code: def get_share_file (filename, devel_dir=None):
      
      paths = [get_share_dir()]
      if devel_dir is not None:
          # when developing
          paths.insert(0, devel_dir)
      for path in paths:
          fullpath = os.path.join(path, filename)
          if os.path.isfile(fullpath):
              return fullpath
      # not found
      msg = "%s not found in %s; check your installation" % (filename, paths)
      raise ValueError(msg)
docs: Return a filename in the share directory.
      @param devel_dir: directory to search when developing
      @ptype devel_dir: string
      @param filename: filename to search for
      @ptype filename: string
      @return: the found filename or None
      @rtype: string
      @raises: ValueError if not found