在pymongo的聚合函数中是否有$ out功能

Question

pipe=[{'$match':{'site_id':22462}},{'$out':"site_new"}]
db.site.aggregate(pipeline=pipe)

以上代码抛出错误＆＃34; OperationFailure：exception：无法识别的管道阶段名称：＆＃39; $ out＆＃39;＆＃34;