How to rearrange array based upon index array

Question

I\'m looking for a one line solution that would help me do the following.

Suppose I have

array = np.array([10, 20, 30, 40, 50])

I\

Answer 1

For those who have the same confusion, I am actually looking for a slightly different version of "rearrange array based upon index". In my situation, the index array is indexing the target array instead of the source array. In other words, I am try to rearrange an array based on its position in the new array.

In this case, simply apply an argsort before indexing. E.g.

>>> arr = np.array([10, 20, 30, 40, 50])
>>> idx = [1, 0, 3, 4, 2]
>>> arr[np.argsort(idx)]
array([20, 10, 50, 30, 40])

Note the difference between this result and the desired result by op.

One can verify back and forth

>>> arr[np.argsort(idx)][idx] == arr
array([ True,  True,  True,  True,  True])
>>> arr[idx][np.argsort(idx)] == arr
array([ True,  True,  True,  True,  True])