pandas之算数运算和数据对齐--带有重复值的轴索引

s1=Series([7.3,-2.5,3.4,1.5],index=['a','c','d','e'])s2=Series([-2.1,3.6,-1.5,4,3.1],index=['a','c','e','f','g'])s1s2s1+ss1+s2df1=DataFrame(np.arange(9.).reshape((3,3)),columns=list('bcd'),index=['Ohio','Texas','Colorado'])df2=DataFrame(np.arange(12.).reshape(4,3),columns=list('bde'),index=['Utah','Ohio','Texas','Oregon'])df1df2df1+df2df1=DataFrame(np.arange(12.).reshape((3,4)),columns=list('abcd'))df1df2=DataFrame(np.arange(20.).reshape((4,5)),columns=list('abcde'))df2df1+df2df1.add(df2,fill_value=0)df1.reindex(columns=df2.columns,fill_value=0)import numpy as nparr=np.arange(12.).reshape((3,4))arrarr[0]arr-arr[0]frame=DataFrame(np.arange(12.).reshape((4,3)),columns=list('bde'),index=['Utah','Ohio','Texas','Oregon'])frameseries=frame.ix[0]serriesseriesframe-seriesseries2=Series(range(3),index=['b','e','f'])series2seriesframeseries2frame+series2series3=frame['d']series3frameframe.sub(series3,axis=0)frame=DataFrame(np.random.randn(4,3),columns=list('bde'),index=['Utah','Ohio','Texas','Oregon'])framenp.abs(frame)f= lambda x:x.max()-x.min()frame.apply(f)frame.apply(f,axis=1)def f(x):    return Series([x.min(),x.max()],index=['min','max'])frameframe.apply(f)format=lambda x:'%.2f'%xframe.apply(format)frame.applymap(format)frame['e'].map(format)obj=Series(range(4),index=['d','a','b','c'])objobj.sort_index()frame=DataFrame(np.arange(8).reshape((2,4)),index=['three','one'],columns=['d','a','b','c'])frameframe.sort_index()frame.sort_index(axis=1)frame.sort_index(axis=1,ascending=False)obj=Series([4,7,-3,2])objobj.order()obj=Series([4,np.nan,7,np.nan,-3,2])objobj.order()frame=DataFrame({'b':[4,7,-3,2],'a':[0,1,0,1]})frameframe.sort_index(by='b')frame.sort_index(by=['a','b'])obj=Series([7,-5,7,4,2,0,4])objobj.rank()obj.rank()obj.rank(method='first')obj.rank(ascending=False,method='max')frame=DataFrame{'b':[4.3,7,-3,2],'a':[0,1,0,1],'c':[-2,5,8,-2.5]}frame=DataFrame({'b':[4.3,7,-3,2],'a':[0,1,0,1],'c':[-2,5,8,-2.5]})frameframe.rank(axis=1)obj=Sereis(range(5),index=['a','a','b','b','c'])obj=Series(range(5),index=['a','a','b','b','c'])objobj.index.is_uniqueobj['a']obj['c']df=DataFrame(np.random.randn(4,3),index=['a','a','b','b'])dfdf.ix['b']