Python Strings

Strings are used to represent text in Python.

A string is a sequence of characters enclosed in single quotes (') or double quotes (").

Creating Strings

Example:

name = "John"
city = 'London'

print(name)
print(city)

Output:

John
London

Strings are Arrays

Strings in Python are arrays of characters.

Example:

text = "Python"

print(text[0])

Output:

P

Loop Through a String

You can loop through the characters of a string using a for loop.

Example:

text = "Python"

for char in text:
    print(char)

Output:

P
y
t
h
o
n

String Length

Use the len() function to get the length of a string.

Example:

text = "Hello"

print(len(text))

Output:

5

Check if a String Contains Text

Use the in keyword to check if a string contains a specific word or character.

Example:

text = "Python Programming"

print("Python" in text)

Output:

True

Check if a String Does Not Contain Text

Use the not in keyword.

Example:

text = "Python Programming"

print("Java" not in text)

Output:

True

String Slicing

You can return a range of characters using slicing.

Example:

text = "Python"

print(text[0:4])

Output:

Pyth

Slice From the Beginning

Example:

text = "Python"

print(text[:4])

Output:

Pyth

Slice to the End

Example:

text = "Python"

print(text[2:])

Output:

thon

Negative Indexing

Negative indexes start from the end of the string.

Example:

text = "Python"

print(text[-1])

Output:

n

Modify Strings

Strings are immutable, but you can create a modified copy.

Convert to uppercase:

text = "hello"

print(text.upper())

Output:

HELLO

Convert to lowercase:

text = "HELLO"

print(text.lower())

Output:

hello

Remove Whitespace

Use the strip() method.

Example:

text = "  Hello  "

print(text.strip())

Output:

Hello

Replace Text

Use the replace() method.

Example:

text = "Hello World"

print(text.replace("World", "Python"))

Output:

Hello Python

Split Strings

The split() method splits a string into a list.

Example:

text = "Apple,Banana,Mango"

print(text.split(","))

Output:

['Apple', 'Banana', 'Mango']

Concatenate Strings

Use the + operator to combine strings.

Example:

first = "Hello"
second = "World"

print(first + " " + second)

Output:

Hello World

Escape Characters

Use the backslash (\) to insert special characters.

Example:

text = "It's alright"

print(text)

Output:

It's alright

Or:

text = 'It\'s alright'

print(text)

Output:

It's alright

Summary

• Strings are used to store text.
• Strings can be created with single or double quotes.
• Strings are arrays of characters.
• Use indexing and slicing to access characters.
• Use methods like upper(), lower(), strip(), replace(), and split().
• Use + to join strings.
• Strings are immutable and cannot be changed directly.