[Tkinter-discuss] update_idletasks problem

[Russell Blau]

I have an application with a button that calls a method that retrieves a
page from an external wiki, so it can take a while.  I want to use an
hourglass/watch cursor to indicate to the user that the page is loading.
All the documentation suggests that the way to do this is as follows:

def my_slow_method(self):
    self['cursor'] = 'watch'
    self.update_idletasks()
    retrieve_page_from_wiki()     # placeholder for my slow retrieve
function
    self['cursor'] = ''

where "self" is my Tkinter application, defined as a subclass of
Tkinter.Frame.

The only problem is, this doesn't work.  The cursor never changes to the
hourglass!  If I comment out the last line, it does change to an hourglass
*after* retrieving the page from the wiki, but obviously that's not what I
want to do.  What's wrong?

I'm running Python 2.4 on Windows XP.