[Twisted-Python] Handling errors when using deferToThread

[Andrew Bennetts]

On Fri, Oct 28, 2005 at 10:35:08AM -0400, Pedro Sanchez wrote:
[...]
> This works well as long as doLongCalculation() doesn't fail for
> any reason. But if it does, how can it trigger an errBack?

Just raise an exception.

> I want to do something like this:
> 
> from twisted.internet import threads
> def doLongCalculation():
>     try:
>        # .... do long calculation here ...
>     except:
>        < what can I return here to tell that
>          the calculation failed? >
>     return 3

The literal answer here is a bare raise statement.  But better would be to
not use the try-except at all.

Try inserting something like "1/0" into doLongCalculation and see what
happens.

-Andrew.