Bug in Python?

Sven R. Kunze srkunze at mail.de
Sun Feb 28 05:24:00 EST 2016

On 27.02.2016 12:48, Terry Reedy wrote:
> On 2/27/2016 4:44 AM, Steven D'Aprano wrote:
>> On Sat, 27 Feb 2016 07:55 pm, Terry Reedy wrote:
>>> In other words, when that doc says *list*, it means a *list*.
>>> "To create a heap, use a list initialized to [], or you can transform a
>>> populated list into a heap via function heapify()."
>> [...]
>>> "A heap must be an instance of *list* (and not a subclass thereof).  To
>>> create a heap, start with [] or transform an existing list into a heap
>>> via function heapify()."
>> I think that's a sad decision. heapq ought to be able to handle any list
>> subclass, not just actual lists. Preferably it ought to handle 
>> duck-typed
>> lists too, anything with a list-like interface. It is okay if the 
>> optimized
>> C version only works with actual lists, and falls back to a slower 
>> Python
>> version for anything else.

I agree that it would increase comprehensibility. I took me a fair 
amount of time to see why things are not working as intended (and as you 
see I wasn't even close to the real explanation).

However, heapq might work well the way it is as long as you have the 
chance to get your hands on one of the other heap implementations out there.

> Propose that on the tracker, after checking previous issues.



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