Setup multi scene rendering

multi_scene_setup.py

# made in answer to http://blender.stackexchange.com/q/74086/935

import bpy

master_render_scene_name = 'Multi_render'
base_path = '//renders/'

if master_render_scene_name not in bpy.data.scenes:
    bpy.data.scenes.new(name=master_render_scene_name)

masterScene = bpy.data.scenes[master_render_scene_name]
masterScene.use_nodes = True
masterNodeTree = masterScene.node_tree

for n in masterNodeTree.nodes:
    masterNodeTree.nodes.remove(n)

fileNode = masterNodeTree.nodes.new('CompositorNodeOutputFile')
fileNode.base_path = base_path
fileNode.format.file_format = 'PNG'
fileNode.format.color_mode = 'RGBA'
for s in fileNode.file_slots:
    fileNode.file_slots.remove(fileNode.inputs[0])

nspacing = 40
nx = (len(bpy.data.scenes)*nspacing)/2
for scn in bpy.data.scenes:
    if scn.name == master_render_scene_name:
        continue
    sp = scn.render.filepath.replace(base_path,'')
    fs = fileNode.file_slots.new(sp)
    rl = masterNodeTree.nodes.new('CompositorNodeRLayers')
    rl.scene = scn
    rl.hide = True
    rl.location.x = -300
    rl.location.y = nx
    nx -= nspacing
    masterNodeTree.links.new(rl.outputs['Image'], fs)