Problem with sub-classing

[Peter Otten]

Bernard Lebel wrote:

> Hello,
> 
> I have this problem when subclassing classes where I get this error:
> 
> Traceback (most recent call last):
> 
> File "<Script Block >", line 344, in BBExportElementGranules_Execute
>     from bb_pipeline import bb_exportelementgranules
> 
> File
>
"\\Linuxserver\ANIMATION\XSI\WORKGROUP_ANIMATION\Data\Scripts\bb_pipeline\bb_exportelementgranules.py",
> line 101, in ?
>     oWriter = bbExportGranules()
> 
> File
>
"\\Linuxserver\ANIMATION\XSI\WORKGROUP_ANIMATION\Data\Scripts\bb_pipeline\bb_granules\bb_granuleexport\bb_granuleexport_element.py",
> line 73, in __init__
>     bbExportMeta.__init__( self )
> 
> TypeError: unbound method __init__() must be called with bbExportMeta
> instance as first argument (got bbExportGranules instance instead)
>  - [line 343 in
>
\\Linuxserver\ANIMATION\XSI\WORKGROUP_ANIMATION\plugins\bb_pipeline\bb_pipeline_py.py]
> 
> 
> In normal English:
> 
> I have class bbExportGranules
> bbExportGranules is a sub-class of 6 other classes
> In the __init__() of bbExportGranules class, I call the __init__() of
> 5 of these super-classes.
> 
> 
> The init of bbExportGranules:
> 
> class bbExportGranules( bbExportMeta, bbExportClusters,
> bbExportMaterials, bbExportKinematics, bbExportModels, bbExportMetaToc
> ):
> 
> def __init__( self ):
> 
> bbExportMeta.__init__( self )
> bbExportClusters.__init__( self )
> bbExportMaterials.__init__( self )
> bbExportKinematics.__init__( self )
> bbExportModels.__init__( self )
> 
> 
> And the bbExportMeta class (the error is raised when bbExportGranules
> is subclassing that one):
> 
> class bbExportMeta:
> 
> def __init__( self ):
> 
> self.iPreviousAssetVersion = gec.iNOPREVIOUSASSETVERSION
> self.iCurrentAssetVersion = gec.iMINCURRENTASSETVERSION
> self.sPreviousAssetProject = xsi.getdefaultproject()
> 
> 
> 
> 
> Any suggestion? I really, really don't see what I'm doing wrong here,
> especially that it actually used to work!

Change bbExportGranules to

class bbExportGranules( bbExportMeta, bbExportClusters,
bbExportMaterials, bbExportKinematics, bbExportModels, bbExportMetaToc
):
        
        def __init__(self,  bbExportMeta=bbExportMeta): # the only change
                
                bbExportMeta.__init__( self )
                bbExportClusters.__init__( self )
                bbExportMaterials.__init__( self )
                bbExportKinematics.__init__( self )
                bbExportModels.__init__( self )

If it then starts to work again you are probably rebinding bbExportMeta
later in your script, e. g:

>>> class A:
...     def method(self): pass
...
>>> class B(A):
...     def method(self):
...             A.method(self)
...
>>> b = B()
>>> b.method() # no error
>>> class A: # rebinding A
...     def method(self): pass
...
>>> b.method() # oops
Traceback (most recent call last):
  File "<stdin>", line 1, in ?
  File "<stdin>", line 3, in method
TypeError: unbound method method() must be called with A instance as first
argument (got B instance instead)

One way to make that happen is to import the same file twice, once as part
of a package and once directly. Solution: never set a path into a
package...

Peter