import sys
from _typeshed import ReadOnlyBuffer
from types import TracebackType
from typing import TypeVar, overload
from typing_extensions import Self, TypeAlias

if sys.platform != "win32":
    _T = TypeVar("_T")
    _KeyType: TypeAlias = str | ReadOnlyBuffer
    _ValueType: TypeAlias = str | ReadOnlyBuffer

    class error(OSError): ...
    library: str

    # Actual typename dbm, not exposed by the implementation
    class _dbm:
        def close(self) -> None: ...
        def __getitem__(self, item: _KeyType) -> bytes: ...
        def __setitem__(self, key: _KeyType, value: _ValueType) -> None: ...
        def __delitem__(self, key: _KeyType) -> None: ...
        def __len__(self) -> int: ...
        def __del__(self) -> None: ...
        def __enter__(self) -> Self: ...
        def __exit__(
            self, exc_type: type[BaseException] | None, exc_val: BaseException | None, exc_tb: TracebackType | None
        ) -> None: ...
        @overload
        def get(self, k: _KeyType) -> bytes | None: ...
        @overload
        def get(self, k: _KeyType, default: _T) -> bytes | _T: ...
        def keys(self) -> list[bytes]: ...
        def setdefault(self, k: _KeyType, default: _ValueType = ...) -> bytes: ...
        # Don't exist at runtime
        __new__: None  # type: ignore[assignment]
        __init__: None  # type: ignore[assignment]
    def open(__filename: str, __flags: str = "r", __mode: int = 0o666) -> _dbm: ...