Python Pandas 二元类别索引 - 使用类似字典的新类别重命名类别
要使用类似字典的新类别重命名类别,请在 Pandas 中使用 CategoricalIndex rename_categories() 方法。
首先,导入所需的库 −
import pandas as pd
CategoricalIndex 只能采用有限且通常是固定数量的可能值。使用“ordered”参数将分类视为有序 −
catIndex = pd.CategoricalIndex(["p", "q", "r", "s","p", "q", "r", "s"], ordered=True, categories=["p", "q", "r", "s"])
显示 CategoricalIndex −
print("CategoricalIndex...\n",catIndex)
重命名类别。设置将替换旧类别的新类似字典的类别
print("\nCategoricalIndex after renaming categories...\n",catIndex.rename_categories({'p': 5, 'q': 10, 'r': 15, 's': 20}))
示例
以下为代码 −
import pandas as pd # CategoricalIndex can only take on a limited, and usually fixed, number of possible values # Treat the categorical as ordered using the "ordered" parameter catIndex = pd.CategoricalIndex(["p", "q", "r", "s","p", "q", "r", "s"], ordered=True, categories=["p", "q", "r", "s"]) # Display the CategoricalIndex print("CategoricalIndex...\n",catIndex) # Get the categories print("\nDisplaying Categories from CategoricalIndex...\n",catIndex.categories) # Rename categories # Set the new dict-like categories that will replace the old categories print("\nCategoricalIndex after renaming categories...\n", catIndex.rename_categories({'p': 5, 'q': 10, 'r': 15, 's': 20}))
输出
这将产生以下输出 −
CategoricalIndex... CategoricalIndex(['p', 'q', 'r', 's', 'p', 'q', 'r', 's'], categories=['p', 'q', 'r', 's'], ordered=True, dtype='category') Displaying Categories from CategoricalIndex... Index(['p', 'q', 'r', 's'], dtype='object') CategoricalIndex after renaming categories... CategoricalIndex([5, 10, 15, 20, 5, 10, 15, 20], categories=[5, 10, 15, 20], ordered=True, dtype='category')
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