subclassing versus object redefinition
Roald de Vries
downaold at gmail.com
Tue Aug 3 17:31:07 CEST 2010
On Aug 3, 2010, at 4:38 PM, wheres pythonmonks wrote:
> I think that the crux of the matter is in points #3, #4, and #5 that
> you raised:
I think #2 is important too: a program is supposed to do what you
expect, and I don't expect instantiation of an ABC.
> On #3: Not clear that all possible specializations warrant
> factorization into a class. Indeed, this may result in "premature
> abstraction" -- and make the code less clear. Also, it will freeze in
> the base classes, making future refactoring a headache.
I agree (for small specializations only).
> On #4: Unless I misunderstood something, there is nothing in python
> that ensures that a class definition is localized. So, putting
> definitions in classes, does not guarantee that the definition is at a
> single location in the code.
That's right, but with classes it is possible (and encouraged) to keep
things in a single location. The other option necessarily puts things
where I don't expect them.
> 5) why would you want a thinner class hierarchy?
> The yo-yo anti-patten:
> I have a pretty strong preference for using a small number of useful
> objects, instead of having code littered with objects strewn across
> the namespace.
I see the point, but I would like to remark that if a program does
what you expect, you won't need to understand the whole inheritance
> Maybe there is a Python ABC tutorial out there that can enlighten me?
PS: most people in this list prefer not top posting
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