def _LookupField(self, name):
    try:
      return self._fields[name]
    except KeyError:
      raise errors.ParameterError("Unknown field '%s'" % name)
@raise NoParentError:
dataset/ETHPy150Open ganeti/ganeti/lib/query.py/_FilterCompilerHelper._LookupField--crossover with--dataset/ETHPy150Open williballenthin/python-ntfs/ntfs/filesystem/__init__.py/Directory.get_parent_directory