General directory scanner implementation in pure Python

directory_scanner.py

class PathScanner:
    input_paths: list[str]
    allowed_extensions: tuple[str]

    def __init__(self, input_paths: list[str], allowed_extensions: tuple[str]) -> None:
        self.input_paths = input_paths
        self.allowed_extensions = allowed_extensions

    def fetch_paths(self) -> list[str]:
        result: list[str] = []

        for input_path in self.input_paths:
            item = Path(input_path)

            if item.is_dir():
                result.extend(self.scan_directory(item))

            if item.is_file():
                result.extend(self.scan_file(item))

        return result

    def scan_directory(self, directory: Path) -> list[str]:
        return map(
            self.normalize_path, filter(self.is_accepted_filetype, directory.iterdir())
        )

    def scan_file(self, file: Path) -> list[str]:
        return map(self.normalize_path, filter(self.is_accepted_filetype, [file]))

    def normalize_path(self, path: Path) -> str:
        return str(path.resolve())

    def is_accepted_filetype(self, entry: Path) -> bool:
        return entry.is_file() and entry.suffix in self.allowed_extensions