ordered set 2
Hi, Raymond.
Thank you for your detailed response and I'm sorry about the late reply.
All of your points make sense to me. My implementation has not been
battle-tested yet.
As I wrote in a previous mail, there is only one benchmark in
pyperformance was affected significantly. (M
Antoine Pitrou wrote:
On a more abstract level, set and dict are both content-addressed
collections parametered on hash and equality functions.
Indeed. It's been said that a set is like "half a dict", and
this is why sets were implemented using dicts in the old days.
It's kind of an obvious th
On Thu, Feb 28, 2019 at 10:58 PM Antoine Pitrou wrote:
> Some of them may be coming from C++, where the respective
> characteristics of set and map (or unordered_set and
> unordered_multimap) are closely related. I'm sure other languages
> show similar analogies.
>
> On a more abstract level, set
> On 2019-02-28, at 12:56 , Antoine Pitrou wrote:
>
> On Thu, 28 Feb 2019 22:43:04 +1100
> Steven D'Aprano wrote:
>> On Wed, Feb 27, 2019 at 02:15:53PM -0800, Barry Warsaw wrote:
>>
>>> I’m just relaying a data point. Some Python folks I’ve worked with do
>>> make the connection between dict
On Thu, 28 Feb 2019 22:43:04 +1100
Steven D'Aprano wrote:
> On Wed, Feb 27, 2019 at 02:15:53PM -0800, Barry Warsaw wrote:
>
> > I’m just relaying a data point. Some Python folks I’ve worked with do
> > make the connection between dicts and sets, and have questions about
> > the ordering guaran
On Wed, Feb 27, 2019 at 02:15:53PM -0800, Barry Warsaw wrote:
> I’m just relaying a data point. Some Python folks I’ve worked with do
> make the connection between dicts and sets, and have questions about
> the ordering guarantees of then (and how they relate).
Sets and dicts are not related b
On Thu, Feb 28, 2019 at 7:23 AM Henry Chen wrote:
> If sets were ordered, then what ought pop() return - first, last, or
> nevertheless an arbitrary element? I lean toward arbitrary because in
> existing code, set.pop often implies that which particular element is
> immaterial.
>
>
dict.popitem()
If sets were ordered, then what ought pop() return - first, last, or
nevertheless an arbitrary element? I lean toward arbitrary because in
existing code, set.pop often implies that which particular element is
immaterial.
On Wed, Feb 27, 2019 at 2:18 PM Barry Warsaw wrote:
> On Feb 27, 2019, at 1
On Feb 27, 2019, at 13:54, Chris Barker via Python-Dev
wrote:
>
> A mapping and a set type really don't have much to do with each other other
> than implementation -- anyone that isn't familiar with python C code, or hash
> tables in general, wouldn't likely have any expectation of them having
On Tue, Feb 26, 2019 at 3:43 PM Barry Warsaw wrote:
> The behavior differences between dicts and sets is already surprising to
> many users, so we should be careful not to make the situation worse.
>
It's a nice to have, but other than the fact that we all used to use a dict
when we really want
On Feb 26, 2019, at 13:02, Raymond Hettinger
wrote:
> * I gave up on ordering right away. If we care about performance, keys can
> be stored in the order added; but no effort should be expended to maintain
> order if subsequent deletions occur. Likewise, to keep set-to-set operations
> effi
Le mar. 26 févr. 2019 à 17:33, INADA Naoki a écrit :
> My company gives me dedicated Linux machine with Core(TM) i7-6700.
> So I think it's not issue of my machine.
Oh great :-)
> perf shows this line caused many page fault.
> https://github.com/python/cpython/blob/c606a9cbd48f69d3f4a09204c781dd
Quick summary of what I found when I last ran experiments with this idea:
* To get the same lookup performance, the density of index table would need to
go down to around 25%. Otherwise, there's no way to make up for the extra
indirection and the loss of cache locality.
* There was a small win
> On Feb 26, 2019, at 3:30 AM, INADA Naoki wrote:
>
> I'm working on compact and ordered set implementation.
> It has internal data structure similar to new dict from Python 3.6.
>
> On Feb 26, 2019, at 3:30 AM, INADA Naoki wrote:
>
> I'm working on compact and ordered set implementation.
On Wed, Feb 27, 2019 at 12:37 AM Victor Stinner wrote:
>
> Le mar. 26 févr. 2019 à 12:33, INADA Naoki a écrit :
> > - unpickle_list: 8.48 us +- 0.09 us -> 12.8 us +- 0.5 us: 1.52x slower
> > (+52%)> ...
> > ...
> > unpickle and unpickle_list shows massive slowdown. I suspect this slowdown
> > i
Le mar. 26 févr. 2019 à 12:33, INADA Naoki a écrit :
> - unpickle_list: 8.48 us +- 0.09 us -> 12.8 us +- 0.5 us: 1.52x slower
> (+52%)> ...
> ...
> unpickle and unpickle_list shows massive slowdown. I suspect this slowdown
> is not caused from set change. Linux perf shows many pagefault is happ
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