[Twisted-Python] Re: Making DeferredList look like Deferred

Lenny G Arbage alengarbage at yahoo.com
Fri Feb 3 18:55:34 EST 2006

Jean-Paul Calderone exarkun at divmod.com
Fri Feb 3 14:08:54 MST 2006 wrote:
> DeferredList has *either* callback *or* errback
> called on it, just like any Deferred.  If you just
> give it a list of Deferreds, it will always have its
> callback method invoked and never have its errback
> method invoked, regardless of whether any of the
> Deferreds it was constructed with fail.  However, if
> you pass a true value for fireOnOneErrback when
> constructing your DeferredList, any Deferred which
> errbacks will cause the DeferredList to errback; in
> this case it will never callback.
> Does that help?

  That definitely helps, but I'm wondering if this
behavior was implemented between 1.3 and 2.0?  I can
provide an example where both the DeferredList's
errback and callback are called on 1.3 when any one of
the DeferredList's Deferreds err -- without setting
fireOnErrback.  I'll grab 2.1 tonight and see if I can
reproduce it there.


Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around 

More information about the Twisted-Python mailing list