Blender Script to Extract Collection children with type of Collection instances into new Collection and categorized as individual object

blender_extract_collection_inside_collection.py

import bpy

# Name of the main collection
main_collection_name = "MainCollection"
new_collection_name = "NewCollection"

# Get the main collection by name
main_collection = bpy.data.collections.get(main_collection_name)

if main_collection:
    # Create a new collection for the extracted objects
    new_collection = bpy.data.collections.new(new_collection_name)
    bpy.context.scene.collection.children.link(new_collection)

    # Iterate through all objects in the main collection
    for obj in main_collection.objects:
        # Check if the object is an instance (type 'COLLECTION')
        if obj.instance_type == 'COLLECTION':
            # Iterate through linked objects in the instance
            for linked_obj in obj.instance_collection.objects:
                # Duplicate the object and link it to the new collection
                new_obj = linked_obj.copy()
            
#                new_obj.matrix_world = obj.matrix_world.copy()
                new_obj.location = obj.location.copy() + linked_obj.location.copy()
                
                new_obj.scale = obj.scale.copy() * new_obj.scale.copy()
                                
                euler_new = linked_obj.rotation_euler.copy()
                
                euler_new.x = linked_obj.rotation_euler.copy().x + obj.rotation_euler.copy().x
                euler_new.y = linked_obj.rotation_euler.copy().y + obj.rotation_euler.copy().y
                euler_new.z = linked_obj.rotation_euler.copy().z + obj.rotation_euler.copy().z
                
                new_obj.rotation_euler = euler_new.copy()
                

                new_collection.objects.link(new_obj)

# Clear the selection to avoid selecting objects in the new collection
bpy.ops.object.select_all(action='DESELECT')