Python Pandas 二元類別索引 - 使用類似字典的新類別重新命名類別


要使用類似字典的新類別重新命名類別,請在 Pandas 中使用 CategoricalIndex rename_categories() 方法。

首先,匯入所需的庫 −

import pandas as pd

CategoricalIndex 只能採用有限且通常是固定數量的可能值。使用“ordered”引數將分類視為有序 −

catIndex = pd.CategoricalIndex(["p", "q", "r", "s","p", "q", "r", "s"], ordered=True, categories=["p", "q", "r", "s"])

顯示 CategoricalIndex −

print("CategoricalIndex...\n",catIndex)

重新命名類別。設定將替換舊類別的新類似字典的類別

print("\nCategoricalIndex after renaming categories...\n",catIndex.rename_categories({'p': 5, 'q': 10, 'r': 15, 's': 20}))

示例

以下為程式碼 −

import pandas as pd

# CategoricalIndex can only take on a limited, and usually fixed, number of possible values
# 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("\nDisplaying Categories from CategoricalIndex...\n",catIndex.categories)

# Rename categories
# Set the new dict-like categories that will replace the old categories
print("\nCategoricalIndex after renaming categories...\n",
catIndex.rename_categories({'p': 5, 'q': 10, 'r': 15, 's': 20}))

輸出

這將產生以下輸出 −

CategoricalIndex...
CategoricalIndex(['p', 'q', 'r', 's', 'p', 'q', 'r', 's'], categories=['p', 'q', 'r', 's'], ordered=True, dtype='category')

Displaying Categories from CategoricalIndex...
Index(['p', 'q', 'r', 's'], dtype='object')

CategoricalIndex after renaming categories...
CategoricalIndex([5, 10, 15, 20, 5, 10, 15, 20], categories=[5, 10, 15, 20], ordered=True, dtype='category')

更新於:2021 年 10 月 18 日

95 次瀏覽

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