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

2024-05-20 15:51:04 269

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'])

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

示例

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