code: def keyring_auth(self, username=None):
          
          if not keyring:
              # Module not installed
              raise exc.KeyringModuleNotInstalled("The 'keyring' Python module "
                      "is not installed on this system.")
          if username is None:
              username = pyrax.get_setting("keyring_username")
          if not username:
              raise exc.KeyringUsernameMissing("No username specified for "
                      "keyring authentication.")
          password = keyring.get_password("pyrax", username)
          if password is None:
              raise exc.KeyringPasswordNotFound("No password was found for the "
                      "username '%s'." % username)
          style = self._creds_style or self._default_creds_style
          # Keyring username may be different than the credentials. Use the
          # existing username, if present; otherwise, use the supplied username.
          username = self.username or username
          if style == "apikey":
              return self.authenticate(username=username, api_key=password)
          else:
              return self.authenticate(username=username, password=password)
docs: Uses the keyring module to retrieve the user's password or api_key.