A big thank you to all who responded. There are too many to reply individually, but to summarise ...
Thomas Güttler gave a link to an example program, editMetadata.py which uses yes no dialogs and scaled images. I've not yet tried to learn from this, but looking at the code it seems to provide exactly what I am looking for. It uses the gtkMessageDialog class, which I hadn't come across (the tutorial doesn't seem to mention it?) Others recommended wxPython, PyQt and various derivatives. The trouble is there's too much choice! But my experience is that under Linux nothing ever works out of the box, and so I am reluctant to invite more grief by installing fresh packages until I am sure those already installed are not adequate. Easygui had some supporters. I had already come across this, and while I agree it is a delightfully simple tool to use, and ideal for i/o operations, it is not sufficiently flexible for my needs. One development is that my local public library has, to my surprise, managed to locate a copy of 'Python and Tkinter Programming' by J. Grayson. I've not read it yet, and an initial flick through doesn't look too promising but maybe I am mistaken.. I acknowledge that Tkinter is a bit dated, and may not have a native 'look and feel', but for me this would be outweighed by an accessible textbook. So currently the choice is between continuing with PyGtk, using the editMetadata.py code as a model, or Tkinter using Grayson's book. I'll try both and see which is more successful. Once again thank you to all who responded. -- http://mail.python.org/mailman/listinfo/python-list