[Python-Dev] Re: [Python-checkins] python/dist/src/Modulesheapqmodule.c, 1.1, 1.2

Guido van Rossum guido at python.org
Sat Nov 15 16:56:39 EST 2003

> > I thought the point of the current interface was that we could use
> > containers other than lists as long as they defined pop and append
> > methods.
> It would need __len__(), __getitem__(), __setitem__(), append(), and
> pop().  Right now, any list of subclass of list will do.  That helps the
> current implementation run faster.
> I think polymorphism is more important for the contents of the container
> rather than the container itself.  The objects inside the container need
> only define __le__().

Well, of course.  There *is* the theoretical objection that the old
heapq.py would work with any mutable sequence supporting append() and
pop() -- but I expect that is indeed purely a theoretical objection.

When I first introduced heapq.py, I briefly considered making it a
list subclass, but it didn't seem worth it (especially since the class
version would likely be slower).  But maybe for the C implementation
this makes more sense, especially since it only allows lists or list
subclasses anyway...?

--Guido van Rossum (home page: http://www.python.org/~guido/)

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