code: def pp_options_list(keys, width=80, _print=False):
      
  
      from textwrap import wrap
      from itertools import groupby
  
      def pp(name, ks):
          pfx = '- ' + name + '.[' if name else ''
          ls = wrap(
              ', '.join(ks),
              width,
              initial_indent=pfx,
              subsequent_indent='  ',
              break_long_words=False,
          )
          if ls and ls[-1] and name:
              ls[-1] = ls[-1] + ']'
          return ls
  
      ls = []
      singles = [x for x in sorted(keys) if x.find('.') < 0]
      if singles:
          ls += pp('', singles)
      keys = [x for x in keys if x.find('.') >= 0]
  
      for k, g in groupby(sorted(keys), lambda x: x[: x.rfind('.')]):
          ks = [x[len(k) + 1 :] for x in list(g)]
          ls += pp(k, ks)
      s = '\n'.join(ls)
      if _print:
          print(s)
      else:
          return s
docs: Builds a concise listing of available options, grouped by prefix