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Comment by claytonjy | Hacker News Reader

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claytonjy·

My general rule is, if I have a dict with a fixed set of keys, it should be a dataclass. Problem solved!

Then if I need to send or receive it, it's an easy conversion to a Pydantic BaseModel.

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And the dataclass serves as documentation for the available attributes and type safety..

It's really the way to go, takes a minute or two to define and saves so much headaches in the long run.

100%. I don’t understand the obsession with bending dicts into something they are inherently bad at when actual alternatives in dataclasses and Pydantic models right there.

Can dataclasses be serialized just as easily?

Yes via pickle.

Or for JSON, dataclasses_json

Be aware that pickle is unsafe (as documented near the top of https://docs.python.org/3/library/pickle.html), so prefer other serialization formats except between trusted processes

I can't remember the last time I _wanted_ to pickle something. Parquet and JSON pretty much cover it for me. I guess pickling made more sense before tools like Pydantic were good and popular?

If I want all the python-specific nuance on disk, I know I'm in a bad place!

I use pickle to serialize RPC requests between internal services. Nothing beats it in terms of speed and ease of use.

Yep! Both msgspec (https://jcristharif.com/msgspec/supported-types.html#datacla...) and orjson support encoding dataclasses to JSON natively.

In addition to the already-mentioned suggestions, you can also use marshmallow schemas to serialise complex objects, and there's even a package to autogen marshmallow schemas from dataclasses: https://pypi.org/project/marshmallow-dataclass/

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