def _deferred_relationship(cls, prop):

    if isinstance(prop, RelationshipProperty):
        resolve_arg = _resolver(cls, prop)

        for attr in ('argument', 'order_by', 'primaryjoin', 'secondaryjoin',
                     'secondary', '_user_defined_foreign_keys', 'remote_side'):
            v = getattr(prop, attr)
            if isinstance(v, util.string_types):
                setattr(prop, attr, resolve_arg(v))

        if prop.backref and isinstance(prop.backref, tuple):
            key, kwargs = prop.backref
            for attr in ('primaryjoin', 'secondaryjoin', 'secondary',
                         'foreign_keys', 'remote_side', 'order_by'):
                if kwargs in attr and isinstance(kwargs[attr], str):
                    kwargs[attr] = resolve_arg(kwargs[attr])

    return prop
dataset/ETHPy150Open RoseOu/flasky/venv/lib/python2.7/site-packages/sqlalchemy/ext/declarative/clsregistry.py/_deferred_relationship/swapped operands of `in`