python move first level child files from directories to root of script, not recursive

unpack.py

import os
import shutil

root = os.path.split(__file__)[0]

for dirpath, dirname, filenames in os.walk(root):
    if filenames:
        for file in filenames:
            old_path = os.path.join(dirpath, file)
            new_path = os.path.join(root, file)
            shutil.move(old_path, new_path)