Question

I have a subclass and I want it to not include a class attribute that’s present on the base class.

I tried this, but it doesn’t work:

>>> class A(object):
...     x = 5
>>> class B(A):
...     del x
Traceback (most recent call last):
  File "<pyshell#1>", line 1, in <module>
    class B(A):
  File "<pyshell#1>", line 2, in B
    del x
NameError: name 'x' is not defined

How can I do this?

Answer 1

Think carefully about why you want to do this; you probably don’t. Consider not making B inherit from A.

The idea of subclassing is to specialise an object. In particular, children of a class should be valid instances of the parent class:

>>> class foo(dict): pass
>>> isinstance(foo(), dict)
... True

If you implement this behaviour (with e.g. x = property(lambda: AttributeError)), you are breaking the subclassing concept, and this is Bad.