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A “frozen” dictionary for Python

(lwn.net)
191 points jwilk | 6 comments | 11 Dec 25 09:51 UTC | HN request time: 0.001s | source | bottom
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pansa2 ◴[11 Dec 25 12:45 UTC] No.46230704[source]▶
I wonder whether Raymond Hettinger has an opinion on this PEP. A long time ago, he wrote: "freezing dicts is a can of worms and not especially useful".

https://mail.python.org/pipermail/python-dev/2006-February/0...

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mvanbaak ◴[11 Dec 25 13:06 UTC] No.46230899[source]▶
This was 19 (almost) 20 years ago. As stated in the lwn.net article, a lot of concurrency has been added to python, and it might now be time for something like a frozendict.

Things that were not useful in 2006 might be totally useful in 2026 ;P

Still, like you, I'm curious wether he has anything to say about it.

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1. aewens ◴[11 Dec 25 13:39 UTC] No.46231217[source]▶
I think Raymond Hettinger is called out specially here because he did a well known talk called [Modern Dictionaries](https://youtu.be/p33CVV29OG8) where around 32:00 to 35:00 in he makes the quip about how younger developers think they need new data structures to handle new problems, but eventually just end up recreating / rediscovering solutions from the 1960s.

“What has been is what will be, and what has been done is what will be done; there is nothing new under the sun.”

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2. sesm ◴[11 Dec 25 13:59 UTC] No.46231435[source]▶
Since that time HAMT was invented and successfully used in Scala and Clojure, so this talk didn't age well.
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3. Someone ◴[11 Dec 25 14:38 UTC] No.46231924[source]▶
Wikipedia (https://en.wikipedia.org/wiki/Hash_array_mapped_trie) links to the paper describing HAMT (https://infoscience.epfl.ch/server/api/core/bitstreams/f66a3...) and claims that is from 2000. That talk is from 2016.
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4. ndr ◴[11 Dec 25 15:04 UTC] No.46232272{3}[source]▶
HAMT weren't immutable/persistent until Clojure though: https://en.wikipedia.org/wiki/Persistent_data_structure#Pers...

Still well before the talk.

5. zelphirkalt ◴[11 Dec 25 15:58 UTC] No.46232996{3}[source]▶
Do you know of any implementation, that is well annotated/commented, so that it is easy to understand?
6. kzrdude ◴[13 Dec 25 14:23 UTC] No.46254706[source]▶
I think he was always reluctant to add features, and his version of Python would be slimmer, beautiful, and maybe 'finished'. His voice is definitely not guiding the contemporary Python development, which is more expansionist in terms of features.