moving marker line under mouse


how could I realize a moving marker line under the mouse pointer?

I know about event handling

and would use ‘ axes_enter_event’ to react on, then draw a line

axvline(x=event.xdata, linewidth=1, color='r')

but how can I delete the line again without deleting my whole plot
I have on that axes/subplot?

Also I didn't see any "mouse move" event that would recognize a
change in cursor position? Or is that what is meant with

If that is so, it comes down to know how to delete a vertical line on
a mouse_notify_event. Is there a way to get a (named) list of plots
on a particular subplot?

In a different context I tried to keep my on list in a python
self.axes list, but that was very tedious and I didn't finish
it to work properly.