When provided object is not from a file, like input in interactive shell, `inspect` internals will check for it in `linecache`, which official Python shell and IDLE won't put interactive shell input into, yet. This can be simply solved.

Whether interactive shell input can be put into `linecache` may be a problem, but it'll make life easier, as interactive shell saves time from edit-save-run 'loop'.

btw, I changed the title, since I don't think, what original author thought need to be documented, is absolutely right.