Get a subarray from a numpy array based on index

Question

I have a numpy array vector, and I want to get a subset based on the indexes:

import numpy as np
input=np.array([1,2,3,4,5,6,7,8,9,10])
index=np.array([0,1,0,0,0,0,1,0,0,1])

what is a pythonic way to get out output=[2,7,10]?

Fred Foo · Accepted Answer · 2013-04-25 19:00:22Z

8

output = input[index.astype(np.bool)]

or

output = input[np.where(index)[0]]

answered Apr 25, 2013 at 19:00

Fred Foo

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1 Comment

input[index == 1] might also be worth mentioning.