"Dick Moores" <[EMAIL PROTECTED]> wrote > Thanks. You've clarified it for me completely. > > Your second way seems to make more sense. > And instead of raising the error, why not just print it:
Because that would make the class much less reusable. It would be limited to applications using stdout. A GUI banking program would be unable to use the BankAccount class. But by raising an exception the user gets to decide what to do, either pop up a dialog, print a message or send an email to the banks client. Its a primary design goal for reuse to de-couple business logic - like the bank account - from the user interface. There is a bit more discussion around this in my Case Study topic where I convert it from command line to GUI and again in my InterProcess Comms topic where I turn the AddressBook into a client-server app. HTH, -- Alan Gauld Author of the Learn to Program web site http://www.freenetpages.co.uk/hp/alan.gauld _______________________________________________ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
