drag and drop graphics in tkinter?

[Sean McIlroy]

Eric Brunel <eric_brunel at despammed.com> wrote in message news:<41a2fb94$0$8155$8fcfb975 at news.wanadoo.fr>...

> I'm not quite sure I understand your question: drag and drop between what and 
> what?

I'm looking for a way to use drag-and-dropping to pick up a graphic
and move it from one place to another. For example, I thought I could
get my feet wet by writing a script to represent small graphs (in the
nodes-and-vertices sense) as collections of dots and lines onscreen.
Moving the the dots around (while maintaining line-indicated
connections between dots) could furnish a graphical way of
investigating questions like planarity and isomorphism.