cpython/Lib/importlib/metadata/_meta.py

from typing import Protocol
from typing import Any, Dict, Iterator, List, Optional, TypeVar, Union, overload


_T = TypeVar("_T")


class PackageMetadata(Protocol):
    def __len__(self) -> int:
        ...  # pragma: no cover

    def __contains__(self, item: str) -> bool:
        ...  # pragma: no cover

    def __getitem__(self, key: str) -> str:
        ...  # pragma: no cover

    def __iter__(self) -> Iterator[str]:
        ...  # pragma: no cover

    @overload
    def get(self, name: str, failobj: None = None) -> Optional[str]:
        ...  # pragma: no cover

    @overload
    def get(self, name: str, failobj: _T) -> Union[str, _T]:
        ...  # pragma: no cover

    # overload per python/importlib_metadata#435
    @overload
    def get_all(self, name: str, failobj: None = None) -> Optional[List[Any]]:
        ...  # pragma: no cover

    @overload
    def get_all(self, name: str, failobj: _T) -> Union[List[Any], _T]:
        """
        Return all values associated with a possibly multi-valued key.
        """

    @property
    def json(self) -> Dict[str, Union[str, List[str]]]:
        """
        A JSON-compatible form of the metadata.
        """


class SimplePath(Protocol[_T]):
    """
    A minimal subset of pathlib.Path required by PathDistribution.
    """

    def joinpath(self) -> _T:
        ...  # pragma: no cover

    def __truediv__(self, other: Union[str, _T]) -> _T:
        ...  # pragma: no cover

    @property
    def parent(self) -> _T:
        ...  # pragma: no cover

    def read_text(self) -> str:
        ...  # pragma: no cover