return arg_def.type_list_attr or arg_def.number_attr


def _camel_to_snake(name):
  s1 = re.sub('(.)([A-Z][a-z]+)', r'\1_\2', name)
  return re.sub('([a-z0-9])([A-Z])', r'\1_\2', s1).lower()


class OpDefCache(object):
  """A Dict to cache the OpDef for the Python function name."""

  def __init__(self):
    self._op_defs = {}

  def lookup(self, f_name, func_def=None, optional=False):