How to use the bottle.static_file function in bottle

def description():
            filename = kwargs.get('corpus_desc')
            if not filename:
                response.status = 404
                return "File not found"
            filename = get_static_resource_path(filename)
            root, filename = os.path.split(filename)
            return static_file(filename, root=root)

def retrieveSkeleton(bodyId):
    return static_file(str(bodyId) + '.swc',
                       root='/Users/zhaot/Work/neutube/neurolabi/data/flyem/TEM/data_release/bundle1/swc')

@route('/')
def server_static(path):
    response.headers['Expires'] = time.strftime("%a, %d %b %Y %H:%M:%S GMT",
                                                time.gmtime(time.time() + 60 * 60 * 24 * 7))
    response.headers['Cache-control'] = "public"
    resp = static_file(path, root=join(PROJECT_DIR, app_path))
    # Also serve from .tmp folder in dev mode
    if resp.status_code == 404 and app_path == "app":
        return static_file(path, root=join(PROJECT_DIR, '.tmp'))

    return resp

def server_static(filepath):
    """Handler for static files, used with the development server."""
    root_folder = os.path.abspath(os.path.dirname(__file__))
    return bottle.static_file(filepath, root=os.path.join(root_folder, 'static'))

@route('/:username/xmls/:id')
def xmls(username, id, db):
    doc = db.getDocument(id)
    return static_file('%s.xml' % doc.id, root=config.XMLS_DIR)

@route('/')
def root():
    return static_file('index.html', root='./static')

def index():
  return static_file('index.html',root=here())

def send_file(filename):
    return static_file(filename, root='../redweb/static')

def server_static(filepath):
    """Handler for static files, used with the development server."""
    root_folder = os.path.abspath(os.path.dirname(__file__))
    return bottle.static_file(filepath, root=os.path.join(root_folder, 'static'))

def img(staticFiles) :

    return static_file(staticFiles , root="/home/pi/Desktop/SMARTHOME/html/Application/fonts")