On Thu, 18 Aug 2005 23:36:58 +0200, Torsten Bronger <[EMAIL PROTECTED]> wrote:
>Hallöchen!
>
>When I use properties in new style classes, I usually pass get/set
>methods to property(), like this:
>
> x = property(get_x)
>
>If I overwrite get_x in a derived class, any access to x still calls
>the base get_x() method. Is there a way to get the child's get_x()
>method called instead?
>
>(I found the possibility of using an intermediate method _get_x
>which calls get_x but that's ugly.)
>
I think this idea of overriding a property access function is ugly in any case,
but you could do something like this custom descriptor (not tested beyond
what you see here):
>>> class RVP(object):
... def __init__(self, gettername):
... self.gettername = gettername
... def __get__(self, inst, cls=None):
... if inst is None: return self
... return getattr(inst, self.gettername)()
...
>>> class Base(object):
... def get_x(self): return 'Base get_x'
... x = RVP('get_x')
...
>>> class Derv(Base):
... def get_x(self): return 'Derv get_x'
...
>>> b = Base()
>>> d = Derv()
>>> b.x
'Base get_x'
>>> d.x
'Derv get_x'
But why not override the property x in the derived subclass instead,
with another property x instead of the above very questionable trick? I.e.,
>>> class Base(object):
... x = property(lambda self: 'Base get_x')
...
>>> class Derv(Base):
... x = property(lambda self: 'Derv get_x')
...
>>> b = Base()
>>> d = Derv()
>>> b.x
'Base get_x'
>>> d.x
'Derv get_x'
Regards,
Bengt Richter
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