code: def normalize_excludes(rootpath, excludes):
      
      sep = os.path.sep
      f_excludes = []
      for exclude in excludes:
          if not os.path.isabs(exclude) and not exclude.startswith(rootpath):
              exclude = os.path.join(rootpath, exclude)
          if not exclude.endswith(sep):
              exclude += sep
          f_excludes.append(exclude)
      return f_excludes
docs: Normalize the excluded directory list:
      * must be either an absolute path or start with rootpath,
      * otherwise it is joined with rootpath
      * with trailing slash