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))