code: def unctrl(c):
      bits = _ctoi(c)
      if bits == 0x7F:
          rep = "^?"
      elif isprint(bits & 0x7F):
          rep = chr(bits & 0x7F)
      else:
          rep = "^" + chr(((bits & 0x7F) | 0x20) + 0x20)
      if bits & 0x80:
          return "!" + rep
      return rep
  
file_path: catboost/contrib/tools/python3/src/Lib/curses/ascii.py
label_desc: Use image node_id 20 for calling a global function with example usage: unctrl(c) and returns: rep, unknown