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"]))
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')