Inheriting property functions

Diez B. Roggisch deets at nospam.web.de
Sat Oct 21 09:32:44 CEST 2006


Dustan schrieb:
> Looking at this interactive session:
> 
>>>> class A(object):
> 	def __init__(self, a):
> 		self.a = a
> 	def get_a(self): return self.__a
> 	def set_a(self, new_a): self.__a = new_a
> 	a = property(get_a, set_a)
> 
> 
>>>> class B(A):
> 	b = property(get_a, set_a)
> 
> 
> Traceback (most recent call last):
>   File "<pyshell#11>", line 1, in <module>
>     class B(A):
>   File "<pyshell#11>", line 2, in B
>     b = property(get_a, set_a)
> NameError: name 'get_a' is not defined
>>>> class B(A):
> 	b = a
> 
> 
> Traceback (most recent call last):
>   File "<pyshell#13>", line 1, in <module>
>     class B(A):
>   File "<pyshell#13>", line 2, in B
>     b = a
> NameError: name 'a' is not defined
> 
> B isn't recognizing its inheritence of A's methods get_a and set_a
> during creation.
> 
> Why am I doing this? For an object of type B, it makes more sense to
> reference the attribute 'b' than it does to reference the attribute
> 'a', even though they are the same, in terms of readability.

I think you are having a code smell here. However, this is how you do it:

class B(A):
     b = A.a


Diez



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