switch blending modes in Roto and RotoPaint nodes in Nuke

blending_mode_switcher.py

def blending_mode_switcher():
    MODES = ['color-burn', 'color-dodge', 'difference', 'exclusion', 'from', 'hard-light', 'max', 'min', 'minus', 'multiply', 'over', 'overlay', 'plus', 'screen', 'soft-light'] # OR ['max', 'over']
    SUPPORTED_NODES = ['Roto', "RotoPaint"]
    nodes = nuke.allNodes(recurseGroups = True)
    
    active_nodes  = [node for node in nodes if (node.shown() and node.Class() in SUPPORTED_NODES)]
    for found in active_nodes:
        try:
            current_mode = found['toolbar_blending_mode'].value()
        except:
            continue
        
        try:
            index = MODES.index(current_mode)
        except:
            index = -1
        
        index = (index+1)%len(MODES)  
        found['toolbar_blending_mode'].setValue(MODES[index]) 


#### ADD TO STANDART MENU

nuke.menu('Nuke').addCommand("Edit/Node/Switch Blending Mode", "blending_mode_switcher()", "shift+Q" )