Strings in Python

We work with text all the time in programming—names, messages, addresses, usernames, and much more. In Python, text is stored using a string.

Strings are one of the most commonly used data types, so it's important to understand how they work.

What is a String?

A string is a sequence of characters used to represent text.

Strings are written inside quotes:

name = "John"
message = 'Hello, Python!'

Both single (' ') and double (" ") quotes can be used.

language = "Python"

is the same as:

language = 'Python'

Creating Strings

You can create a string by assigning text to a variable:

name = "John"
city = "Delhi"
course = "Python Programming"

You can also print strings directly:

print("Hello, World!")

Strings Can Contain Numbers and Symbols

A string doesn't have to contain only letters.

phone = "9876543210"
price = "$99.99"
code = "A123"

Even though some of these look like numbers, they're strings because they're written inside quotes.

For example:

age = "20"

Here age is a string, not an integer.

Multiline Strings

If you need to store text across multiple lines, you can use triple quotes:

message = """Hello John,
Welcome to Python!
Let's start learning."""

print(message)

Output:

Hello John,
Welcome to Python!
Let's start learning.

Triple-quoted strings can also be useful for documentation and docstrings.

Accessing Characters

A string is a sequence of characters, and each character has an index.

Python starts indexing from 0.

word = "Python"

Its indexes look like this:

 P   y   t   h   o   n
 0   1   2   3   4   5

So we can access individual characters:

word = "Python"

print(word[0])
print(word[2])

Output:

P
t

Negative Indexing

Python also supports negative indexes.

 P   y   t   h   o   n
-6  -5  -4  -3  -2  -1

For example:

word = "Python"

print(word[-1])

Output:

n

String Slicing

Slicing lets us extract part of a string.

word = "Python"

print(word[0:3])

Output:

Pyt

The syntax is:

string[start:end]

The end index is not included.

You can also leave out the start or end:

word = "Python"

print(word[:3])
print(word[3:])

Output:

Pyt
hon

Joining Strings

You can combine strings using the + operator.

first_name = "John"
last_name = "Smith"

full_name = first_name + " " + last_name

print(full_name)

Output:

John Smith

Repeating Strings

The * operator can repeat a string.

print("Hi! " * 3)

Output:

Hi! Hi! Hi!

Finding the Length

The len() function tells you how many characters a string contains.

name = "John"

print(len(name))

Output:

4

Spaces are also counted as characters.

text = "Hello World"

print(len(text))

Strings are Immutable

One important thing to know is that strings cannot be changed directly after they are created.

For example, this won't work:

word = "Python"
word[0] = "J"

Python will raise an error.

Instead, you can create a new string:

word = "Python"
word = "J" + word[1:]

print(word)

Output:

Jython

Useful String Operations

Python provides many methods for working with strings.

For example:

text = "hello python"

print(text.upper())
print(text.lower())
print(text.title())

Output:

HELLO PYTHON
hello python
Hello Python

We'll cover these and other string methods in detail in a separate topic.

Checking Text Inside a String

You can use in to check whether some text exists inside another string.

message = "I am learning Python"

print("Python" in message)

Output:

True

You can also use not in:

print("Java" not in message)

Output:

True

Escape Characters

Sometimes you need to include special characters inside a string.

For example, to include quotation marks:

message = "He said, \"Hello!\""

print(message)

Output:

He said, "Hello!"

The backslash (\) is called an escape character.

Some commonly used escape sequences are:

Example:

print("Hello\nJohn")

Output:

Hello
John

Using f-Strings

f-strings make it easy to include variables inside strings.

name = "John"
age = 20

print(f"My name is {name} and I am {age} years old.")

Output:

My name is John and I am 20 years old.

You'll use f-strings frequently when creating formatted output.

A Practical Example

Let's create a simple welcome message:

name = input("Enter your name: ")
language = "Python"

print(f"Hello {name}!")
print(f"Welcome to {language} programming.")

If the user enters John:

Hello John!
Welcome to Python programming.

Strings may seem simple at first, but you'll use them everywhere in Python—from displaying messages to processing user input and handling data.