Python - How to scale selected values in array?

I'm trying to normalize a certain range of number in a data set. For context, I'm trying to fit the blue jagged line on the left part of the graph (before 550 nm) so that it "fits" the green line. Everything after that point is perfectly fine. Is their a way to where I can just select a certain range of my array and scale it while leaving the rest of the data un-normalized?