How to get elements for non-contiguous indices in a numpy array?

Question

Suppose I have a numpy array:

arr = np.array([1,2,3,4,4,5,3,2,10])

and an indices array:

indices = np.array([0,1,4,6])

I could write a simple function that does the job, but I was wondering if numpy has a built-function like np.get(arr, indices) which returns, in this case, np.array([1,2,4,3] .

Answer 1

This is called Advanced Indexing :

triggered when the selection object is a non-tuple sequence object, an ndarray (of data type integer or bool), or a tuple with at least one sequence object or ndarray (of data type integer or bool). There are two types of advanced indexing: integer and Boolean.

Advanced indexing always returns a copy of the data (contrast with basic slicing that returns a view).

Your situation is integer advanced indexing, where you pass an array of indexes to be retrieved. As sascha noted in comments, this will create a copy of the data, so the new array will exist independently from the original one (ie, writing to it will not modify the original array).