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exceptions and message boxes

Catch the exception

Python spots when an exception is thrown, and you can write some code to
run when the exception occurs. This is called catching the exception. The code
that you run when there’s an error resulting in the thrown exception is called
an exception handler.

Bang!
def save_data():
fileD = open("deliveries.txt", "a")
fileD.write("Depot:\n")
fileD.write("%s\n" % depot.get())
OK, it says here I can
fileD.write("Description:\n")
recover by displaying
fileD.write("%s\n" % description.get()) an error message, then
fileD.write("Address:\n") restarting from this line
of code...
fileD.write("%s\n" % address.get("1.0", END))
depot.set("")
description.delete(0, END)
description.delete(0, END)
address.delete("1.0", END) Exception
You can CATCH handling
an exception. code.

A piece of code
Creating exception handlers can really make life easy for your users. Instead
of a flaky program that crashes or fails silently the first time something weird that runs when
happens, you can write programs that gracefully recover from errors. Exception
handlers tidy up when something goes wrong and can even let your user an exception is
know that something strange happened.

That’s what you need here: an exception handler that tells the user when thrown is called an
there’s a problem writing a delivery to the file.
exception handler.

How are exception handlers written in Python?

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