Rs.ReverseCurve(curve) output?

For me personally rs.ReverseCurve(curve) would be easier to use if it returned a curve that was reversed instead of changing the curve that you pass in.

It seems that most of the vector methods don’t affect the vector that you pass in but instead return a new vector.

Is there any rule as to when I can expect functions to change the value I pass in? Or is it just on a function to function basis.

Well, I guess this is just mimicking the command Flip (which does not make a copy), but I agree that it might be useful to have a second optional argument to make a copy or not (both in Python and VB).