> From: "Brian van den Broek" <[EMAIL PROTECTED]> > To: "Diana Hawksworth" <[EMAIL PROTECTED]> > Cc: <tutor@python.org> > Sent: Saturday, April 16, 2005 3:14 PM > Subject: Re: [Tutor] exceptions > > Diana Hawksworth said unto the world upon 2005-04-15 22:25: > > > Hello list, > > > > > > I have been trying to trap a string entry by raising an exception. The > code follows - but the exception is never raised. What am I doing wrong? > > > > > > TIA Diana > > > > > > try: > > > > > > self.guess = int(self.num_ent.get()) > > > > > > self.num_ent.delete(0,END) > > > self.num_ent.focus_set() > > > > > > > > - Ignored: > > > if self.guess < self.number: > > > message = str(self.guess) + " is too low. You need to > guess higher" > > > > > > if self.guess > self.number: > > > message = str(self.guess) + " is too high. You need to > guess lower" > > > > > > if self.guess == self.number: > > > message = str(self.guess) + " is the correct number!" > > > self.message_txt.config(state = NORMAL) > > > self.message_txt.config(state = DISABLED) > > > > > > self.message_txt.config(state = NORMAL) > > > self.message_txt.delete(0.0, END) > > > self.message_txt.insert(0.0, message) > > > self.message_txt.config(state = DISABLED) > > > > > > > > > except(ValueError): > > > message = str(self.guess) + " is not a number. Please try > again!" > > > > > > > Hi Dianna, > > > > What are you expecting to raise the ValueError? It looks to me like it > > must be the line: > > > > self.guess = int(self.num_ent.get()) > > > > But, if that is so, then the assignment to message in your except > > clause won't work, as self.guess won't have been assigned. > > > > I'm no expert, so I may be missing something, but I wouldn't be > > surprised if your num_ent.get() has details that are pertinent. What > > does that method return? > > > > And, while I'm writing, I'd suggest rewriting your lines like: > > > > message = str(self.guess) + " is the correct number!" > > > > in this form instead: > > > > message = "%s is the correct number!" %self.guess > > > > The almost irrelevant benefit is that it is faster. The big plus is > > string formatting is so handy, that I think it helps a lot to get used > > to using it in most cases, even those that are easy to handle with > > string concatenation as you have done. > > > > Best, > > > > Brian vdB > > > > > Thanks for your reply Brian. The num_ent.get() method returns a number. > Actually, it is an Entry box that returns a string, that I then convert to > an integer. What I would like to do, is, if a user enters a string, to have > the program return an exception. At the moment it just blithely carries on > as if the string that was entered was in fact an integer, and compares that > entered string to a random number! > > Thanks for the hint on string formatting! I had forgotten about that! Been doing > this for a month only!!! > > Thanks again. Diana > > > > - Done. > >
_______________________________________________ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
