just a little helper -- cast a tuple / list to this when you want to keep index NewType(int) straight

typed_index_sequence.py

from collections.abc import Iterator
from collections.abc import Sequence
from typing import Protocol
from typing import runtime_checkable

@runtime_checkable
class TypedIndexSeq[K: int, V](Protocol):
    """
    Sequence-like object where indexed access is restricted to a typed int-like key.
    Pair with NewType(int) for K to keep from crossing up indexes.
    """

    def __len__(self) -> int: ...
    def __iter__(self) -> Iterator[V]: ...

    @overload
    def __getitem__(self, idx: K) -> V: ...
    @overload
    def __getitem__(self, idx: slice) -> Sequence[V]: ...