[Twisted-Python] Python properties and pb.Referenceable...

Jasper jasper at peak.org
Thu Mar 10 09:26:37 EST 2005

James Y Knight wrote:

> On Mar 9, 2005, at 9:15 PM, Jasper wrote:
>> Jasper wrote:
>>> I'm trying to set a python property on a PB client descended from 
>>> pb.Referenceable, but it seems that properties don't work on old 
>>> style classes and that Referenceable is descended from Jellyable, an 
>>> old style class.  Moreover, I see this is still true for 2.0.0a2...
>>> Is there any intention of switching to new classes, or should I just 
>>> hack around this?
>> Turns out that the simple hack of Client( object, pb.Referenceable ) 
>> seems to work.  Sorry for the trouble!
> You really don't want to do that. Then, if pb.Referenceable ever does 
> become a new-style class (for example because a new version of python 
> gets rid of oldstyle classes, or because twisted is changed), then 
> you'll get an MRO construction error. Always put object last in the 
> inheritance line.
> E.g.:
> class Foo: pass
> class Bar(object, Foo): pass # Fine
> class Foo(object): pass
> class Bar(object, Foo): pass # BOOM

Actually, I prefer it to blow up to help remember when to stop using 
this ugly comment requiring hack..

I have absolute control over the version of Python and Twisted I'm 
using, and so the worst that can happen is that I'll have to change a 
single line of code when and if I upgrade to such a version of Twisted 
or Python.


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