eq=True and fronze=True has __hash__ function

data_hash.py

from dataclasses import dataclass


@dataclass(frozen=True)
class Params:
    user_name: str
    age: int
    weight: float


if __name__ == '__main__':
    a = Params('Alice', 12, 34.5)
    b = Params('Bob', 40, 70.9)
    c = Params('Bob', 40, 70.9)
    print(hash(a))  # 6475419868813917241
    print(hash(b))  # -312248743948144481
    print(hash(c))  # -312248743948144481