[vtk-developers] [vtkusers] More on VTK 5.0.4: hashing vtk class objects broken?

[David Gobbi]

I can't reproduce this on my system.  For me, the hash function works
just fine on VTK classes and instances in VTK 5.10.1.

Can a few other python users try this?

 - David


On Mon, Apr 29, 2013 at 1:14 PM, E. Tadeu <e.tadeu at gmail.com> wrote:
> This problem is still happening, I've just tested it with Python 2.7.3 and
> VTK 5.10.1.
>
> I've debugged it inside CPython, and this is what I found:
>
>     In object.c(1100): calling PyObject_Hash(PyObject *v = vtkObject)
>
>       PyTypeObject *tp = v->ob_type; // tp is 'vtkclass' from
> 'vtkCommonPython'
>
>     It calls, in line 1111: PyType_Ready(tp)
>
>       (Which seems it should've been called before)
>
>     In PyType_Ready, typeobject.c(4028), it calls:
>
>       mro_internal(type)
>
>     Which fails, because the type does not have the 'mro' attribute.
>
>
>   I've created an issue here: http://vtk.org/Bug/view.php?id=14037
>
>   Thanks!
>
>
>
> On Wed, May 27, 2009 at 10:56 AM, Berk Geveci <berk.geveci at kitware.com>
> wrote:
>>
>> This is definitely not intentional. Furthermore, I can't reproduce it
>> on cvs head. Do you know what caused the problem between 5.0.3 and
>> 5.0.4. Also, can you try 5.4 as I don't think we support 5.0 anymore?
>>
>> -berk
>>
>> On Wed, May 27, 2009 at 1:19 AM, Carlos Scheidegger
>> <cscheid at sci.utah.edu> wrote:
>> > Here's a simpler way to trigger the issue I just mentioned. The core
>> > problem
>> > is related to generating a hash from the vtk class object. On VTK 5.0.3
>> > (and
>> > Python 2.5.2), I get this:
>> >
>> >>>> import vtk
>> >>>> hash(vtk.vtkObject)
>> > 140169743808624
>> >>>> id(vtk.vtkObject)
>> > 140169743808624
>> >
>> > This seems to me the correct behavior. On VTK 5.0.4 (and Python 2.6.2),
>> > I
>> > get this:
>> >
>> >>>> hash(vtk.vtkObject)
>> > Traceback (most recent call last):
>> >  File "<stdin>", line 1, in <module>
>> > AttributeError: mro
>> >>>> id(vtk.vtkObject)
>> > 3083232608L
>> >
>> > Is this an intended change? It is very convenient to use vtk classes in
>> > python dictionaries...
>> >
>> > Thanks!
>> > -carlos