[vik_nuckchady]

Hi,

i am trying to run the code at http://wiki.forum.nokia.com/index.ph...he_view_finder on an N95 and it is giving the following error the script is executed:

File "launcher.py", line 37, in <module>
execfile('default.py', default_namespace)
File "default.py", line 40, in <module>
class Camera( object, appuifw.Canvas ):
TypeError: Error when calling the metaclass bases
Cannot create a consistent method resolution order (MRO) for bases Canvas, object

Would anyone have an idea about how i can solve this problem ? I have only one version of python running on the phone according to the programs manager.

Thanks in advance
vik

[bogdan.galiceanu]

Hi,

That problem can be solved by removing "object" from the Camera class constructor. This line

class Camera( object, appuifw.Canvas ):

becomes

class Camera( appuifw.Canvas ):

[vik_nuckchady]

Thanks Bogdan for the prompt reply.

Could you tell me why removing 'object' solves the problem ? Is it that Canvas is already an 'object' in this case and, making Camera an object as well in addition to inheriting from Canvas is causing the MRO ? I do understand the reason behind of the TypeError (i.e the MRO) but, i fail to understand the cause of it in this case.

Thanks again

[bogdan.galiceanu]

To be honest, I'm not sure. This was the first time I encountered this error so I did a bit of searching with Google and found out it had to do with inheritance, though I wasn't able to understand exactly how. So I just took a shot and deleted "object" from the constructor and, luckily, it worked.

I did find this lengthy article though, which may explain it:
http://www.python.org/download/releases/2.3/mro/

[vik_nuckchady]

Hi again Bogdan,

I am suspecting that newer version of the Python runtime for S60 is employing different mechanism for implementing inheritance much like it has been for python 2.2 -> 2.3 (?)

Well, thanks again. Hopefully some answer will pop up in the near future

Cheers