[Python-Dev] [RFC] Removing pure Python implementation of OrderedDict

[Zachary Ware]

On Tue, Sep 5, 2017 at 12:13 PM, Eric Snow <ericsnowcurrently at gmail.com> wrote:
> On Tue, Sep 5, 2017 at 1:38 AM, INADA Naoki <songofacandy at gmail.com> wrote:
>> Like that, how about removing OrderedDict Pure Python implementation
>> from stdlib and require it to implementation?
>
> -1
>
> Like Antoine, I consider the pure Python implementation to be
> valuable.  Furthermore, the pure Python implementation is the
> reference, so its behavior is idiomatic.

-1 as well, I'm in favor of keeping Python implementations of things
implemented in C, no matter the order in which they are added.

>> ### Less maintenance cost of test_ordered_dict.
>>
>> [snip]
>
> I don't find this to be a strong argument.  If there are concerns with
> the reference behavior then those should be addressed rather than used
> to justify removing the implementation.

I agree here as well.  We have plenty of things implemented in both
Python and C, and have helpers in test.support to make it (relatively,
at least) easy to test both.

PEP 399 is also relevant here, I think.

-- 
Zach