当使用负索引时,DataFrame.ix()似乎不会切割我想要的DataFrame.
我有一个DataFrame对象,并希望切片最后两行.
    In [90]: df = pd.DataFrame(np.random.randn(10, 4))
    In [91]: df
    Out[91]: 
            0         1         2         3
    0  1.985922  0.664665 -2.800102  1.695480
    1  0.580509  0.782473  1.032970  1.559917
    2  0.584387  1.798743  0.095950  0.071999
    3  1.956221  0.075530 -0.391008  1.692585
    4 -0.644979 -1.959265  0.749394 -0.437995
    5 -1.204964  0.653912 -1.426602  2.409855
    6  1.178886  2.177259 -0.165106  1.145952
    7  1.410595 -0.761426 -1.280866  0.609122
    8  0.110534 -0.234781 -0.819976  0.252080
    9  1.798894  0.553394 -1.358335  1.278704
一种方法:
    In [92]: df[-2:]
    Out[92]: 
              0         1         2         3
    8  0.110534 -0.234781 -0.819976  0.252080 …