Inheritance/Late Private Binding

[Jeremy Moles]

class BaseClass:
def __init__(self):
self.__data = None

def getMember(self):
return self.__data

class GoodSubClass(BaseClass):
def __init__(self):
BaseClass.__init__(self)

class BadSubClass(BaseClass):
def __init__(self):
self.__x = None

gsc = GoodSubClass()
print dir(gsc)
gsc.getMember()

bsc = BadSubClass()
print dir(bsc)
bsc.getMember()

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Forgive me if this topic has been brought up before, but I was curious
as to why I was getting this behavior and was hoping someone
knowledgeable could explain.

I "feel" like even without the explicit call to a simple base ctor(),
mangling should still happen correctly. This doesnt, however, seem to be
the case...

Of note: simply doing a 'pass' in BadSubClass seems to be sufficient as
well; so, it has something to do with defining a ctor() in the child and
not explicitly invoking the parent's ctor.

 

[Michael Hoffman]

Forgive me if this topic has been brought up before, but I was curious
as to why I was getting this behavior and was hoping someone
knowledgeable could explain.

What behavior?

I "feel" like even without the explicit call to a simple base ctor(),
mangling should still happen correctly. This doesnt, however, seem to be
the case...

How is mangling happening incorrectly?

Functions in base classes that are overridden by subclasses aren't
called implicitly.

Also, I think using the term "ctor()" is confusing since you don't seem
to have anything callable named ctor. As for the constructor, just call
it __init__, it will avoid confusion with __new__.