Python Pandas CategoricalIndex - 重新排序类别
要对类别进行排序，请使用reorder_categories()Pandas中的CategoricalIndex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“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)获取类别-
print("\nDisplayingCategories from CategoricalIndex...\n",catIndex.categories)使用重新排序类别reorder_categories()。以新顺序设置类别作为参数-
print("\nCategoricalIndex after reordering categories...\n",catIndex.reorder_categories(["r", "s", "q", "p"]))示例
以下是代码-
import pandas as pd
#CategoricalIndex只能采用有限的，通常是固定的可能值（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reorder_categories()重新排序类别
#以新顺序设置类别作为参数
print("\nCategoricalIndex after reordering categories...\n",catIndex.reorder_categories(["r", "s", "q", "p"]))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 reordering categories... CategoricalIndex(['p', 'q', 'r', 's', 'p', 'q', 'r', 's'], categories=['r', 's', 'q', 'p'], ordered=True, dtype='category')