The Drawbacks of @dataclass

[hades_ibex]

Simple question: what are the drawbacks of @dataclass that was introduced in 3.7? I'm not real experienced in Python, but why not make all classes a dataclass and simplify (i.e. get rid of) the __init__()?

[Gribouillis]

I don't use dataclass yet, but __init__() is needed technically: it is the place where arbitrary code can be executed every time an instance is created. Arbitrary code can be much more than simply members initialization.

[snippsat]

I have a tutorial here

what are the drawbacks of @dataclass that was introduced in 3.7?

I don't know if there any drawback is a new way to generate code for classes.
Example doing this,it's like writing 60 lines of code doing it without @dataclass.
Now is __init__(), __repr__(), __eq__(), __lt__(), __le__(), __gt__(), _ge__(), __setattr__(), __delattr__() generated.

from dataclasses import dataclass, field
from decimal import Decimal
 
@dataclass(order=True, frozen=True)
class Vehicle:
    kind: str = field(compare=False)
    name : str = field(compare=False)
    price: Decimal

I have not used @dataclass other than small test,i can see usefulness in some cases where need immutability,hashability and sorting.
Then a lot code is generated for you.

[micseydel]

I would say that generally there are not disadvantages. Technically, code generation is going to cost CPU and memory, but I doubt (unless you have a ton of dataclasses) that this would be an issue.

I've used them and really like them. Pro-tip: there's a __post_init__ method if you still need __init__ behavior in your dataclass :)