Is it possible to modify the numpy.random.choice function in order to make it return the index of the chosen element? Basically, I want to create a list and select elements randomly without replacement

import numpy as np
>>> a = [1,4,1,3,3,2,1,4]
>>> np.random.choice(a)
>>> 4
>>> a
>>> [1,4,1,3,3,2,1,4]

a.remove(np.random.choice(a)) will remove the first element of the list with that value it encounters (a[1] in the example above), which may not be the chosen element (eg, a[7]).

Here's one way to find out the index of a randomly selected element:

import random # plain random module, not numpy's
random.choice(list(enumerate(a)))[0]
=> 4      # just an example, index is 4

Or you could retrieve the element and the index in a single step:

random.choice(list(enumerate(a)))
=> (1, 4) # just an example, index is 1 and element is 4