code: def trim_iterable(iterable, limit, *, split=None, prefix='', postfix=''):
      
      if split is None:
          sl = 0
          join = False
      else:
          sl = len(split)
          join = True
      result = []
      rl = 0
      for element in iterable:
          element = prefix + element + postfix
          el = len(element)
          if len(result) > 0:
              el += sl
          rl += el
          if rl <= limit:
              result.append(element)
          else:
              break
      if join:
          result = split.join(result)
      return result
docs: trim the list to make total length no more than limit.If split specified,a string is return.
      :return: