It's now the spec for 3.6+.
> #python news: @gvanrossum just pronounced that dicts are now guaranteed to retain insertion order. This is the end of a long journey.
https://twitter.com/raymondh/status/941709626545864704
More here:
https://www.reddit.com/r/Python/comments/7jyluw/dict_knownor...
OrderedDicts are backwards-compatible and are guaranteed to maintain order after deletion.