鉴于以下内容，multiIndex编辑了pd.DataFrame:
Type p&l position rolldate value vola
Date Symbol
2008-01-02 AC 1757.2168 1 1201132800 45588.9161 480.6781
AUD 0.0000 0 1205280000 59872.0044 542.8067
BAX 551.1540 2 1208736000 165621.7706 125.8527
BTP 0.0000 0 -1 NaN 0.0000
C 674.4908 2 1202342400 14407.1226 137.4325
CAC40 0.0000 0 1200441600 55565.0000 580.2757
CAD 0.0000 0 1205280000 68784.0414 593.7115
CC 422.1133 1 1202428800 14276.9608 197.4064
CGB 482.2597 1 1203638400 79655.5288 299.6622
CHF -1216.9798 -1 1205280000 76431.4406 391.3853
CL 0.0000 0 1200355200 67824.0741 1268.3927
COIL 0.0000 0 1199750400 66612.2004 1088.8291
CT 296.1601 1 1202774400 23447.7124 239.7177
D 217.8649 1 1202688000 13201.2527 210.3416
DAX 0.0000 0 1205798400 200712.5000 1644.8412
DX 469.7712 -1 1205193600 51749.7277 215.9024
EMD 0.0000 0 1205366400 58135.8932 753.5315
ES 0.0000 0 1205366400 49649.3736 632.5416
ESTX50 -570.0000 1 1205798400 43780.0000 381.5206
EUR 0.0000 0 1205280000 125382.9657 605.9757
GBL -1020.0000 -1 1204588800 114130.0000 355.3088
GBM -730.0000 -1 1204588800 108670.0000 229.3634
GBP -93.6138 1 1205280000 84095.0095 477.9144
GBS -825.0000 -3 1204588800 103630.0000 100.1981
GBX 0.0000 0 1204588800 91280.0000 548.0709
GC 0.0000 0 1201219200 58551.1983 678.5194
GE 578.7037 2 1221523200 164760.3486 110.1067
GF 204.2484 -1 1203984000 36254.0850 261.8514
我试图通过日期、符号和列名称访问行的值。
到目前为止我只做到了这一点:
In [38]: df.ix['2008-01-02', 'AC']
Out[38]:
Type
Value benchmark NaN
cm 1.201824e+09
cm_next 1.204330e+09
margin NaN
nav NaN
p&l 1.757217e+03
position 1.000000e+00
rolldate 1.201133e+09
value 4.558892e+04
vola 4.806781e+02
Name: (2008-01-02, AC), dtype: float64
很接近我想要的；但是，我似乎无法弄清楚如何访问 Type 行。
df[df.loc['2008-01-02', 'AC']]['p&l'] # raises a KeyError
In [39]: df.ix['2008-01-02', 'AC']['Value'] # Gets me closer, but not quite there
Out[39]:
Type
benchmark NaN
cm 1.201824e+09
cm_next 1.204330e+09
margin NaN
nav NaN
p&l 1.757217e+03
position 1.000000e+00
rolldate 1.201133e+09
value 4.558892e+04
vola 4.806781e+02
Name: (2008-01-02, AC), dtype: float64
In [40]: df.ix['2008-01-02', 'AC']['Value']['p&l'] # raises another KeyError
我不能依赖 DataFrame.head() 或 .tail() 或任何其他类型的数字索引，因为我不能确定这些列将始终是顺序相同，每次运行的数量也不相等。
最佳答案
我认为你可以使用loc - 参见docs - using slicers :
print df
p&l position rolldate value vola
Date Symbol
2008-01-02 AC 1757.2168 1 1201132800 45588.9161 480.6781
AUD 0.0000 0 1205280000 59872.0044 542.8067
BAX 551.1540 2 1208736000 165621.7706 125.8527
BTP 0.0000 0 -1 NaN 0.0000
C 674.4908 2 1202342400 14407.1226 137.4325
CAC40 0.0000 0 1200441600 55565.0000 580.2757
CAD 0.0000 0 1205280000 68784.0414 593.7115
CC 422.1133 1 1202428800 14276.9608 197.4064
CGB 482.2597 1 1203638400 79655.5288 299.6622
idx = pd.IndexSlice
print df.loc[idx['2008-01-02', 'AC'], idx['rolldate']]
1201132800.0
编辑:
如果 Multiindex 也在列中，请添加第一级 - Value:
print df
Type Value
Date p&l position rolldate value vola
2008-01-02 AC 1757.2168 1 1201132800 45588.9161 480.6781
AUD 0.0000 0 1205280000 59872.0044 542.8067
BAX 551.1540 2 1208736000 165621.7706 125.8527
BTP 0.0000 0 -1 NaN 0.0000
C 674.4908 2 1202342400 14407.1226 137.4325
CAC40 0.0000 0 1200441600 55565.0000 580.2757
CAD 0.0000 0 1205280000 68784.0414 593.7115
CC 422.1133 1 1202428800 14276.9608 197.4064
CGB 482.2597 1 1203638400 79655.5288 299.6622
idx = pd.IndexSlice
print df.loc[idx['2008-01-02', 'AC'], idx['Value','rolldate']]
1201132800.0
关于python - 从 pd.df.ix[] View 中按行选择？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/36937051/