Python Pandas - 重新排列 MultiIndex 中的级别

要重新排列MultiIndex中的级别，请使用Pandas中的方法。使用order参数设置级别的顺序。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以重新排序级别

print("\nReorder levels in MultiIndex...\n",multiIndex.reorder_levels(order=[2, 0, 1]))

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) #ReorderlevelsofMultiIndex # The "order" parameter is used to set the level in a form to reorder levels print("\nReorder levels in MultiIndex...\n",multiIndex.reorder_levels(order=[2, 0, 1]))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]] Reorder levels in MultiIndex... MultiIndex([(50, 2, Peter), (30, 4, Chris), (40, 3, Andy), (70, 1, Jacob)], names=[points, rank, student])