dataclass_constructor.py

from dataclasses import dataclass
from typing import Self

@dataclass
class Example:
    field1: str
    field2: str

    @classmethod
    def from_input_data(cls, data) -> Self:
        field1 = data.do_something()
        field2 = data.do_something_else()
        return cls(
            **{
                key: value
                for key, value in locals().items()
                if key in cls.__dataclass_fields__
            }
        )