String manipulation

Working with text

Now that you know what strings are, let’s learn how to manipulate them. Python gives you powerful tools to work with text.

String operations

Concatenation (joining)

first_name = "Jane"
last_name = "Doe"

# Using +
full_name = first_name + " " + last_name  # "Jane Doe"

# Using f-strings (modern Python way!)
greeting = f"Hello, {first_name}!"  # "Hello, Jane!"

# Multiple variables
age = 25
intro = f"I'm {first_name} and I'm {age} years old"

Repetition

star = "*"
stars = star * 10  # "**********"

separator = "-" * 20  # "--------------------"

String methods

Python strings come with many built-in methods - functions you can call directly on any string. These methods let you transform text, search for patterns, and clean up data. The best part? You can often guess what they do from their names - upper() makes text uppercase, replace() replaces text, and so on.

Changing case

text = "Python Programming"

print(text.lower())      # "python programming"
print(text.upper())      # "PYTHON PROGRAMMING"
print(text.title())      # "Python Programming"

Cleaning strings

messy = "  hello world  "
print(messy.strip())     # "hello world" (removes whitespace)

price = "$19.99"
print(price.strip("$"))  # "19.99"

Finding and replacing

message = "I love Python programming with Python"

# Check if something exists
print("Python" in message)        # True
print(message.startswith("I"))   # True
print(message.endswith("Python")) # True

# Find position
print(message.find("Python"))     # 7 (first occurrence)
print(message.count("Python"))    # 2 (number of times)

# Replace
new_message = message.replace("Python", "JavaScript")
print(new_message)  # "I love JavaScript programming with JavaScript"

Python has over 40 string methods! We’ve covered the most common ones here. For a complete list, check the official Python documentation.

Common mistakes

Forgetting the f in f-strings

# Wrong
name = "Alice"
message = "Hello {name}"  # Prints: "Hello {name}"

# Right
message = f"Hello {name}"  # Prints: "Hello Alice"

Wrong quotes in strings

# Wrong - mismatched quotes
text = 'It's Python'

# Right - escape or use different quotes
text = "It's Python"  # Double quotes outside
text = 'It\'s Python'  # Escape the apostrophe

What’s next?

You’ve mastered working with data! Ready to make your programs smart with decision-making?

Control flow

Learn if statements and loops

Getting started

Data types

Working with data

Control flow

Data structures

Working with text

String operations

Concatenation (joining)

Repetition

String methods

Changing case

Cleaning strings

Finding and replacing

Common mistakes

What’s next?

Control flow

​Working with text

​String operations

​Concatenation (joining)

​Repetition

​String methods

​Changing case

​Cleaning strings

​Finding and replacing

​Common mistakes

​What’s next?

Control flow

Working with text

String operations

Concatenation (joining)

Repetition

String methods

Changing case

Cleaning strings

Finding and replacing

Common mistakes

What’s next?