def is_scalar(obj): try: obj+1 except TypeError: return False
>> else: return True
> This seems to have broken axes.legend(), which for some
> reason calls flatten(handles), where handles contains
> instances of classes like lines.Line2D, which fail the new
> is_scalar test. I don't see why the list should need
> flattening, except if the user passes in a non-flat list.
Oh, I see. Apparently is_scalar was a badly named function. I'm
going to temporarily revert to the old behavior and then do a cleanup
and rename later -- after testing this time 
JDH