I find this little code super useful. It allows you to flop all the nodes you have selected; pretty much reverse them in X. I honestly don't know who wrote it because a coworker sent it my way when I started learning Python. I have this code set to the hotkey ctrl+alt+f.
Expand Flop Nodes
import nuke def flopNodes(): nodes = nuke.selectedNodes() maxX = max( [ n.xpos()+n.screenWidth()/2 for n in nodes ] ) minX = min( [ n.xpos()+n.screenWidth()/2 for n in nodes ] ) centreX = (maxX - minX)/2 + minX for n in nodes : n.setXpos( (centreX + (centreX - (n.xpos() + n.screenWidth()/2 )))- n.screenWidth()/2)