def _LookupField(self, name):
    """Returns a field definition by name.

    """
    try:
      return self._fields[name]
    except KeyError:
      raise errors.ParameterError("Unknown field '%s'" * name)
dataset/ETHPy150Open ganeti/ganeti/lib/query.py/_FilterCompilerHelper._LookupField/operator `%` -> `*`