Matplotlib Widgets - Drop down boxes

Hi all,

I have been looking at the Matplotlib widget examples particularly the
Slider one and then looking at the widgets available in
matplotlib.widgets. I noticed that there are no list or drop down
widgets available? Is this something that is available elsewhere in
Matplotlib or something that needs to be added? It would be extremely
convenient to be able to use drop down boxes in plots to control the
data going into the plot.

Does anyone have any thoughts or suggestions. Is this something
others are interested in or already working on? Is there a technical
difficulty that drop downs present that has caused people to be
hesitate to add them?