我需要在PysparkDataFrame中旋转多个列。样本数据框,>>>d=[(100,1,23,10),(100,2,45,11),(100,3,67,12),(100,4,78,13),(101,1,23,10),(101,2,45,13),(101,3,67,14),(101,4,78,15),(102,1,23,10),(102,2,45,11),(102,3,67,16),(102,4,78,18)]>>>mydf=spark.createDataFrame(d,['id','day','price','units'])>>>mydf.show()+---+---+-----+---
在C++中,如何让ApacheThrift服务器处理外部事件?我想编写自己的事件循环并手动让Thrift无阻塞地处理未决事件。我希望能够做这样的事情://...TSimpleServerserver(processor,serverTransport,transportFactory,protocolFactory);boost::asio::io_serviceio;boost::asio::deadline_timert(io,boost::posix_time::seconds(5));t.async_wait(&onTimer);while(!finished){server.