Proper way to handle errors in a module

[Ethan Furman]

Andrew Berg wrote:
> On 2011.05.12 02:25 PM, MRAB wrote:
>> You can raise an exception wherever you like! :-)
> If I raise an exception that isn't a built-in exception, I get something
> like "NameError: name 'HelloError' is not defined". I don't know how to
> define the exception.

class HelloError(Exception):
     "custom exception"

and that's all you need.  You can override __init__ to add your own 
attributes, etc, if you need to.

~Ethan~