Home Original page

[Python-Dev] Check dict implementation details

Nick Coghlan ncoghlan at gmail.com
Sat Oct 8 23:14:42 EDT 2016 
On 8 October 2016 at 20:01, Serhiy Storchaka <storchaka at gmail.com> wrote:
> Since dict is ordered in CPython 3.6, it can be used instead of OrderedDict
> in some places (e.g. for implementing simple limited caches). But since this
> is implementation detail, it can't be used in the stdlib unconditionally.
> Needed a way to check whether dict is ordered.

As Raymond suggests, if order actually matters for a given use case,
then use collections.OrderedDict unconditionally without worrying
about the behaviour of the default dict implementation.

In addition to reducing code churn and improving cross-version and
cross-implementation compatibility, doing that also lets the *reader*
of the code know that the key iteration order matters.

Cheers,
Nick.

-- 
Nick Coghlan   |   ncoghlan at gmail.com   |   Brisbane, Australia
More information about the Python-Dev mailing list