Working with Strings in Python 3 - GeeksforGeeks (2024)

Last Updated : 31 Jul, 2023

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In Python, sequences of characters are referred to as Strings. It used in Python to record text information, such as names. Python strings are “immutable” which means they cannot be changed after they are created.

Creating a String

Strings can be created using single quotes, double quotes, or even triple quotes. Python treats single quotes the same as double-quotes.

Python3

# creating string

# with single Quotes

String = 'Hello Geek'

print("Creating string with single quotes :", String)

# Creating String

# with double Quotes

String = "yes, I am Geek"

print("Creating String with double quotes :", String)

# Creating String

# with triple Quotes

String = '''yes, I am Geek'''

print("Creating String with triple quotes :", String)

Output

Creating string with single quotes : Hello GeekCreating String with double quotes : yes, I am GeekCreating String with triple quotes : yes, I am Geek

Note: Be careful with quotes!

Python3

# creating string

# with single quotes

String = 'Yes' I am geek'

print(String)

Output

 File "<ipython-input-10-794636cfedda>", line 3 String = 'Yes' I am geek' ^SyntaxError: invalid syntax

The reason for the error above is the single quote in Yes’ I stopped the string. If you want to print ‘WithQuotes’ in python, this can’t be done with only single (or double) quotes alone, it requires simultaneous use of both. The best way to avoid this error use double-quotes.

Example:

Python3

# this code prints the output within quotes.

# print WithQuotes within single quotes

print("'WithQuotes'")

print("Hello 'Python'")

# print WithQuotes within single quotes

print('"WithQuotes"')

print('Hello "Python"')

Output

'WithQuotes'Hello 'Python'"WithQuotes"Hello "Python"

String Indexing

Strings are a sequence of characters, which means Python can use indexes to call parts of the sequence. There are two ways of indexing.

Positive Indexing
Negative Indexing

Positive indexing

Python3

# creating a string

String = "GEEK"

# Show first element in string

print("The 1st element is : ", String[0])

# Show 2nd element in string

print("The 2nd element is : ", String[1])

print("The 3rd element is : ", String[2])

print("The 4th element is : ", String[3])

Output

The 1st element is : GThe 2nd element is : EThe 3rd element is : EThe 4th element is : K

Negative indexing

Python3

# creating a string

String = "GEEK"

# Show last element in string

print("The 4th element is : ", String[-1])

# Show all element in string

print("The 3rd element is : ", String[-2])

print("The 2nd element is : ", String[-3])

print("The 1th element is : ", String[-4])

Output

The 4th element is : KThe 3rd element is : EThe 2nd element is : EThe 1th element is : G

Updating Strings

In Python, Updation or deletion of characters from a string is not allowed. This will cause an error because item assignment or item deletion from a String is not supported. Python can allow you to reassign a new string to an existing one string.

Python3

# Creating string

String = "Geeks"

# assign new character

String[0] = "Hi!, Geeks"

Output

Traceback (most recent call last): File “/home/b298782a4e04df4950426bf4bd5bee99.py”, line 5, in <module> String[0] = “Hi!, Geeks” TypeError: ‘str’ object does not support item assignment

Updating the entire String

Python3

# Creating string

String Slicing

Python slicing is about obtaining a sub-string from the given string by slicing it respectively from start to end.
Python slicing can be done in two ways.

slice() Constructor
Extending Indexing

Python3

# Creating a String

String = "Geekforgeeks"

s1 = slice(3)

# print everything except the first element

print(String[s1])

# print everything UP TO the 6th index

print(String[:6])

# print everything between both index

print(String[1:7])

Output

GeeGeekfoeekfor

Slicing with negative Index.

Python3

# Creating a String

String = "Geekforgeeks"

s1 = slice(-1)

# print everything except the last element

print(String[s1])

# print everything between both index

print(String[0:-3])

Output

GeekforgeekGeekforge

We can use [ : : ] for specifying the frequency to print elements. It specifies the step after which every element will be printed starting from the given index. If nothing is given then it starts from the 0th index.

Python3

# Creating a String

String = "Geekforgeeks"

# print everything with step 1

print(String[::1])

# print everything with step 2

print(String[2::2])

# print a string backwards

print(String[::-1])

Output

GeekforgeeksefrekskeegrofkeeG

Note: For more information, refer String Slicing in Python

String Formatting

str.format() and f-strings methods are used to add formatted objects to printed string statements. The string format() method formats the given string. It allows for multiple substitutions and value formatting.

Python3

# using format option in a simple string

String = 'Geeksforgeeks'

print("{}, A computer science portal for geeks."

.format(String))

String = 'Geeks'

print("Hello {}, How are you ?".format(String))

# formatting a string using a numeric constant

val = 2

print("I want {} Burgers! ".format(val))

Output

Geeksforgeeks, A computer science portal for geeks.Hello Geeks, How are you ?I want 2 Burgers!

Note: For more information, refer Python | format() function

Formatted f-string literals are prefixed with ‘f’ and curly braces { } containing expressions that will be replaced with their values.

Python3

# Creating string

String = 'GeekForGeeks'

print(f"{String}: A Computer Science portal for geeks")

# Creating string

String = 'Geek'

print(f"Yes, I am {String}")

# Manuplating int within {}

bags = 3

book_in_bag = 12

print(f'There are total {bags * book_in_bag} books')

# work with dictionaries in f-strings

Dic = {'Portal': 'Geeksforgeeks', 'for': 'Geeks'}

print(f"{Dic['Portal']} is a computer science portal for {Dic['for']}")

Output

GeekForGeeks: A Computer Science portal for geeksYes, I am GeekThere are total 36 booksGeeksforgeeks is a computer science portal for Geeks

Note:For more information, referf-strings in Python 3 – Formatted string literals

Related Resources:

To learn more about Python 3, visit: Python 3 Tutorial

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Python String

Why are Python Strings Immutable?

Working with Strings in Python 3 - GeeksforGeeks (2024)

Creating a String

Python3

Python3

Python3

String Indexing

Python3

Python3

Updating Strings

Python3

Python3

String Slicing

Python3

Python3

Python3

String Formatting

Python3

Python3

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