Convert String Cases in Pandas

How to Convert String Cases in Pandas with Examples

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Python includes methods for converting a string to lower and upper cases.

However, these approaches are inapplicable to lists and other multi-string objects.

The strong ecosystem of data-centric Python packages makes Python an excellent language for data analysis.

Pandas is one of these tools that simplify data import and analysis.

What are pandas in Python?

Pandas is a data analysis library that provides unique methods for translating each sequence value to its associated text case.

“Series.str” must be included in lower, upper, and title Python keywords, Pandas series function calls.

How do you convert a string to a case in Python?

To convert a string to a case in Python, you can apply the islower() and isupper() functions.

isupper() is a built-in sequence technique in Python. This method returns true if every character in the string is uppercase, and false otherwise.

This function is used to determine whether or not the argument contains uppercase letters, such as:

ABCDEFGHIJKLMNOPQRSTUVWXYZ

Example 1:

string = 'PYTHONFORFREE'

print(string.isupper())

Output:

True

Example 2: 

string = 'PythonForFree'

print(string.isupper())

Output:

False

islower() is a built-in sequence technique in Python.

This method returns true if every character in the string is lowercase, and false otherwise.

This function is used to determine whether or not the argument contains uppercase letters, such as:

abcdefghijklmnopqrstuvwxyz

Example 1:

string = 'PythonForFree'

print(string.islower())

Output:

False

Example 2:

string = 'pythonforfree'

print(string.islower())

Output:

True

How do you change String to uppercase in Pandas?

When the character of each word (string) is lowercase or title, the upper() method in Pandas will transform it to uppercase.

In this example, the itsc[‘Names’] invokes the .upper() method, which converts all the data in ‘Names’ to upper case.

Example:

import pandas as pd

data = {'Names': ['paul','prince','grace','gladys','caren']}

pff['Names'] = pff['Names'].str.upper()

print (pff)

Output:

PAUL PRINCE GRACE GLADYS CAREN

Convert a String to Lowercase in Python Pandas

When the character of each word (string) is uppercase or title, the lower() method in Pandas will transform it to lowercase.

In this example, the ‘Names’ calls the .lower() function, so all values in the ‘Names’ data frame are converted to lowercase.

Example:

import pandas as pd 

data = {'Names': ['PAUL','PRINCE','GRACE','GLADYS','CAREN'] 'Age': [22,24,23,22,25]}

pff = pd.DataFrame(data, columns = ['Names', 'Age'])

pff['Names'] = pff['Names'].str.lower()

print (pff)

Output:

Names                 Age

paul                        22

prince                    24

grace                     23

gladys                   22

caren                     25

How do you Change the first letter to Uppercase in Python Pandas?

capitalize() is used to capitalize string elements in the Panda series.

In Python, a series is a sort of data structure that functions identically to a list.

Similar to a list, a series can hold multiple sorts of data as they are entered.

Example:

import pandas as pd

data = {'Names': ['paul','prince','grace','gladys','caren']}

pff['Names'] = pff['Names'].str.capitalize()

print (pff)

Output:

Paul Prince Grace Gladys Care

The Python capitalize() function returns a copy of the original string and converts the string’s first character to an uppercase letter while converting the other characters to lowercase letters.

Convert String Values in Upper and Lower Cases using Python Pandas Series

As mentioned in the former examples, the upper() and lower() methods are used to convert strings in upper and lower cases.

In the case of Pandas Series in Python, .str.upper() is applicable for converting multiple strings in Python into upper case.

Example Program:

import pandas as pd

import numpy as np

print("Pandas Series Uppercase:")

pff = pd.Series(['a', 'ab', 'abc']) 

print(pff.str.upper())

Output:

Pandas Series Uppercase:

A

AB

ABC

On the other hand, .str.lower() is applicable for converting multiple strings in Python into lower case.

Example Program:

import pandas as pd

import numpy as np

print("Pandas Series Lowercase:")

pff = pd.Series(['X', 'XY', 'XYZ']) 

print(pff.str.lower())

Output:

Pandas Series Lowercase:

x

xy

xyz

Summary

In summary, learning how to convert string cases in Pandas is much more useful in Python programming.

It is a one-dimensional data structure that can store text, integers, and even other Python objects.

The Pandas Series in Python is built using the Pandas constructor.

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