# Dataclass fields ## Basic ```py from dataclasses import dataclass, field @dataclass class Member: name: str role: str = field(default="user") tag: str | None = field(default=None, init=False) # TODO: this should not include the `tag` parameter, since it has `init=False` set # revealed: (self: Member, name: str, role: str = Literal["user"], tag: str | None = None) -> None reveal_type(Member.__init__) alice = Member(name="Alice", role="admin") reveal_type(alice.role) # revealed: str alice.role = "moderator" # TODO: this should be an error, `tag` has `init=False` bob = Member(name="Bob", tag="VIP") ``` ## The `field` function ```py from dataclasses import field reveal_type(field(default=1)) # revealed: Literal[1] ```