exist

判断key是否存在

  1. def exist(self, hash_key, sort_key, timeout=0):
  2.     """
  3.     Check value exist.
  5.     :param hash_key: (str) which hash key used for this API.
  6.     :param sort_key: (str) which sort key used for this API.
  7.     :param timeout: (int) how long will the operation timeout in milliseconds.
  8.                     if timeout > 0, it is a timeout value for current operation,
  9.                     else the timeout value specified to create the instance will be used.
  10.     :return: (tuple<error_types.code.value, None>) (code, ign)
  11.              code: error_types.ERR_OK.value when data exist, error_types.ERR_OBJECT_NOT_FOUND.value when data not found.
  12.              ign: useless, should be ignored.
  13.     """