Pandas Series.str.capitalize() Method

TheSeries.str.capitalize() method in Pandas is used to capitalize the first character of each string in a Series or Index. This method is a convenient way to standardize the case of text data, ensuring that each string starts with an uppercase letter and the rest are in lowercase. This operation is similar to the string methodstr.capitalize() in Python.

Syntax

Following is the syntax of the PandasSeries.str.capitalize() method −

Series.str.capitalize()

Parameters

TheSeries.str.capitalize() method does not accept any parameters.

Return Value

TheSeries.str.capitalize() method returns a new Series with the first letter of each string capitalized and all other letters in lowercase.

Example 1

In this example, we demonstrate the basic usage of theSeries.str.capitalize() method by applying it to a Series of strings.

import pandas as pd# Create a Series of stringss = pd.Series(['hi,', 'welcome to', 'tutorialspoint'])# Display the input Seriesprint("Input Series")print(s)# Capitalize the first letter of each stringprint("Series after calling the Capitalize:")print(s.str.capitalize())

When we run the above code, it produces the followingoutput −

Input Series0               hi,1        welcome to2    tutorialspointdtype: objectSeries after calling the Capitalize:0               Hi,1        Welcome to2    Tutorialspointdtype: object

Example 2

This example demonstrates how to use theSeries.str.capitalize() method to format the 'Day' column in a DataFrame, converting each day's name to proper capitalization.

import pandas as pd# Create a DataFramedf = pd.DataFrame({'Day': ['mon', 'tue', 'wed', 'thu', 'fri'],                   'Subject': ['Math', 'english', 'science', 'music', 'games']})print("Input DataFrame:")print(df)# Capitalize the first letter of each daydf.Day = df.Day.str.capitalize()print("DataFrame after applying Capitalize:")print(df)

Following is theoutput of the above code −

Input DataFrame:   Day  Subject0  mon     Math1  tue  english2  wed  science3  thu    music4  fri    gamesDataFrame after applying Capitalize:   Day  Subject0  Mon     Math1  Tue  english2  Wed  science3  Thu    music4  Fri    games

Example 3

In this example, we apply theSeries.str.capitalize() method to an Index object. This showcases how you can use it to format the index labels in a DataFrame.

import pandas as pd# Create a DataFrame with an Indexdf = pd.DataFrame({'Value': [1, 2, 3]}, index=['first', 'second', 'third'])# Capitalize the first letter of each index labeldf.index = df.index.str.capitalize()print(df)

Output of the above code is as follows −

       ValueFirst      1Second     2Third      3