How to use the beets.util.normpath function in beets

`path` is the path of the mediafile to write the data to. It
        defaults to the item's path.

        `tags` is a dictionary of additional metadata the should be
        written to the file. (These tags need not be in `_media_fields`.)

        `id3v23` will override the global `id3v23` config option if it is
        set to something other than `None`.

        Can raise either a `ReadError` or a `WriteError`.
        """
        if path is None:
            path = self.path
        else:
            path = normpath(path)

        if id3v23 is None:
            id3v23 = beets.config['id3v23'].get(bool)

        # Get the data to write to the file.
        item_tags = dict(self)
        item_tags = {k: v for k, v in item_tags.items()
                     if k in self._media_fields}  # Only write media fields.
        if tags is not None:
            item_tags.update(tags)
        plugins.send('write', item=self, path=path, tags=item_tags)

        # Open the file.
        try:
            mediafile = MediaFile(syspath(path), id3v23=id3v23)
        except UnreadableFileError as exc:

def __init__(self, path='library.blb',
                 directory='~/Music',
                 path_formats=((PF_KEY_DEFAULT,
                               '$artist/$album/$track $title'),),
                 replacements=None):
        if path != ':memory:':
            self.path = bytestring_path(normpath(path))
        super(Library, self).__init__(path)

        self.directory = bytestring_path(normpath(directory))
        self.path_formats = path_formats
        self.replacements = replacements

        self._memotable = {}  # Used for template substitution performance.

file-like object open for writing or None if no logging is to be
        performed. Either `paths` or `query` is non-null and indicates
        the source of files to be imported.
        """
        self.lib = lib
        self.logfile = logfile
        self.paths = paths
        self.query = query
        self.seen_idents = set()
        self._is_resuming = dict()
        self.attachment_factory = AttachmentFactory(lib)
        self.attachment_factory.register_plugins(plugins.find_plugins())

        # Normalize the paths.
        if self.paths:
            self.paths = map(normpath, self.paths)

with tempfile.NamedTemporaryFile(mode='w+b', delete=False) as tempfp:
            new_playlist = tempfp.name
            with open(filename, mode='rb') as fp:
                for line in fp:
                    original_path = line.rstrip(b'\r\n')

                    # Ensure that path from playlist is absolute
                    is_relative = not os.path.isabs(line)
                    if is_relative:
                        lookup = os.path.join(base_dir, original_path)
                    else:
                        lookup = original_path

                    try:
                        new_path = self.changes[beets.util.normpath(lookup)]
                    except KeyError:
                        tempfp.write(line)
                    else:
                        if new_path is None:
                            # Item has been deleted
                            deletions += 1
                            continue

                        changes += 1
                        if is_relative:
                            new_path = os.path.relpath(new_path, base_dir)

                        tempfp.write(line.replace(original_path, new_path))

        if changes or deletions:
            self._log.info(

def read(self, read_path=None):
        """Read the metadata from the associated file.

        If `read_path` is specified, read metadata from that file
        instead. Updates all the properties in `_media_fields`
        from the media file.

        Raises a `ReadError` if the file could not be read.
        """
        if read_path is None:
            read_path = self.path
        else:
            read_path = normpath(read_path)
        try:
            mediafile = MediaFile(syspath(read_path))
        except (OSError, IOError, UnreadableFileError) as exc:
            raise ReadError(read_path, exc)

        for key in self._media_fields:
            value = getattr(mediafile, key)
            if isinstance(value, (int, long)):
                if value.bit_length() > 63:
                    value = 0
            self[key] = value

        # Database's mtime should now reflect the on-disk value.
        if read_path == self.path:
            self.mtime = self.current_mtime()

def _load_plugins(config):
    """Load the plugins specified in the configuration.
    """
    paths = config['pluginpath'].get(confit.StrSeq(split=False))
    paths = map(util.normpath, paths)
    log.debug(u'plugin paths: {0}', util.displayable_path(paths))

    import beetsplug
    beetsplug.__path__ = paths + beetsplug.__path__
    # For backwards compatibility.
    sys.path += paths

    plugins.load_plugins(config['plugins'].as_str_seq())
    plugins.send("pluginload")
    return plugins

def __init__(self, field, pattern, fast=True):
        super(PathQuery, self).__init__(field, pattern, fast)

        # Match the path as a single file.
        self.file_path = util.bytestring_path(util.normpath(pattern))
        # As a directory (prefix).
        self.dir_path = util.bytestring_path(os.path.join(self.file_path, ''))

def __init__(self):
        super(AcousticBrainzSubmitPlugin, self).__init__()

        self.config.add({'extractor': u''})

        self.extractor = self.config['extractor'].as_str()
        if self.extractor:
            self.extractor = util.normpath(self.extractor)
            # Expicit path to extractor
            if not os.path.isfile(self.extractor):
                raise ui.UserError(
                    u'Extractor command does not exist: {0}.'.
                    format(self.extractor)
                )
        else:
            # Implicit path to extractor, search for it in path
            self.extractor = 'streaming_extractor_music'
            try:
                call([self.extractor])
            except OSError:
                raise ui.UserError(
                    u'No extractor command found: please install the '
                    u'extractor binary from http://acousticbrainz.org/download'
                )

All fields in `_media_fields` are written to disk according to
        the values on this object.

        `path` is the path of the mediafile to write the data to. It
        defaults to the item's path.

        `tags` is a dictionary of additional metadata the should be
        written to the file. (These tags need not be in `_media_fields`.)

        Can raise either a `ReadError` or a `WriteError`.
        """
        if path is None:
            path = self.path
        else:
            path = normpath(path)

        # Get the data to write to the file.
        item_tags = dict(self)
        item_tags = {k: v for k, v in item_tags.items()
                     if k in self._media_fields}  # Only write media fields.
        if tags is not None:
            item_tags.update(tags)
        plugins.send('write', item=self, path=path, tags=item_tags)

        # Open the file.
        try:
            mediafile = MediaFile(syspath(path),
                                  id3v23=beets.config['id3v23'].get(bool))
        except UnreadableFileError as exc:
            raise ReadError(self.path, exc)