Question about subclassing - version 2

[Bruno Desthuilliers]

Maric Michaud a écrit :
> Le vendredi 08 septembre 2006 10:15, Bruno Desthuilliers a écrit :
> 
>>You
>>mentioned NotImplementedError, which is indeed the usual way to make
>>something "abstract" in Python.
> 
> 
> Hummm, some more thoughts about this.
> 
> I can imagine class hierarchies where the presence of not implemented methods 
> doesn't mean that the class is actually an abstract one.

I can imagine this too - as well as I can imagine the nightmarish 
spaghetti code that could use this class hierarchie.

> Even if partial 
> implementation is not a common scheme it can save you from writing a lot of 
> classes.

A partial implementation should return default values, not raise (aka 
NullObjectPattern). Well, IMHO at least.

(snip)

> And this can become a true spider net for more complicated cases. Obviously, 
> in practice we will choose alternatives to inheritance (strategies, 
> visitors, ...)

Composition/delegation...

> to work with such complex situations,

Indeed.