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}))
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"]) # Display the CategoricalIndex print("CategoricalIndex...\n",catIndex) # Get the categories print("\nDisplayingCategories from CategoricalIndex...\n",catIndex.categories) # Map categories 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')