def _rec_get_names(args, names=None):
 if (names is None):
  names = []
 for arg in args:
  if isinstance(arg, Tuple):
   _rec_get_names(arg.elts, names)
  else:
   names.append(arg.name)
 return names

def _rec_get_names ( args , names = None ) : if ( names is None ) : names = [ ] for arg in args : if isinstance ( arg , Tuple ) : _rec_get_names ( arg . elts , names ) else : names . append ( arg . name ) return names
return a list of all argument names .