Many thanks for the repsonse - much appreciated. And sorry - yes I was probably compounding two separate issues here - the GUI one and the variable scope one. Maybe the wxPython list would be the best place to ask more about the GUI side of things.
Then actually I can simplify my remaining question quite a lot - I know you've partly answered this already but let me just rephrase this: It must be commonplace to first use a variable or object within one function in a module and then want to use it again - perhaps still with the same value as in the first function - in a second function. So what's the recommended Python way round this? If I was using .Net then I'd be declaring the variables/objects explicitly and could set their scope according to how/where they were declared. But if the Python way is not to declare vars before use then this must create some problems for cross-function use. So it is best to declare such vars at the module level (ie outside of a function) and set eg to Null/None or to assign them with a keyword such as global or static (assuming that concept applies in Python) at first use inside a function or what? JGD -- http://mail.python.org/mailman/listinfo/python-list