If we open a file with IDLE, then start a new IDLE windows from it, we can import the module that is the child module of idlelib, example ‘help’, ‘pyshell’ and so on. I think that now there is still many schools use IDLE to teach python to prevent students from downloading malicious plug-ins from the IDE, if students import those module, it will result in misleading.
I thought that it is the problem of “sys.path” first, so I tried to remove the module “idlelib” 's path in many codes in the module “idlelib”. However, it seems to be useless.