``` import threading data_list = [] def task(arg): data_list.append(arg) print(data_list) def run(): for i in range(10): p = threading.Thread(target=task, args=(i,)) p.start() if name == 'main': run() ''' [0] [0, 1] [0, 1, 2] [0, 1, 2, 3] [0, 1, 2, 3