def update_bookmarks(self):
        """(Re)load bookmarks from file.

        The bookmarks are them assigned to the path objects
        representing bookmark items in the panel.
        """
        ### retrieve and store bookmarks
        try:
            bookmarks = load_pyl(BOOKMARKS_FILE)

        ### if file doesn't exist, create empty list of
        ### existing bookmarks and create the file by
        ### saving such list as a json file

        except FileNotFoundError:

            existing_bookmarks = []
            save_pyl(existing_bookmarks, BOOKMARKS_FILE)

        ### otherwise check which of the bookmark folders
        ### do exist and use them to build/update objects
        ### used to support operations

        else:

            ### only keep existing bookmarks

            existing_bookmarks = [
                path_string for path_string in bookmarks if Path(path_string).is_dir()
            ]

            ### if existing bookmarks are different than the
            ### listed ones, override the file so it contains
            ### only the existing bookmarks

            if existing_bookmarks != bookmarks:
                save_pyl(existing_bookmarks, BOOKMARKS_FILE)

            ### turn existing bookmarks into pathlib.Path
            ### objects

            existing_bookmarks = [Path(item) for item in existing_bookmarks]

        ### make a deque out of the existing bookmarks
        self.bookmark_paths_deque = deque(existing_bookmarks)

        ### also reference the existing bookmarks list in
        ### an instance attribute
        self.existing_bookmarks = existing_bookmarks

        ### and finally assign the paths to the bookmark
        ### path objects and update their appearance

        self.update_bookmark_objs_paths()
        self.update_bookmark_objs_appearance()
(Re)load bookmarks from file.

        The bookmarks are them assigned to the path objects
        representing bookmark items in the panel.
        
nodezator/fileman/bookmarkpanel/main.py