alt Hacker NewsCan someone ELI5 the core difference between this and named tuples, for someone who is not deep into Python? ChatGPT's answer boiled down to: unordered (this) vs ordered (NTs), "arbitrary keys, decided at runtime" vs "fixed set of fields decided at definition time" (can't an NT's keys also be interpolated from runtime values?), and a different API (`.keys()`, `.items()`), etc (I'm just giving this as context btw, no idea if there's inaccuracies in these).
So could this also have been approached from the other side, as in making unordered NamedTuples with support for the Mapping API? The line between dictionaries and named tuples and structs (across various languages) has always seemed a bit blurry to me, so I'm trying to get a better picture of it all through this.
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The key difference is what the GPT outlined: tuples have order for the fields and named tuples are not indexed by the name, but instead a field accessor is used, i.e. foo.bar vs foo["bar"]. In addition namedtuples can be indexed using that order like tuples can (foo[0]), which clearly isn't possible with dicts and would be quite confusing if dict had integer key.
So I think the differences aren't great, but they are sufficient. A frozendict is not going to be indexable by an integer. Python already has an abstract type for this, for mostly the use of type checking I imagine: https://docs.python.org/3/glossary.html#term-mapping
Documentation for namedtuple: https://docs.python.org/3/library/collections.html#collectio...
On top of generating types dynamically being slow and bad as quietbritishjim said, “str values that also happen to be valid identifiers” is a very limiting dict key requirement.
The values in tuples cannot change. The values that keys point to in a frozen dict can?
But yeah I'd be in favour of something that looked a lot like a named tuple but with mutable values and supporting [name] access too. And of course some nice syntactic sugar rather like dicts and sets have with curly brackets today.
I think you could have asked this same comment w/o mentioning ChatGPT and you wouldn't have been downvoted to oblivion in 3 minutes
I don't see anything wrong with your asking to understand
> arbitrary keys, decided at runtime" vs "fixed set of fields decided at definition time" (can't an NT's keys also be interpolated from runtime values?)
If you want to create a named tuple with arbitrary field names at runtime then you need to create a new named tuple type before you create the instance. That is possible, since Python is a very dynamic language, but it's not particularly efficient and, more importantly, just feels a bit wrong. And are you going to somehow cache the types and reuse them if the field names match? It's all a bit of a mess compared to just passing the entries to the frozendict type.