Re: Problem with sub-classing

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

.

Relevant Pages

  • Re: Problem with sub-classing
    ... Okay, that make sense. ... > instance as first argument (got bbExportGranules instance instead) ... > class bbExportGranules(bbExportMeta, bbExportClusters, ... def method: pass ...
    (comp.lang.python)
  • Problem with sub-classing
    ... I have this problem when subclassing classes where I get this error: ... instance as first argument (got bbExportGranules instance instead) ... I have class bbExportGranules ...
    (comp.lang.python)