Selecting all Empties without Children

Question

I have a large structured model with thousands of parts. During CAD export (to fbx), the file was simplified and many small parts (such as screws and washers) were removed. However, in Blender I now have many 'empties' without any children below it. I'd like to select all the empties that have no children, so that I can delete them all.

Answer 1

Achim's script to select Empties without children can be optimized and simplified:

import bpy

# select empties
bpy.ops.object.select_by_type(extend=False, type='EMPTY')
empties = bpy.context.selected_objects

# remove elements with children from selection
for obj in empties:
    if len(obj.children) > 0:
        obj.select_set(False)

print('{} empties were selected'.format(len(bpy.context.selected_objects)))

To delete all Empties without children automatically you can modify this script like so

import bpy

iteration = 1
print('Iteration {}'.format(iteration))
iteration = iteration + 1

# select empties
bpy.ops.object.select_by_type(extend=False, type='EMPTY')
empties = bpy.context.selected_objects

print('Total empties: {}'.format(len(empties)))

while len(empties) > 0:

    # deselect everyting
    bpy.ops.object.select_all(action='DESELECT')

    parents = []
    # select childless nodes and collect its parents to check in next iteration
    for obj in empties:
        if len(obj.children) == 0:
            obj.select_set(True)
            if obj.parent is not None:
                parents.append(obj.parent)

    count = len(bpy.context.selected_objects)
    if count == 0:
            break

    print('{} empties were selected'.format(count))
    bpy.ops.object.delete(use_global=True, confirm=False)
    
    empties = parents
    print('Iteration {}'.format(iteration))
    iteration = iteration + 1

print('Done')

The key trick here is that script checks deleted object parent if it became childless and iterates process untill no Empties without children left.