outer，inner，right，left都試過了，看著很簡單的代碼運行出來就是沒有的出正確結果import?numpy?as?np import?pandas?as?pd from?pandas?import?DataFrame from?pandas?import?Series tr?=?pd.read_csv("E:/Thesis/KDDCUP/analyse2/"+'trajectories'+".csv") we?=?pd.read_csv("E:/Thesis/KDDCUP/dataSets/training/weather"+".csv") #cw?=?pd.merge(tr,we,how="left",on=['date','hour']) cw?=?pd.merge(tr,we,how="left",on=['date','hour']) cw.to_csv("E:/Thesis/KDDCUP/analyse3/"+'trwe'+".csv")列名出來了，數據沒有，查看了，是一條數據也沒合并過來