Blender script for changing the internal order of objects

change_objects_internal_order.py

# WARNING: this may make blender forget some stuff,
# it at least forgets the hide/shown status of every object

# this is useful when export order is an issue

# MODIFY THIS
# move element at index 3 by -2, so it ends up at index 1
# move element at index 7 by 3, so it ends up at index 10
moves = [[3,-2],[7,3]]

# OR order objects by name
# get base list with [o.name for o in bpy.context.scene.objects.values()]
# objects not in this list will be left unchanged, objects here will be put after
# uncomment to use instead of moves (remove # on next line)
#orderedNames = ['Cube', 'Icosphere']

import bpy

# context
scene = bpy.context.scene

if orderedNames is None:
    objects = [o for o in scene.objects]
    # compute the moves
    for move in moves:
        index = move[0]
        moveBy = move[1]
        e = objects[index]
        del objects[index]
        objects.insert(index+moveBy, e)
else:
    objects = [scene.objects[n] for n in orderedNames]

# for each name, put the corresponding object at the end of the object list
# could be greatly improved if blender had a simple way to get an object's parent collection?
for object in objects:
    # find the object's parent collection (breadth-first search)
    toVisit = [scene.collection]
    objCollection = None
    while len(toVisit) > 0:
        c = toVisit[0]
        del toVisit[0]
        toVisit += c.children
        if object in c.objects.values():
            objCollection = c
            break
    # move object to end of list
    if objCollection is None:
        print('/!\ Couldnt find parent collection of ' + object.name) # hopefully unreachable
    else:
        objCollection.objects.unlink(object)
        objCollection.objects.link(object)