Python Pandas - 在 MultiIndex 中使用级别名称重新排列级别

要在MultiIndex中使用级别名称重新排列级别，请使用Pandas中的方法。传递要重新排列的级别（级别名称）作为参数。MultiIndex.reorder_levels()

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], [Peter, Chris, Andy, Jacob], [50, 30, 40, 70]]

“names”参数设置每个索引级别的名称。将from_arrays()被用来创建一个多指标-

multiIndex = pd.MultiIndex.from_arrays(arrays, names=(rank, student, points))

重新排序MultiIndex的级别。“order”参数用于在表单中设置级别名称以重新排序级别-

print("\nReorder levels in MultiIndex using level name...\n",multiIndex.reorder_levels(order=[student,rank,points]))

示例

以下是代码-

import pandas as pd #MultiIndexisamulti-level,orhierarchical,indexobjectforpandasobjects #Createarrays arrays = [[2, 4, 3, 1], [Peter, Chris, Andy, Jacob], [50, 30, 40, 70]] # The "names" parameter sets the names for each of the index levels #Thefrom_arrays()isusedtocreateaMultiIndex multiIndex = pd.MultiIndex.from_arrays(arrays, names=(rank, student, points)) #displaytheMultiIndex print("The MultiIndex...\n",multiIndex) #getthelevelsinMultiIndex print("\nThe levels in MultiIndex...\n",multiIndex.levels) #swaplevelsofMultiIndexusingswaplevel() #The1stparameteristhefirstlevelofindextobeswapped #The2ndparameteristhesecondlevelofindextobeswapped print("\nSwap levels in MultiIndex...\n",multiIndex.swaplevel(0,2)) #ReorderlevelsofMultiIndex # The "order" parameter is used to set the level name in a form to reorder levels print("\nReorder levels in MultiIndex using level name...\n",multiIndex.reorder_levels(order=[student,rank,points]))输出结果

这将产生以下输出-

The MultiIndex... MultiIndex([(2, Peter, 50), (4, Chris, 30), (3, Andy, 40), (1, Jacob, 70)], names=[rank, student, points]) The levels in MultiIndex... [[1, 2, 3, 4], [Andy, Chris, Jacob, Peter], [30, 40, 50, 70]] Swap levels in MultiIndex... MultiIndex([(Peter, 2, 50), (Chris, 4, 30), ( Andy, 3, 40), (Jacob, 1, 70)], names=[student, rank, points]) Reorder levels in MultiIndex using level name... MultiIndex([(Peter, 2, 50), (Chris, 4, 30), ( Andy, 3, 40), (Jacob, 1, 70)], names=[student, rank, points])