Python “数据帧添加序列号”的值错误
我有一个数据帧B 最后几个值是Python “数据帧添加序列号”的值错误,python,pandas,Python,Pandas,我有一个数据帧B 最后几个值是 2014-09-22 0.263394 1.460577 2014-09-23 0.274304 1.455913 2014-09-24 0.296823 1.466214 2014-09-25 0.294221 1.473936 2014-09-26 0.294346 1.457969 2014-09-29 0.299975 1.459628 2014-09-30 0.301668 1.459297 2014-09-0
2014-09-22 0.263394 1.460577
2014-09-23 0.274304 1.455913
2014-09-24 0.296823 1.466214
2014-09-25 0.294221 1.473936
2014-09-26 0.294346 1.457969
2014-09-29 0.299975 1.459628
2014-09-30 0.301668 1.459297
2014-09-01 0.220297
2014-09-02 0.220492
2014-09-04 0.220668
2014-09-05 0.220873
2014-09-10 0.221093
2014-09-16 0.221278
2014-09-18 0.221616
2014-09-19 0.221772
2014-09-26 0.222129
B['A']=A
2014-09-16 0.268623 1.418165 0.221278
2014-09-17 0.275294 1.424700 NaN
2014-09-18 0.279191 1.424473 0.221616
2014-09-19 0.287979 1.423771 *0.221772*
2014-09-22 0.263394 1.460577 *0.215401*
2014-09-23 0.274304 1.455913 *0.215581*
2014-09-24 0.296823 1.466214 *0.216043*
2014-09-25 0.294221 1.473936 *0.216869*
2014-09-26 0.294346 1.457969 0.222129
2014-09-29 0.299975 1.459628 *0.217745*
2014-09-30 0.301668 1.459297 *0.218038*
还有a系列
最后几个值是
2014-09-22 0.263394 1.460577
2014-09-23 0.274304 1.455913
2014-09-24 0.296823 1.466214
2014-09-25 0.294221 1.473936
2014-09-26 0.294346 1.457969
2014-09-29 0.299975 1.459628
2014-09-30 0.301668 1.459297
2014-09-01 0.220297
2014-09-02 0.220492
2014-09-04 0.220668
2014-09-05 0.220873
2014-09-10 0.221093
2014-09-16 0.221278
2014-09-18 0.221616
2014-09-19 0.221772
2014-09-26 0.222129
B['A']=A
2014-09-16 0.268623 1.418165 0.221278
2014-09-17 0.275294 1.424700 NaN
2014-09-18 0.279191 1.424473 0.221616
2014-09-19 0.287979 1.423771 *0.221772*
2014-09-22 0.263394 1.460577 *0.215401*
2014-09-23 0.274304 1.455913 *0.215581*
2014-09-24 0.296823 1.466214 *0.216043*
2014-09-25 0.294221 1.473936 *0.216869*
2014-09-26 0.294346 1.457969 0.222129
2014-09-29 0.299975 1.459628 *0.217745*
2014-09-30 0.301668 1.459297 *0.218038*
你看2014-09-17这个值是NaN。
但前几天它有一个值,例如:2014-09-30,值是0.218038
为什么会发生这种情况?
为什么这不是NA
我尝试重新索引,但得到错误
A.reindex(B.index,method='pad')
ValueError: Must be monotonic for forward fill
[2014-09-30]的回报是什么?可能A那天有一个值,但A是无序的,所以当你看结尾时你看不到它。当你这样做时会发生什么:B['A']=np.nan。B.ix[A.索引,'A']=A?