you are using a numpy array however, you can just add 5 to the array with:

arr1 = arr + 5

• Mykola Zotko: Remove the first part. It's correct but not efficient for numpy.
• Rohit: Thanx Thomas Saint