3 ms·

OrderedDicts have some convenience methods and features that ordinary dicts don't have.

rbanffy 2y ago
Also, dicts can become unordered at any time in the future. Right now the OrderedDict implementation is a thin layer over dict, but there are no guarantees it’ll always be that.
- wodenokoto 2y ago
  They can, but ordered dict can also become unordered in the future, should the steering committee decide. But seriously: It’s no longer an implementation detail that dictionaries are ordered in Python. It’s a specification of how Python works.
  - rbanffy 2y ago
    I missed that in the 3.7 release notes.
- judicious 2y ago
  There in lies another reason why OrderedDicts are still useful even in 3.12
  - rbanffy 2y ago
    Not really. It was pointed out that since 3.7 the order preserving behaviour is part of the spec for dicts.
    - judicious 2y ago
      I guess for most purposes, OrderedDicts are then obsolete, but I believe there are some extra convenience methods that they have, but I've only really needed to preserve order. Makes you think what other parts of Python have become obsolete.
- 3eb7988a1663 2y ago
  Not true as of 3.7[0] the insertion-order preservation nature of dict objects has been declared to be an official part of the Python language spec. [0] https://docs.python.org/3.7/whatsnew/3.7.html https://docs.python.org/3.7/whatsnew/3.7.html
  - rbanffy 2y ago
    Oh well... This is what I get to not look at release notes with lawyer eyes. Thanks for the correction.
- SuchAnonMuchWow 2y ago
  dict are ordered to keep argument order when using named arguments in function calling. So it would be a non-trivial breaking change to revert this now. I would argue that OrderedDict have more chances to be depreciated than dict becoming unordered again, since there is now little value to keep OrderedDict around now (and the methods currently specific to UnorderedDict could be added to dict).
wodenokoto 2y ago
Do you have any examples?
- heavyset_go 2y ago
  Check out the docs: https://docs.python.org/3/library/collections.html#collections.OrderedDict https://docs.python.org/3/library/collections.html#collectio...

Also, dicts can become unordered at any time in the future. Right now the OrderedDict implementation is a thin layer over dict, but there are no guarantees it’ll always be that.

wodenokoto 2y ago
They can, but ordered dict can also become unordered in the future, should the steering committee decide. But seriously: It’s no longer an implementation detail that dictionaries are ordered in Python. It’s a specification of how Python works.
- rbanffy 2y ago
  I missed that in the 3.7 release notes.
judicious 2y ago
There in lies another reason why OrderedDicts are still useful even in 3.12
- rbanffy 2y ago
  Not really. It was pointed out that since 3.7 the order preserving behaviour is part of the spec for dicts.
  - judicious 2y ago
    I guess for most purposes, OrderedDicts are then obsolete, but I believe there are some extra convenience methods that they have, but I've only really needed to preserve order. Makes you think what other parts of Python have become obsolete.
3eb7988a1663 2y ago
Not true as of 3.7[0] the insertion-order preservation nature of dict objects has been declared to be an official part of the Python language spec. [0] https://docs.python.org/3.7/whatsnew/3.7.html https://docs.python.org/3.7/whatsnew/3.7.html
- rbanffy 2y ago
  Oh well... This is what I get to not look at release notes with lawyer eyes. Thanks for the correction.
SuchAnonMuchWow 2y ago
dict are ordered to keep argument order when using named arguments in function calling. So it would be a non-trivial breaking change to revert this now. I would argue that OrderedDict have more chances to be depreciated than dict becoming unordered again, since there is now little value to keep OrderedDict around now (and the methods currently specific to UnorderedDict could be added to dict).

wodenokoto 2y ago

Do you have any examples?

heavyset_go 2y ago
Check out the docs: https://docs.python.org/3/library/collections.html#collections.OrderedDict https://docs.python.org/3/library/collections.html#collectio...