On Fri, May 9, 2008 at 3:20 PM, Joseph Turian <tu****@gmail.comwrote:
Could someone demonstrate how to implement the proposed solutions that
allow the property to be declared in the abstract base class, and
refer to a get function which is only implemented in derived classes?
One way is to have the property refer to a proxy that performs the
late binding, which might look something like this:
def _bar(self):
return self.bar()
prop = property(fget=_bar)
Another way is to declare properties using something like the
following indirectproperty class. I haven't thoroughly tested this,
so I don't know whether it works exactly right.
class indirectproperty(object):
def __init__(self, sget=None, sset=None, sdel=None):
self.sget = sget
self.sset = sset
self.sdel = sdel
def __get__(self, instance, owner):
if instance is not None:
fget = getattr(instance, self.sget)
else:
fget = getattr(owner, self.sget)
return fget()
def __set__(self, instance, value):
fset = getattr(instance, self.sset)
fset(value)
def __delete__(self, instance):
fdel = getattr(instance, self.sdel)
fdel()
class Foo(object):
def func(self): return "foo"
callfunc = indirectproperty(sget="func")
class Bar(Foo):
def func(self): return "bar"
