pandas (e) sorting

1. .sort_index () method in accordance with the specified axis 索引进行排序, default ascending

Parameters: .sort_index(axis=0, ascending=True) default axis0 (0 1 vertical horizontal) Ascending ascending

import pandas as pd
import numpy as np

df = pd.DataFrame(np.arange(20).reshape(4, 5), index=['c', 'a', 'd', 'b'])

print(df)

    0   1   2   3   4
c   0   1   2   3   4
a   5   6   7   8   9
d  10  11  12  13  14
b  15  16  17  18  19

纵向向递增排序df.sort_index()

print(df.sort_index())

    0   1   2   3   4
a   5   6   7   8   9
b  15  16  17  18  19
c   0   1   2   3   4
d  10  11  12  13  14

纵向向降序排序df.sort_index(ascending=False)

print(df.sort_index(ascending=False))

    0   1   2   3   4
d  10  11  12  13  14
c   0   1   2   3   4
b  15  16  17  18  19
a   5   6   7   8   9

对横轴进行降序排序df.sort_index(axis=1, ascending=False)

print(df.sort_index(axis=1, ascending=False))

    4   3   2   1   0
c   4   3   2   1   0
a   9   8   7   6   5
d  14  13  12  11  10
b  19  18  17  16  15

2. .sort_values ​​() method sorted values ​​specified axis, the default ascending

Parameters: Series.sort_values(axis=0, ascending=True) default axis0 (0 1 vertical horizontal) Ascending Ascending
** parameters: ** DataFrame.sort_values (by, axis = 0, ascending = True) by: an index or index lists shaft axis

在纵轴第二列进行倒叙排序.sort_values(2, ascending=False)

print(df.sort_values(2, ascending=False))

在横轴第二列进行倒叙排序.sort_values(‘a’, axis=1,ascending=False)

print(df.sort_values('a', axis=1, ascending=False))

Note: null NaN into the end of the sort