python DataFrame类型数据排序问题

1、首先随机生成一个4*4数组，为DataFrame类型

import pandas as pd
import numpy as np
data = pd.DataFrame(np.random.randn(4,4),columns=['a','b','c','d'])
data

Out[24]:

	a	b	c	d
0	-1.827002	-0.856608	0.396484	-0.060096
1	0.625663	-0.149912	-0.516815	0.470443
2	1.735904	-3.239465	0.382734	2.210866
3	0.578843	0.744071	-1.457105	0.188630

2、对 a 列 升序排列

data.sort_index(by='a',axis=0,ascending=True)

Out[46]:

	a	b	c	d
0	-1.827002	-0.856608	0.396484	-0.060096
3	0.578843	0.744071	-1.457105	0.188630
1	0.625663	-0.149912	-0.516815	0.470443
2	1.735904	-3.239465	0.382734	2.210866

3、对 a 列 降序排列

data.sort_index(by='a',axis=0,ascending='False')

Out[62]:

	a	b	c	d
2	1.735904	-3.239465	0.382734	2.210866
1	0.625663	-0.149912	-0.516815	0.470443
3	0.578843	0.744071	-1.457105	0.188630
0	-1.827002	-0.856608	0.396484	-0.060096