How to sum elements of same position in n dimensional array

[Felipe]

Hi, guys,

I have a numpy array of (2,100,2) dimensions, that I want to sum elements of the same position. In order to clarify my doubts, I wrote the example below where I substituted the numbers by letters with dimensions (2,2,2): 

[[[a b]
  [c d]]
 [[a b]
  [c d]]]

So, I look for a way to sum a+a, b+b, c+c, d+d, and obtain an array with dimensions (2,2,1). Here's the desired output:

[[a+a  b+b]
 [c+c  d+d]]

I'd like something that I can extrapolate to cases with dimensions (2,100,X), where X can be numbers from 2 to 10.
Thanks !!!