[hamstergene]

As soon as I opened the article I pressed Cmd+F and searched for "dataclasses".

This article was correct and addressed a very real need in Python programming—for year 2016. By now it is obsolete and today's standard library module `dataclasses` does all of that and more.

[ttwwmm]

attrs classes still have several features that dataclasses don't, and likely never will, [like validators and converters](https://www.attrs.org/en/stable/why.html#data-classes). So it's not obsolete, particularly for anyone already relying on those features.

[nurettin]

dataclasses have methods for iterating fields and inspecting types, so any feature can be added. There is also the benefit of type checking. My grief with dataclasses is how I can't inherit from dataclasses with default fields without making all child class fields also have defaults.

[ericvsmith]

dataclasses author here.

Does the keyword-only feature in 3.10 help you at all?

[abdusco]

Wow, I was unaware of this feature. It appears there are 3 ways to declare fields as keyword-only.

    @dataclass(kw_only=True)
    class Birthday:
        name: str
        birthday: datetime.date

    # ---

    @dataclass
    class Birthday:
        name: str
        birthday: datetime.date = field(kw_only=True)

    # ---

    from dataclasses import KW_ONLY

    @dataclass
    class Point:
        x: float
        y: float
        _: KW_ONLY
        z: float = 0.0
        t: float = 0.0

https://docs.python.org/3/whatsnew/3.10.html#keyword-only-fi...

[muxator]

And a big thank you for the dataclasses module, and for making the life of the whole python community a little easier!

[nurettin]

Love it, thank you!

[joshuamorton]

Echoing the other commenter, attrs is generally superior to dataclasses (dataclasses is a feature-limited std library "backport" of attrs). It will be updated less often and support less stuff. The only real reason to use dataclasses is if you want to avoid a third-party dependency, which is sometimes valid but doesn't make the more featureful version "obsolete".

[dreamofkoholint]

Is there a reason those features weren't added to data classes?

I don't know much about attrs, only professionally coming to python since 3.7, but I'm not going to bring it in if there's something sufficient in the language

[joshuamorton]

Not really, other than they decided to keep data classes very minimal, as standard library comes with maintenance costs (you can't get rid of a feature once you add it), so they kept the strict features, since everyone uses those, and not the complex validation features.

[kissgyorgy]

attrs was first, dataclasses design is actually based on attrs! dataclasses is inferior in features and actually a shame because I see this ignorant attitude everywhere and I have to defend and explain attrs every time we need it.