Python Pandas - 如何对多索引进行排序
要创建MultiIndex，请使用from_arrays()方法。但是，要对MultiIndex进行排序，请使用.Pandas中的方法。multiIndex.sortlevel()
首先，导入所需的库-
import pandas as pd
MultiIndex是Pandas对象的多级或分层索引对象。创建数组-
arrays = [[2, 4, 3, 1], ['John', 'Tim', 'Jacob', 'Chris']]
“names”参数设置每个索引级别的名称。将from_arrays()用于创建一个MultiInde-
multiIndex = pd.MultiIndex.from_arrays(arrays, names=('ranks', 'student'))排序多索引。默认排序在级别0-
print("\nSort MultiIndex...\n",multiIndex.sortlevel())示例
以下是代码-
import pandas as pd
#MultiIndexisamulti-level,orhierarchical,indexobjectforpandasobjects
#Createarrays
arrays = [[2, 4, 3, 1], ['John', 'Tim', 'Jacob', 'Chris']]
# The "names" parameter sets the names for each of the index levels
#Thefrom_arrays()isusedtocreateaMultiIndex
multiIndex = pd.MultiIndex.from_arrays(arrays, names=('ranks', 'student'))
#displaytheMultiIndex
print("The Multi-index...\n",multiIndex)
#getthelevelsinMultiIndex
print("\nThe levels in Multi-index...\n",multiIndex.levels)
#SortMultiIndex
#Thedefaultsortsatlevel0
print("\nSort MultiIndex...\n",multiIndex.sortlevel())输出结果这将产生以下输出-
The Multi-index...
MultiIndex([(2, 'John'),
(4, 'Tim'),
(3, 'Jacob'),
(1, 'Chris')],
names=['ranks', 'student'])
The levels in Multi-index...
[[1, 2, 3, 4], ['Chris', 'Jacob', 'John', 'Tim']]
Sort MultiIndex...
(MultiIndex([(1, 'Chris'),
(2, 'John'),
(3, 'Jacob'),
(4, 'Tim')],
names=['ranks', 'student']), array([3, 0, 2, 1], dtype=int64))