[Tutor] Guidance on using custom exceptions please

[David Aldrich]

> If you don't want to let the original timeout error bubble up you can create
> your own little hierarchy of exceptions:
> 
> class ResponseError(Exception):
>     pass
> 
> class TimeoutError(ResponseError):
>     pass
> 
> class BadDataError(ResponseError):
>     pass
> 
> Then the baseclass of ResponseError doesn't matter much as client code that
> wants to catch every expected error can catch ResponseError. You can later
> add subclasses as needed without breaking this catch-all client.

Thanks for all the answers to my question, they were all helpful.

I have one more question, which regards style.  Suppose my 'send' method is in its own module: TxControl, along with the custom exceptions:

TxControl.py:

class MessageTimeoutError(Exception): pass
class UndefinedMessageTypeError(Exception): pass

def send(msg)
     etc.

Then it seems that an importer of that module must include the module name when referencing the exceptions:

import TxControl

try:
    send(msg)
except (TxControl.MessageTimeoutError, TxControl.UndefinedMessageTypeError) as err:
    # Exception processing

Including 'TxControl' seems a bit tedious, and is even worse if TxControl imports exceptions from yet another module and allows them to pass up the stack.

How would you handle this situation stylistically?

David