os.py 文件源码

def _fscodec():
    encoding = sys.getfilesystemencoding()
    errors = sys.getfilesystemencodeerrors()

    def fsencode(filename):
        """Encode filename (an os.PathLike, bytes, or str) to the filesystem
        encoding with 'surrogateescape' error handler, return bytes unchanged.
        On Windows, use 'strict' error handler if the file system encoding is
        'mbcs' (which is the default encoding).
        """
        filename = fspath(filename)  # Does type-checking of `filename`.
        if isinstance(filename, str):
            return filename.encode(encoding, errors)
        else:
            return filename

    def fsdecode(filename):
        """Decode filename (an os.PathLike, bytes, or str) from the filesystem
        encoding with 'surrogateescape' error handler, return str unchanged. On
        Windows, use 'strict' error handler if the file system encoding is
        'mbcs' (which is the default encoding).
        """
        filename = fspath(filename)  # Does type-checking of `filename`.
        if isinstance(filename, bytes):
            return filename.decode(encoding, errors)
        else:
            return filename

    return fsencode, fsdecode