Blender - Import each FBXs stuff into respective collection with a null

"""Import every FBX in a directory into an individual collection.

Run this script from Blender 5.2's Scripting workspace.  Each FBX is imported
using the native FBX importer defaults, then its imported objects are moved to
a collection named after the FBX and parented to a ``<FBX name> Null`` empty.
"""

from pathlib import Path

import bpy


FBX_DIRECTORY = Path(r"K:\Videos\Weapons\Starship Troopers Guns\All FBXs")


def get_or_create_collection(name: str) -> bpy.types.Collection:
    """Return a scene-linked collection with *name*."""
    collection = bpy.data.collections.get(name)
    if collection is None:
        collection = bpy.data.collections.new(name)
        bpy.context.scene.collection.children.link(collection)
    return collection


def move_to_collection(obj: bpy.types.Object, collection: bpy.types.Collection) -> None:
    """Make *collection* the object's only collection."""
    for current_collection in tuple(obj.users_collection):
        current_collection.objects.unlink(obj)
    collection.objects.link(obj)


def import_fbx(fbx_path: Path) -> None:
    """Import one FBX and organize every object created by that import."""
    objects_before = set(bpy.data.objects)

    # Supplying only filepath deliberately uses Blender 5.2's native importer
    # default settings for every FBX.
    bpy.ops.wm.fbx_import(filepath=str(fbx_path))

    imported_objects = [obj for obj in bpy.data.objects if obj not in objects_before]
    if not imported_objects:
        print(f"No objects were imported from: {fbx_path}")
        return

    asset_name = fbx_path.stem
    collection = get_or_create_collection(asset_name)

    empty = bpy.data.objects.new(f"{asset_name} Null", None)
    empty.empty_display_type = 'PLAIN_AXES'
    collection.objects.link(empty)

    for obj in imported_objects:
        move_to_collection(obj, collection)
        # The empty is at the world origin, so this preserves imported transforms
        # while making every imported object a child of the asset empty.
        obj.parent = empty
        obj.matrix_parent_inverse = empty.matrix_world.inverted()

    print(f"Imported {fbx_path.name}: {len(imported_objects)} objects -> {collection.name}")


def main() -> None:
    if not FBX_DIRECTORY.is_dir():
        raise FileNotFoundError(f"FBX directory does not exist: {FBX_DIRECTORY}")

    fbx_files = sorted(
        (path for path in FBX_DIRECTORY.iterdir() if path.is_file() and path.suffix.lower() == ".fbx"),
        key=lambda path: path.name.casefold(),
    )
    if not fbx_files:
        print(f"No FBX files found in: {FBX_DIRECTORY}")
        return

    for fbx_path in fbx_files:
        import_fbx(fbx_path)

    print(f"Finished importing {len(fbx_files)} FBX file(s).")


if __name__ == "__main__":
    main()