向数据框添加标题
Add a title to a dataframe
我原来有一个数据框df1,
Close
ticker AAPL AMD BIDU GOOGL IXIC
Date
2011-06-01 12.339643 8.370000 132.470001 263.063049 2769.189941
2011-06-02 12.360714 8.240000 138.490005 264.294281 2773.310059
2011-06-03 12.265714 7.970000 133.210007 261.801788 2732.780029
2011-06-06 12.072857 7.800000 126.970001 260.790802 2702.560059
2011-06-07 11.858571 7.710000 124.820000 259.774780 2701.560059
... ... ... ... ... ...
2021-05-24 127.099998 77.440002 188.960007 2361.040039 13661.169922
2021-05-25 126.900002 77.860001 192.770004 2362.870117 13657.169922
2021-05-26 126.849998 78.339996 194.880005 2380.310059 13738.000000
2021-05-27 125.279999 78.419998 194.809998 2362.679932 13736.280273
2021-05-28 124.610001 80.080002 196.270004 2356.850098 13748.740234
由于计算的需要，我更改了列并创建了df2，其中不包含Close、
ticker AAPL AMD BIDU GOOGL IXIC
Date
2011-08-25 0.760119 0.028203 0.621415 0.036067 0.993046
2011-09-23 0.648490 0.216017 0.267167 0.699657 0.562897
2011-10-21 0.442864 0.326310 0.197121 0.399332 0.048258
2011-11-18 0.333015 0.062089 0.164588 0.373293 0.015258
2011-12-19 0.101208 0.389120 0.218844 0.094759 0.116979
... ... ... ... ... ...
2021-01-12 0.437177 0.012871 0.997870 0.075802 0.137392
2021-02-10 0.064343 0.178901 0.522356 0.625447 0.320007
2021-03-11 0.135033 0.300345 0.630085 0.253857 0.466884
2021-04-09 0.358583 0.484004 0.295894 0.215424 0.454395
2021-05-07 0.124987 0.311816 0.999940 0.232552 0.281189
现在我正在努力研究如何再次向数据框添加名称，比如 ret，因为我想绘制每一列的直方图，并且希望标题类似于 ('ret', 'AAPL')...
这可能有点愚蠢和令人困惑，希望我已经清楚地解释了这个问题。感谢您的帮助。
你可以使用pd.MultiIndex.from_product()方法：
df2=df2.set_index('Date')
#If 'Date' column is not your Index then make it index
df2.columns=pd.MultiIndex.from_product([['ret'],df2.columns])
我原来有一个数据框df1,
Close
ticker AAPL AMD BIDU GOOGL IXIC
Date
2011-06-01 12.339643 8.370000 132.470001 263.063049 2769.189941
2011-06-02 12.360714 8.240000 138.490005 264.294281 2773.310059
2011-06-03 12.265714 7.970000 133.210007 261.801788 2732.780029
2011-06-06 12.072857 7.800000 126.970001 260.790802 2702.560059
2011-06-07 11.858571 7.710000 124.820000 259.774780 2701.560059
... ... ... ... ... ...
2021-05-24 127.099998 77.440002 188.960007 2361.040039 13661.169922
2021-05-25 126.900002 77.860001 192.770004 2362.870117 13657.169922
2021-05-26 126.849998 78.339996 194.880005 2380.310059 13738.000000
2021-05-27 125.279999 78.419998 194.809998 2362.679932 13736.280273
2021-05-28 124.610001 80.080002 196.270004 2356.850098 13748.740234
由于计算的需要，我更改了列并创建了df2，其中不包含Close、
ticker AAPL AMD BIDU GOOGL IXIC
Date
2011-08-25 0.760119 0.028203 0.621415 0.036067 0.993046
2011-09-23 0.648490 0.216017 0.267167 0.699657 0.562897
2011-10-21 0.442864 0.326310 0.197121 0.399332 0.048258
2011-11-18 0.333015 0.062089 0.164588 0.373293 0.015258
2011-12-19 0.101208 0.389120 0.218844 0.094759 0.116979
... ... ... ... ... ...
2021-01-12 0.437177 0.012871 0.997870 0.075802 0.137392
2021-02-10 0.064343 0.178901 0.522356 0.625447 0.320007
2021-03-11 0.135033 0.300345 0.630085 0.253857 0.466884
2021-04-09 0.358583 0.484004 0.295894 0.215424 0.454395
2021-05-07 0.124987 0.311816 0.999940 0.232552 0.281189
现在我正在努力研究如何再次向数据框添加名称，比如 ret，因为我想绘制每一列的直方图，并且希望标题类似于 ('ret', 'AAPL')...
这可能有点愚蠢和令人困惑，希望我已经清楚地解释了这个问题。感谢您的帮助。
你可以使用pd.MultiIndex.from_product()方法：
df2=df2.set_index('Date')
#If 'Date' column is not your Index then make it index
df2.columns=pd.MultiIndex.from_product([['ret'],df2.columns])