[vtk-developers] vtkInteratorStyle python subclass instantiation: TypeError: method requires a string argument

[David Lonie]

Thanks David. It looks like I can easily refactor the argument out in this
case, so I'll just do that in the meantime.

On Thu, Aug 27, 2015 at 10:09 AM, David Gobbi <david.gobbi at gmail.com> wrote:

> Hi David,
>
> Yes, it seems to be a bug related to the py3k modifications.  I believe
> that the swig-pointer initializer is still used in some places (it allows a
> person to create a python-wrapped VTK object, if all they have is a pointer
> to the object).
>
> I'm going away for a few days but I'll take a look when I get back.
>
>  - David
>
>
> On Thu, Aug 27, 2015 at 7:56 AM, David Lonie <david.lonie at kitware.com>
> wrote:
>
>> On Wed, Aug 26, 2015 at 3:02 PM, David Lonie <david.lonie at kitware.com>
>> wrote:
>>
>>> I'm updating some code for a client to use current VTK master, and
>>> there's an error while instantiating a python class that derives from
>>> vtkInteractorStyle. It seems to be related to __init__ taking an extra
>>> parameter which is used by the subclass to initialize some internals.
>>>
>>> A minimal example that reproduces the error:
>>>
>>> test.py:
>>> import vtk
>>>
>>> class MyInteractorStyle(vtk.vtkInteractorStyleUser):
>>>   def __init__(self, arg):
>>>     pass
>>>
>>> obj = MyInteractorStyle(2)
>>>
>>> $ vtkpython test.py
>>> Traceback (most recent call last):
>>>   File "/tmp/test.py", line 7, in <module>
>>>     obj = MyInteractorStyle(2)
>>> TypeError: method requires a string argument
>>>
>>> Removing the extra argument from __init__ will make the error go away.
>>>
>>> This worked a few months ago last time we bumped their VTK version. Is
>>> this a bug?
>>>
>>
>> It looks like the issue is in PyVTKObject_New, which treats all __init__
>> arguments as SWIG pointers for object initialization. I'm not familiar with
>> the usecase for that, is there some additional check we can perform to pass
>> over regular arguments?
>>
>> Dave
>>
>
>
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