Pandas DataFrame Head Method

Introduction

In this lab, we will learn how to use the head() method in the Python pandas library to get the first n rows of a DataFrame. This method is commonly used to quickly inspect the data in a DataFrame and understand its structure.

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Skills Graph

Import the pandas library

First, we need to import the pandas library using the import statement.

import pandas as pd

Create a DataFrame

Next, we'll create a DataFrame object that contains some sample data. For example, let's create a DataFrame with a single column "Language" that contains a list of programming languages.

## Create the DataFrame
df = pd.DataFrame({'Language': ['Kannada','Hindi', 'Telugu', 'Tamil', 'Malyalam','Marathi','Konkani','Tulu']})

Use the head() method

To get the first n rows of the DataFrame, we can use the head() method. By default, it returns the first 5 rows. Here's an example:

print("----First 5 rows of the DataFrame is-----")
print(df.head())

Specify the number of rows

We can also specify the number of rows we want to retrieve by passing a parameter to the head() method. This allows us to get a specific number of rows from the beginning of the DataFrame. For example, to get the first 2 rows, we can use the following code:

print("----First 2 rows of the DataFrame is-----")
print(df.head(n=2))

Use a negative value for n

If we pass a negative value for n to the head() method, it will return all rows except the last n rows. This is equivalent to using slicing notation df[:-n]. Here's an example:

print("----First n rows of the DataFrame is-----")
print(df.head(-2))

Summary

In this lab, we learned how to use the head() method in the pandas library to retrieve the first n rows of a DataFrame. This method is useful for quickly inspecting the data and understanding its structure. By specifying the number of rows, we can retrieve a specific subset of the DataFrame. Additionally, using a negative value for n allows us to retrieve all rows except the last n rows. Overall, the head() method is a handy tool for exploring the contents of a DataFrame.