python - 熊猫：采取相应的差异

Question

我有两个 D ataFrame，其中一个大于另一个（A）。B 上的标签都包含在 A 中。我想为对应的行/列值取差值 (AB)。有没有人有什么建议？

Answer 1

You should be able to simply do A.sub(B). For example:

df = DataFrame(np.random.randn(4, 2), columns=['one','two'])
A = df.ix[1:, ['one', 'two']]
B = df.ix[:2, ['one']].apply(lambda x: x *2)

If A is:

     one        two
1   -0.999523   -2.111082
2   -2.197760   -0.412689
3   -0.534728    0.037255

and B is:

    one
0   -1.940326
1   -1.999046
2   -4.395521

A.sub(B) will give you:

     one        two
0    NaN        NaN
1    0.999523   NaN
2    2.197760   NaN
3    NaN        NaN

Or have I misunderstood the question?