Python Pandas - 根据底层分类创建索引
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要根据底层分类创建索引，请使用 pandas.CategoricalIndex() 方法。
首先，导入所需的库 −
import pandas as pd
CategoricalIndex 是基于底层分类的索引。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"将分类视为有序的参数 −
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("Categorical Index...\n",catIndex)
获取类别−
print("\nDisplayingCategories from CategoricalIndex...\n",catIndex.categories)
示例
以下是代码 −
import pandas as pd
# CategoricalIndex 是基于底层分类的索引
# 使用 "categories" 参数设置分类的类别
# 使用 "ordered" 将分类视为有序的参数
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("Categorical Index...\n",catIndex)
# 获取类别
print("\nDisplayingCategories from CategoricalIndex...\n",catIndex.categories)
# 获取最小值
print("\nMinimum value from CategoricalIndex...\n",catIndex.min())
#获取最大值
print("\nMaximum value from CategoricalIndex...\n",catIndex.max())
输出
这将产生以下输出 −
Categorical Index... 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') Minimum value from CategoricalIndex... p Maximum value from CategoricalIndex... S
