On Tue, 15 Nov 2005 17:03:24 +0100 (MET)
[EMAIL PROTECTED] wrote:
>
> I would like to ask another question. I don't understand the exception
> mechanism
> of Python when running a Tkinter app. If an exception happens (it does
> happen quite often
> at the moment..), a traceback is written to the console while the Tk window
> remains open
> and the application is still running. This is not what I expected -- I
> expected the application
> would end. Why is that?
>
> Is there a way to create an error handler for uncaught exceptions in Tkinter
> apps?
> In other words, can I change the behaviour from writing a traceback to the
> console to
> something else? Can I, for example, show a message box instead?
>
If you only want to see the traceback in your gui, I recommend using Pmw.
Pmw pops up a Text window that shows the complete traceback, it doesn't catch
the exception though.
> Here is a small example:
>
> --- snip ---
> import Tix
>
> def raise_exception():
> print 1/0
>
> if __name__ == '__main__':
> root = Tix.Tk()
> root.title("Exception demo")
>
> Tix.Button(root, text = "Don't press", command = raise_exception).pack()
>
> try:
> root.mainloop()
> except:
> print "An error has occured."
> --- snip ---
>
> The except part gets never executed.
>
That's because the error isn't in the mainloop() method.
Probably you meant something like
def raise_exception():
try:
print 1 / 0
except ZeroDivisionError:
print "An error has occured."
# or with a message box:
# tkMessageBox.showerror(message='ZeroDivisionError')
?
Thank god python is nice enough to raise the error where it actually happens;
imagine your example would work, you would never know *where* the error happened
nor could you create adequate handlers for different exceptions in different
situations.
I hope this helps
Michael
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