獲取和設定 Pandas DataFrame 索引名

Suraj Joshi 2023年1月30日 2021年1月22日
  1. 獲取 DataFrame 中索引列的名稱
  2. 通過設定 name 屬性來設定 DataFrame 的索引列的名稱
  3. 使用 rename_axis() 方法設定 DataFrame 的索引列的名稱
獲取和設定 Pandas DataFrame 索引名

本教程介紹瞭如何在 Pandas DataFrame 中設定和獲取索引列的名稱。我們將在文章中使用下面的 DataFrame 示例。

import pandas as pd

my_df = pd.DataFrame({
    'Applicant': ['Ratan', 'Anil', 'Mukesh', 'Kamal'],
    'Hometown': ['Delhi', 'Pune', 'Dhangadi', 'Kolkata'],
    'Score': [85,87,90,89],

},index=["2021-01-03","2021-01-04","2021-01-05","2021-01-06"])

print(my_df)

輸出:

           Applicant  Hometown  Score
2021-01-03     Ratan     Delhi     85
2021-01-04      Anil      Pune     87
2021-01-05    Mukesh  Dhangadi     90
2021-01-06     Kamal   Kolkata     89

獲取 DataFrame 中索引列的名稱

我們可以通過索引列的 name 屬性來獲取 DataFrame 的索引列的名稱。

import pandas as pd

my_df = pd.DataFrame({
    'Applicant': ['Ratan', 'Anil', 'Mukesh', 'Kamal'],
    'Hometown': ['Delhi', 'Pune', 'Dhangadi', 'Kolkata'],
    'Score': [85,87,90,89],

},index=["2021-01-03","2021-01-04","2021-01-05","2021-01-06"])

print("The DataFrame is:")
print(my_df,"\n")

print("Name of Index Column of the DataFrame is:")
print(my_df.index.name)

輸出:

The DataFrame is:
           Applicant  Hometown  Score
2021-01-03     Ratan     Delhi     85
2021-01-04      Anil      Pune     87
2021-01-05    Mukesh  Dhangadi     90
2021-01-06     Kamal   Kolkata     89

Name of Index Column of the DataFrame is:
None

由於我們沒有為 my_df DataFrame 設定索引列的名稱,所以得到 my_df DataFrame 的索引列名稱為 None

通過設定 name 屬性來設定 DataFrame 的索引列的名稱

我們只需設定 DataFrame 的 index 屬性的 name 值,就可以設定 DataFrame 的索引列的名稱。

import pandas as pd

my_df = pd.DataFrame({
    'Applicant': ['Ratan', 'Anil', 'Mukesh', 'Kamal'],
    'Hometown': ['Delhi', 'Pune', 'Dhangadi', 'Kolkata'],
    'Score': [85,87,90,89],

},index=["2021-01-03","2021-01-04","2021-01-05","2021-01-06"])

print("Initial DataFrame:")
print(my_df,"\n")

my_df.index.name="Date"

print("DataFrame after setting the name of Index Column:")
print(my_df,"\n")

print("Name of Index Column of the DataFrame is:")
print(my_df.index.name)

輸出:

Initial DataFrame:
           Applicant  Hometown  Score
2021-01-03     Ratan     Delhi     85
2021-01-04      Anil      Pune     87
2021-01-05    Mukesh  Dhangadi     90
2021-01-06     Kamal   Kolkata     89

DataFrame after setting the name of Index Column:
           Applicant  Hometown  Score
Date
2021-01-03     Ratan     Delhi     85
2021-01-04      Anil      Pune     87
2021-01-05    Mukesh  Dhangadi     90
2021-01-06     Kamal   Kolkata     89

Name of Index Column of the DataFrame is:
Date

它將 my_dfindex 屬性值設定為 Date

使用 rename_axis() 方法設定 DataFrame 的索引列的名稱

我們可以將索引列的名稱作為引數傳遞給 rename_axis() 方法來設定 DataFrame 中索引列的名稱。

import pandas as pd

my_df = pd.DataFrame({
    'Applicant': ['Ratan', 'Anil', 'Mukesh', 'Kamal'],
    'Hometown': ['Delhi', 'Pune', 'Dhangadi', 'Kolkata'],
    'Score': [85,87,90,89],

},index=["2021-01-03","2021-01-04","2021-01-05","2021-01-06"])

print("Initial DataFrame:")
print(my_df,"\n")

my_df=my_df.rename_axis('Date')

print("DataFrame after setting the name of Index Column:")
print(my_df,"\n")

print("Name of Index Column of the DataFrame is:")
print(my_df.index.name)

輸出:

Initial DataFrame:
           Applicant  Hometown  Score
2021-01-03     Ratan     Delhi     85
2021-01-04      Anil      Pune     87
2021-01-05    Mukesh  Dhangadi     90
2021-01-06     Kamal   Kolkata     89

DataFrame after setting the name of Index Column:
           Applicant  Hometown  Score
Date
2021-01-03     Ratan     Delhi     85
2021-01-04      Anil      Pune     87
2021-01-05    Mukesh  Dhangadi     90
2021-01-06     Kamal   Kolkata     89

Name of Index Column of the DataFrame is:
Date

它使用 rename_axis() 方法將 DataFrame my_dfindex 列名設定為 Date

Author: Suraj Joshi
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Suraj Joshi is a backend software engineer at Matrice.ai.

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