Pandas Series.str.center() Method

The Series.str.center() method in Pandas is used to pad both the left and right sides of strings in a Series or Index to a specified width.

This method ensures that the string is centered within the new width, with additional characters filled by a specified fill character. This operation is similar to the string method str.center() in Python.

Syntax

Following is the syntax of the Pandas Series.str.center() method −

Series.str.center(width, fillchar=' ')

Parameters

The Series.str.center() method accepts the following parameters −

• width: An integer specifying the minimum width of the resulting string. Additional characters will be filled with fillchar.
• fillchar: A string specifying the character for filling, default is whitespace.

Return Value

The Series.str.center() method returns a new Series with the strings centered and padded to the specified width using the specified fill character.

Example 1

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

import pandas as pd

# Create a Series of strings
s = pd.Series(['dog', 'lion', 'panda'])

# Display the input Series
print("Input Series")
print(s)

# Center the strings with a width of 8 and fill character '.'
print("Series after calling center with width=8 and fillchar='.':")
print(s.str.center(8, fillchar='.'))

When we run the above code, it produces the following output −

Input Series
0      dog
1     lion
2    panda
dtype: object

Series after calling center with width=8 and fillchar='.':
0    ..dog...
1    ..lion..
2    .panda..
dtype: object

Example 2

This example demonstrates how to use the Series.str.center() method to format the 'Animal' column in a DataFrame, by centering each animal name to a specified width with a custom fill character.

import pandas as pd

# Create a DataFrame
df = pd.DataFrame({'Animal': ['dog', 'lion', 'panda'], 'Legs': [4, 4, 2]})

print("Input DataFrame:")
print(df)

# Center the strings in the 'Animal' column with a width of 8 and fill character '-'
df['Animal'] = df['Animal'].str.center(8, fillchar='-')

print("DataFrame after applying center with width=8 and fillchar='-':")
print(df)

Following is the output of the above code −

Input DataFrame:
  Animal  Legs
0    dog     4
1   lion     4
2  panda     2

DataFrame after applying center with width=8 and fillchar='-':
    Animal  Legs
0  --dog---     4
1  --lion--     4
2  -panda--     2

Example 3

In this example, we apply the Series.str.center() method to an Index object. This showcases how you can use it to format the index labels in a DataFrame by centering them with a specified width and fill character.

import pandas as pd

# Create a DataFrame with an Index
df = pd.DataFrame({'Value': [1, 2, 3]}, index=['first', 'second', 'third'])

# Display the Input DataFrame
print("Input DataFrame:")
print(df)

# Center the index labels with a width of 10 and fill character '*'
df.index = df.index.str.center(10, fillchar='*')

# Display the Modified DataFrame
print("Modified DataFrame:")
print(df)

Output of the above code is as follows −

Input DataFrame:
        Value
first       1
second      2
third       3

Modified DataFrame:
            Value
**first***      1
**second**      2
**third***      3