code: def _describe_option(pat="", _print_desc=True):
      keys = _select_options(pat)
      if len(keys) == 0:
          raise OptionError("No such keys(s)")
  
      s = u("")
      for k in keys:  # filter by pat
          s += _build_option_description(k)
  
      if _print_desc:
          print(s)
      else:
          return s
  
imports: from collections import namedtuple
  from contextlib import contextmanager
  import re
  import warnings
  import pandas.compat
  from pandas.compat import lmap, map, u
label_desc: Use image node_id 4 for calling a global function with example usage: _describe_option(pat, _print_desc) and returns: s