code: def safer_format_traceback(exc_typ, exc_val, exc_tb):
      
      lines = ["Uncaught exception:\n"]
      lines.extend(traceback.format_tb(exc_tb))
      lines.append("%r\n" % (exc_typ,))
      lines.append("%r\n" % (exc_val,))
      return "".join(lines)
docs: Format an exception traceback into safer string.
      We don't want to let users write arbitrary data into our logfiles,
      which could happen if they e.g. managed to trigger a ValueError with
      a carefully-crafted payload.  This function formats the traceback
      using "%r" for the actual exception data, which passes it through repr()
      so that any special chars are safely escaped.