Python Pandas CategoricalIndex - 使用输入对应关系（如字典）映射值
要像字典一样使用输入对应关系映射值，请使用Pandas中的方法。首先，导入所需的库-CategoricalIndex.map()
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)映射类别-
print("\nCategoricalIndex after mapping...\n",catIndex.map({'P': 5, 'Q': 10, 'R': 15, 'S': 20}))示例
以下是代码-
import pandas as pd
# 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"])
#DisplaytheCategoricalIndex
print("CategoricalIndex...\n",catIndex)
#Getthecategories
print("\nDisplayingCategories from CategoricalIndex...\n",catIndex.categories)
#Mapcategories
print("\nCategoricalIndex after mapping...\n",catIndex.map({'P': 5, 'Q': 10, 'R': 15, 'S': 20}))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 mapping... CategoricalIndex([5, 10, 15, 20, 5, 10, 15, 20], categories=[5, 10, 15, 20], ordered=True, dtype='category')