Pandas DataFrame Max Method

Introduction

In this lab, we will learn about the max() method in the Pandas DataFrame. This method is used to find the maximum value in a DataFrame. We will explore the syntax, parameters, and how to use this method with examples.

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Skills Graph

Create a DataFrame

First, let's create a DataFrame in order to understand the max() method and how it works. We will use the following code:

import pandas as pd

df = pd.DataFrame({"A": [0, 52, 78], "B": [77, 45, 96], "C": [16, 23, 135], "D": [17, 22, 56]})

print(df)

This code creates a DataFrame with four columns: A, B, C, and D. Each column has three values.

Find Maximum Values Over Index Axis

Next, let's find the maximum values over the index axis (rows) of the DataFrame. We will pass axis=0 as a parameter to the max() method. See the code below:

max_values = df.max(axis=0)

print(max_values)

This code prints the maximum values over the index axis for each column.

Find Maximum Values Over Column Axis

Now, let's find the maximum values over the column axis (columns) of the DataFrame. We will pass axis=1 as a parameter to the max() method. See the code below:

max_values = df.max(axis=1)

print(max_values)

This code prints the maximum values over the column axis for each row.

Include Null Values

Sometimes our DataFrame may contain null values. To include null values when computing the maximum, we can use the skipna=False parameter. See the code below:

df = pd.DataFrame({"A": [0, None, 78], "B": [77, 45, None], "C": [16, 23, None], "D": [17, 22, 56]})

max_values = df.max(axis=0, skipna=False)

print(max_values)

This code prints the maximum values over the index axis, including null values.

Exclude Null Values

To exclude null values when computing the maximum, we can use the skipna=True parameter. See the code below:

df = pd.DataFrame({"A": [0, None, 78], "B": [77, 45, None], "C": [16, 23, None], "D": [17, 22, 56]})

max_values = df.max(axis=0, skipna=True)

print(max_values)

This code prints the maximum values over the index axis, excluding null values.

Summary

In this lab, we learned about the max() method in the Pandas DataFrame. We explored how to find the maximum values over the index axis and column axis, including or excluding null values. The max() method is useful for finding the highest values in a DataFrame and can be applied to various use cases. Make sure to review the syntax and parameters of the max() method to apply it effectively in your own projects.