Python Pandas——設定 MultiIndex 中的級別
要在 MultiIndex 中設定級別,請在 Pandas 中使用 MultiIndex.set_levels() 方法。首先,匯入所需庫 -
import pandas as pd
MultiIndex 是 pandas 物件的多級或分級索引物件。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'))
在 MultiIndex 中設定級別 -
print("\nSet new levels in Multi-index...\n",multiIndex.set_levels([['p', 'q', 'r', 's'], [10, 20, 30, 40]]))
示例
以下是程式碼 -
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 levels in MultiIndex print("\nSet new levels in Multi-index...\n",multiIndex.set_levels([['p', 'q', 'r', 's'], [10, 20, 30, 40]]))
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 new levels in Multi-index... MultiIndex([('p', 30), ('q', 40), ('r', 20), ('s', 10)], names=['ranks', 'student'])
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