Pb with descriptor and super ...

[Erwan Adam]

Hi all,

I have a problem with the use of descriptors
and super. The file is :

# ---------------

class Desc(object):
     def __init__(self, class_name):
         self.class_name = class_name
         return
     def __get__(self, obj, typ):
         print "Desc.__get__ : class_name is %s, obj is %s and typ is 
%s"%(self.class_name, obj, typ)
         return
     pass

class A(object):
     attr = Desc("A")
     pass

class B(A):
     attr = Desc("B")
     pass

b = B()

print "-------"
print "Getting b.attr ..."
print "I hope that  : class_name is B, obj is b and typ is B"
b.attr
print "-------"
print "Getting super(B, b).attr ..."
print "I hope that  : class_name is A, obj is b and typ is A but it is 
not the case !"
super(B, b).attr
print "-------"

# -----------

and the result is :

-------
Getting b.attr ...
I hope that  : class_name is B, obj is b and typ is B
Desc.__get__ : class_name is B, obj is <__main__.B object at 0xb7b1f8ec> 
and typ is <class '__main__.B'>
-------
Getting super(B, b).attr ...
I hope that  : class_name is A, obj is b and typ is A but it is not the 
case !
Desc.__get__ : class_name is A, obj is <__main__.B object at 0xb7b1f8ec> 
and typ is <class '__main__.B'>
-------

I expected that when getting super(B, b).attr, typ is A, but it is not
the case ...

python used :

[adam at is111902 /home/adam/Work/Python]> python
Python 2.4.3 (#2, Sep 18 2006, 21:07:35)
[GCC 4.1.1 20060724 (prerelease) (4.1.1-3mdk)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
 >>>


Best regards,


           E.A.