Pandas DataFrame Idxmax Method

Introduction

In this step-by-step lab, you will learn about the Python pandas DataFrame.idxmax() method. This method is used to get the index of the first occurrence of the maximum value over the specified axis in a DataFrame. It excludes any null or missing values in the calculation.

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Skills Graph

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Import the necessary libraries and create a DataFrame

First, import the pandas library using the import statement:

import pandas as pd

Next, create a DataFrame using the pd.DataFrame() constructor:

df = pd.DataFrame({'Marks_1': [85, 90, 45], 'Marks_2': [85, 96, 100]}, index=['Kannada', 'English', 'Science'])

Display the DataFrame

To see the contents of the DataFrame, use the print() function:

print(df)

Use the DataFrame.idxmax() method to get the index of the maximum value over the row axis

To get the index of the maximum value in each column, use the idxmax() method on the DataFrame:

print(df.idxmax())

Use the DataFrame.idxmax() method to get the index of the maximum value over the column axis

To get the index of the maximum value in each row, use the idxmax() method on the DataFrame and specify the axis="columns" parameter:

print(df.idxmax(axis="columns"))

Summary

In this lab, you learned about the Python pandas DataFrame.idxmax() method. This method is used to get the index of the first occurrence of the maximum value over the specified axis in a DataFrame. By following the steps provided, you were able to import the necessary libraries, create a DataFrame, and use the idxmax() method to get the desired index values. This method is useful for analyzing data and finding the location of maxima in a DataFrame.