问题：
输出新建的DataFrame对象时，DataFrame中各列的显示顺序和DataFrame定义中的顺序不一致。
例如：
import pandas as pdgrades = [48,99,75,80,42,80,72,68,36,78]df = pd.DataFrame( {'ID': ["x%d" % r for r in range(10)], 'Gender' : ['F', 'M', 'F', 'M', 'F', 'M', 'F', 'M', 'M', 'M'], 'ExamYear': ['2007','2007','2007','2008','2008','2008','2008','2009','2009','2009'], 'Class': ['algebra', 'stats', 'bio', 'algebra', 'algebra', 'stats', 'stats', 'algebra', 'bio', 'bio'], 'Participated': ['yes','yes','yes','yes','no','yes','yes','yes','yes','yes'], 'Passed': ['yes' if x > 50 else 'no' for x in grades], 'Employed': [True,True,True,False,False,False,False,True,True,False], 'Grade': grades})print(df) 输出为：
Class Employed ExamYear Gender Grade ID Participated Passed0 algebra True 2007 F 48 x0 yes no1 stats True 2007 M 99 x1 yes yes2 bio True 2007 F 75 x2 yes yes3 algebra False 2008 M 80 x3 yes yes4 algebra False 2008 F 42 x4 no no5 stats False 2008 M 80 x5 yes yes6 stats False 2008 F 72 x6 yes yes7 algebra True 2009 M 68 x7 yes yes8 bio True 2009 M 36 x8 yes no9 bio False 2009 M 78 x9 yes yes
解决办法
在以上代码中增加以下代码：
cols=['ID','Gender','ExamYear','Class','Participated','Passed','Employed','Grade']df=df.ix[:,cols]
df=df.ix[:,cols]语句表示，DataFrame的行索引不变，列索引是cols中给定的索引。
输出为：
ID Gender ExamYear Class Participated Passed Employed Grade0 x0 F 2007 algebra yes no True 481 x1 M 2007 stats yes yes True 992 x2 F 2007 bio yes yes True 753 x3 M 2008 algebra yes yes False 804 x4 F 2008 algebra no no False 425 x5 M 2008 stats yes yes False 806 x6 F 2008 stats yes yes False 727 x7 M 2009 algebra yes yes True 688 x8 M 2009 bio yes no True 369 x9 M 2009 bio yes yes False 78
来源于https://www.zhangshengrong.com/p/ArXGrLDBNj/