Re: [Jython-users] Issue with None and Serialization

[Samuele P. <pe...@in...>]

From: chuck clark <cc...@zi...>
> I thought the problem might be that between serializing/deserializing I
> might somehow be getting a different instance of PyNone but this isn't
> the case as evidenced below when I inspect the objects in the
> interpreter after running th code above
> >>> type(a.attr)
> <jclass org.python.core.PyNone at 334527779>
> >>> type(b.attr)
> <jclass org.python.core.PyNone at 334527779>
> 

No, you're right it is a *bug* and your hypothesis is right,
only the above give you the "address" of the PyNone class.
The following is more revealing:
>>> execfile("test.py")
Testing initial object...
attr is None: 1
attr type is: org.python.core.PyNone
attr == None: 1
Testing deserialized object...
attr is None: 0
attr type is: org.python.core.PyNone
attr == None: 0
>>> id(None)
6503157
>>> id(a.attr)
6503157
>>> id(b.attr)
8302342

It is a problem with singletons serialization, it has gone
unnoticed until your report, it affects None, Ellipsis etc

Thanks, Samuele Pedroni.