How to set the value of dataclass field in __post_init__ when frozen=True?

Question

I\'m trying to create a frozen dataclass but I\'m having issues with setting a value from __post_init__. Is there a way to set a field value based on values from an

Answer 1

Use the same thing the generated __init__ method does: object.__setattr__.

def __post_init__(self):
    object.__setattr__(self, 'value', RANKS.index(self.rank) + 1)