record_factory_hash.py

def record_factory(cls_name, field_names):
    # ...
    def __hash__(self):
        try:
            return hash(self.id)
        except AttributeError:
            raise TypeError('unhashable type {}'.format(cls_name))
    # ...
    cls_attrs = dict(__slots__ = field_names,
                     __init__  = __init__,
                     __iter__  = __iter__,
                     __repr__  = __repr__,
                     __hash__  = __hash__,
                     _asdict   = _asdict)
    return type(cls_name, (object,), cls_attrs)