because PyLance & MyPy & friends tend to pretend X is init'ted across the whole scope where it is declared

snippet.py

import argparse
import dataclasses
import functools


@dataclasses.dataclass
class MainArgs:
    q: int | None
    v: int | None


@dataclasses.dataclass
class MainTable:

    args: MainArgs

    quietude: int
    verbosity: int
    loudness: int

    def __init__(self, args) -> None:
        self.args = args

        self.quietude = self.q_to_quietude()
        self.verbosity = self.v_to_verbosity()

        self.loudness = self.props_to_loudness()

        # ugh, PyLance Standard & MyPy let us delete most Lines of 'def __init__'

    def __hash__(self) -> int:
        """Hope we never make more than one Instance of this Class"""

        return 0

    def __repr__(self) -> str:

        items = list(vars(self).items())

        omitted_keys = "args".split()
        some_items = list(_ for _ in items if _[0] not in omitted_keys)
        rep_some_items = list(f"{k}={v}" for k, v in some_items)

        rep = "MainTable({})".format(", ".join(rep_some_items))

        return rep

    @functools.lru_cache(maxsize=None)
    def q_to_quietude(self) -> int:
        q = self.args.q

        quietude = q or 0  # as if not very hard, but nothing like as easy as this

        return quietude

    @functools.lru_cache(maxsize=None)
    def v_to_verbosity(self) -> int:
        v = self.args.v

        verbosity = v or 0  # same deal as with 'quietude ='

        return verbosity

    @functools.lru_cache(maxsize=None)
    def props_to_loudness(self) -> int:  # as if lots of complex slow work
        quietude = self.quietude
        verbosity = self.verbosity

        loudness = max(0, min(3, verbosity - quietude))

        return loudness


def main() -> None:

    # Auto-complete intensely abbreviated Input

    args = parse_args_or_quit()  # often prints help and exits
    print(args)

    mtable = MainTable(args)
    print(mtable)

    # Work up recommendations from complete Input

    way_way_way_verbose = mtable.loudness >= 3
    print(f"{way_way_way_verbose=}")


def parse_args_or_quit() -> MainArgs:

    parser = argparse.ArgumentParser()
    parser.add_argument("-q", action="count", help="say less")
    parser.add_argument("-v", action="count", help="say more")

    ns = parser.parse_args()  # often prints help and exits

    args = MainArgs(
        q=ns.q,
        v=ns.v,
    )

    return args

    # often prints help and exits


main()