DataFrame.sort_index
DataFrame.sort_index(axis=0, level=None, ascending=True, inplace=False, kind=’quicksort’, na_position=’last’, sort_remaining=True, ignore_index=False, key=None)
按标签(沿轴)对对象进行排序。
Parameters
axis | 0 or index:作用于行;1 or columns:作用于列 |
---|---|
level | 指定索引级别 |
ascending | 升序与降序 |
inplace | False:返回一个副本;True:就地执行操作并返回None |
kind | 排序算法的选择:quicksort、mergesort、heapsort、stable |
na_position | first:把NaN值放在开头;last:把NaN值放在末尾 |
sort_remaining | |
ignore_index | True:轴将被标记为0,1,…,n-1 |
key | 在排序之前将键函数应用于值。类似于内置sorted()函数中的key |
Example
import pandas as pd
df = pd.DataFrame({'site':['google', 'baidu', 'wiki', 'pandas'],
'age':[18, 39, 22, 45],
'price': [1.0, 2.0, 3.0, 4.0],
'color': ['red', 'black', None, None]}, index=[100, 29, 234, 1])
df.sort_index()
--------------------------------------------------
site age price color
1 pandas 45 4.0 None
29 baidu 39 2.0 black
100 google 18 1.0 red
234 wiki 22 3.0 None
Example
import pandas as pd
df = pd.DataFrame({'site':['google', 'baidu', 'wiki', 'pandas'],
'age':[18, 39, 22, 45],
'price': [1.0, 2.0, 3.0, 4.0],
'color': ['red', 'black', None, None]}, index=[100, 29, 234, 1])
df.sort_index(ascending=False)
--------------------------------------------------------
site age price color
234 wiki 22 3.0 None
100 google 18 1.0 red
29 baidu 39 2.0 black
1 pandas 45 4.0 None