Python Pandas - 在 MultiIndex 中僅設定一個單一的特定新級別


若要僅在 MultiIndex 中設定一個單一的特定新級別,請將MultiIndex.set_levels()方法與引數 level 結合使用。首先,匯入所需的庫 -

import pandas as pd

MultiIndex 是一個用於 pandas 物件的多級或層次化索引物件。建立陣列 -

arrays = [[1, 2, 3, 4], ['John', 'Tim', 'Jacob', 'Chris']]

“names”引數為每個索引級別設定名稱。from_arrays()用於建立 MultiIndex -

multiIndex = pd.MultiIndex.from_arrays(arrays, names=('ranks', 'student'))

我們使用“level”引數設定了一個新的特定級別 -

print("\nSet a new level in Multi-index...\n",multiIndex.set_levels(['p', 'q', 'r', 's'], level = 0))

範例

程式碼如下 -

import pandas as pd

# MultiIndex is a multi-level, or hierarchical, index object for pandas objects
# Create arrays
arrays = [[1, 2, 3, 4], ['John', 'Tim', 'Jacob', 'Chris']]

# The "names" parameter sets the names for each of the index levels
# The from_arrays() is used to create a MultiIndex
multiIndex = pd.MultiIndex.from_arrays(arrays, names=('ranks', 'student'))

# display the MultiIndex
print("The Multi-index...\n",multiIndex)

# get the levels in MultiIndex
print("\nThe levels in Multi-index...\n",multiIndex.levels)

# set the level in MultiIndex
# We have set a new single specific level using the "level" parameter
print("\nSet a new level in Multi-index...\n",multiIndex.set_levels(['p', 'q', 'r', 's'], level = 0))

輸出

這將產生以下輸出 -

The Multi-index...
MultiIndex([(1,  'John'),
            (2,   'Tim'),
            (3, 'Jacob'),
            (4, 'Chris')],
            names=['ranks', 'student'])

The levels in Multi-index...
   [[1, 2, 3, 4], ['Chris', 'Jacob', 'John', 'Tim']]

Set a new level in Multi-index...
MultiIndex([('p', 'John'),
            ('q', 'Tim'),
            ('r', 'Jacob'),
            ('s', 'Chris')],
            names=['ranks', 'student'])

更新日期: 19-Oct-2021

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