New characteristic to cumsum
Hi, I would like to know if is possible to add to the cumsum method the option to make an operation (multiplication of a constant for example or a lambda function) while it is making every sum to get something like this: https://stackoverflow.com/questions/34182755/cumulative-addition-multiplication-in-numpy, I know this could look a little unnecesarry but this kind of cumulative sum appears in a lot of formulas of economic indexs and I think there are other cases where this can be useful. The reason of this request is that when the data is very big use a normal python loop is not a nice option due to the time it take, or even using the solution of the link is not a good idea due to the precision of the floats number.
