worker thread catching exceptions and putting them in queue

[Paul Sijben]

Stargaming & Diez,

thanks very much!

Stargaming wrote:
> Paul Sijben schrieb:
>> All,
>>
>> in a worker thread setup that communicates via queues is it possible to
>> catch exceptions raised by the worker executed, put them in an object
>> and send them over the queue to another thread where the exception is
>> raised in that scope?
>>
>> considering that an exception is an object I feel it ought to be
>> possible, however I do not see how to go about it.
>>
>> does anyone have a pointer towards the solution?
>>
>> Paul
> 
> You're right, even exceptions are objects in Python. For further
> studies, read http://docs.python.org/lib/module-exceptions.html
> 
> You can catch an exception like this:
> try:
>   worker.do_some_work_that_may_raise_an_exception()
> except Exception, e:
>   # the first argument is the type of error you want to handle
>   # it is Exception here, the baseclass of all computation exceptions
>   # the second argument is the variable (name) where you want to save
>   # the specific exception raised to
>   # it's 'e' here, a common shortcut for exception
>   exception_handler.handle(e)
>   # notice that you can pass e around as you like
> 
> For further information on exceptions and how to handle them, read
> chapter 8 of the tutorial, especially starting from 8.3:
> http://docs.python.org/tut/node10.html#SECTION0010300000000000000000
> 
> P.S. I don't know if what I told still applies to Python 3.0 -- a lot of
> changes are upcoming related to exception raising and handling.