[Python-Dev] defaultdict proposal round three (original) (raw)

Delaney, Timothy (Tim) tdelaney at avaya.com
Tue Feb 21 03:10:21 CET 2006


"Martin v. Löwis" wrote:

Delaney, Timothy (Tim) wrote:

However, because Python uses duck typing, I tend to feel that subclasses in Python should be drop-in replacements. If it's not a drop-in replacement, then it should probably not subclass, but just use duck typing (probably by wrapping). Inheritance is more about code reuse than about polymorphism.

Oh - it's definitely no hard-and-fast rule. owever, I have found that usually people (including myself) only subclass when they want an is-a relationship, whereas duck typing is behaves-like.

In any case, Guido has produced a patch, and the tone of his message sounded like a Pronouncement ...

Tim Delaney



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