Python Pandas CategoricalIndex - 添加新类别
要添加新类别，请使用add_categories()Pandas中的CategoricalIndex方法。首先，导入所需的库-
import pandas as pd
使用“categories”参数设置分类的类别。使用“ordered”参数按顺序处理分类-
catIndex = pd.CategoricalIndex(["p", "q", "r", "s","p", "q", "r", "s"], ordered=True, categories=["p", "q", "r", "s"])
显示分类索引-
print("CategoricalIndex...\n",catIndex)使用add_categories().添加新类别。将新类别设置为参数。新类别将包含在类别的最后/最高位置-
print("\nCategoricalIndex after adding new categories...\n",catIndex.add_categories(["a", "b", "c", "d"]))示例
以下是代码-
import pandas as pd
#CategoricalIndex只能采用有限且通常是固定数量的可能值（类别
# Set the categories for the categorical using the "categories" parameter
# 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"])
#显示分类索引
print("CategoricalIndex...\n",catIndex)
#获取类别
print("\nDisplayingCategories from CategoricalIndex...\n",catIndex.categories)
#使用add_categories()添加新类别
#将新类别设置为参数
#新类别将包含在类别的最后/最高位置
print("\nCategoricalIndex after adding new categories...\n",catIndex.add_categories(["a", "b", "c", "d"]))输出结果这将产生以下输出-
CategoricalIndex... CategoricalIndex(['p', 'q', 'r', 's', 'p', 'q', 'r', 's'], categories=['p', 'q', 'r', 's'], ordered=True, dtype='category') DisplayingCategories from CategoricalIndex... Index(['p', 'q', 'r', 's'], dtype='object') CategoricalIndex after adding new categories... CategoricalIndex(['p', 'q', 'r', 's', 'p', 'q', 'r', 's'], categories=['p', 'q', 'r', 's', 'a', 'b', 'c', 'd'], ordered=True, dtype='category')