In this tutorial, you'll learn about Python strings and their basic operations with examples, explanations, and beginner-friendly exercises.

Introduction to Python Strings

A string is a sequence of characters. In Python, anything enclosed in quotes is considered a string. You can use either single (') or double (") quotes:

message = 'This is a string in Python'
message = "This is also a string"

Handling Quotes Inside Strings

If the string contains a single quote, wrap it in double quotes:

message = "It's a string"

If the string contains double quotes, wrap it in single quotes:

message = '"Beautiful is better than ugly.". Said Tim Peters'

Escaping Characters

Use the backslash (\) to escape characters:

message = 'It\'s also a valid string'

Raw Strings

Use raw strings to treat backslashes as literal characters:

message = r'C:\python\bin'

Creating Multiline Strings

Use triple quotes (''' or """) to define strings that span multiple lines:

help_message = '''
Usage: mysql command
    -h hostname
    -d database name
    -u username
    -p password
'''

print(help_message)

Output:

Usage: mysql command
    -h hostname
    -d database name
    -u username
    -p password

Using Variables in Strings (f-strings)

Use f-strings to embed variables in string literals. Introduced in Python 3.6:

name = 'John'
message = f'Hi {name}'
print(message)

Output:

Hi John

Concatenating Strings

Literal Concatenation:

greeting = 'Good ' 'Morning!'
print(greeting)

Variable Concatenation:

greeting = 'Good '
time = 'Afternoon'

message = greeting + time + '!'
print(message)

Output:

Good Afternoon!

Accessing Characters in a String

Strings are sequences, so you can use indexing:

text = "Python String"
print(text[0])  # P
print(text[1])  # y

Negative Indexing

print(text[-1])  # g
print(text[-2])  # n

Index Diagram

+---+---+---+---+---+---+---+---+---+---+---+---+---+
| P | y | t | h | o | n |   | S | t | r | i | n | g |
+---+---+---+---+---+---+---+---+---+---+---+---+---+
  0   1   2   3   4   5   6   7   8   9   10  11  12
 -13 -12 -11 -10 -9  -8  -7  -6  -5  -4  -3  -2  -1

Getting the Length of a String

Use len() to get the number of characters:

text = "Python String"
length = len(text)
print(length)

Output:

13

Slicing Strings

Use slicing to extract substrings:

text = "Python String"
print(text[0:2])

Output:

Py

Syntax:

string[start:end]

  • Includes character at start

  • Excludes character at end

  • Omitting start = from beginning

  • Omitting end = to end

Strings Are Immutable

Python strings cannot be changed in-place. Trying to do so raises an error:

text = "Python String"
text[0] = 'J'  # Error

Correct way to create a modified string:

text = "Python String"
new_text = 'J' + text[1:]
print(new_text)

Output:

Jython String

More f-string Examples

name = 'Anthony'
message = f'Hello, {name}!'
print(message)

Output:

Hello, Anthony!

Explanation:

  • Use f'' or f"" before the string

  • Embed variables using {}

Exercises

Exercise 1:

Create a string variable called city with the name of your city. Use print() to show a welcome message.

city = 'New York'
print(f'Welcome to {city}!')

Exercise 2:

Use string concatenation to create a greeting.

greeting = 'Hello'
name = 'Maria'
message = greeting + ', ' + name + '!'
print(message)

Exercise 3:

Access the first and last letters of a string using index and negative index.

word = 'Developer'
print('First letter:', word[0])
print('Last letter:', word[-1])

Exercise 4:

Slice a string to get a part of it.

language = 'JavaScript'
print('First four letters:', language[0:4])

Exercise 5:

Use f-strings to include variables in a string.

first_name = 'Lena'
last_name = 'Smith'
print(f'User: {first_name} {last_name}')

Summary

  • A string is a sequence of characters surrounded by quotes.

  • Strings can use either single or double quotes.

  • Use \ to escape characters and r'' for raw strings.

  • Use triple quotes for multiline strings.

  • Use f-strings (f"{var}") to insert variables.

  • Concatenate strings with + or by placing literals next to each other.

  • Use len() to get the string’s length.

  • Access individual characters with indexes (positive or negative).

  • Use slicing string[start:end] to extract substrings.

  • Strings are immutable; create a new string to modify it.

  • Practice with exercises to reinforce what you've learned.

 

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