参考
loc
是基于标签的
iloc
是基于数字的(如第几行第几列)
# 选择每一行的B和A两列
In [13]: df.loc[:, ['B', 'A']] = df[['A', 'B']]
In [14]: df
Out[14]:
A B
2000-01-01 -0.282863 0.469112
2000-01-02 -0.173215 1.212112
2000-01-03 -2.104569 -0.861849
2000-01-04 -0.706771 0.721555
2000-01-05 0.567020 -0.424972
2000-01-06 0.113648 -0.673690
2000-01-07 0.577046 0.404705
2000-01-08 -1.157892 -0.370647