Python Tutorials

Choose a lesson to begin

Hello World and Print Statements
Learn the basics of printing output in Python
Beginner
Variables and Data Types
Store and work with different types of data
Beginner
Math and Arithmetic
Perform calculations and mathematical operations
Beginner
F-Strings and Formatting
Format text output with embedded variables
Beginner
String Methods
Transform and manipulate text with built-in methods
Beginner
Lists and For Loops
Store multiple items and iterate through them
Beginner
List Comprehensions and Generator Expressions
Master concise, Pythonic ways to create and transform sequences
Intermediate
Dictionaries and Advanced Data Structures
Master key-value mappings, nested structures, and efficient data organization
Intermediate
Functions, Decorators, and Functional Programming
Write reusable code with functions, decorators, lambda expressions, and functional patterns
Intermediate
Object-Oriented Programming (OOP)
Master classes, objects, inheritance, and OOP design patterns
Advanced
Error Handling and Exceptions
Handle errors gracefully with try-except, custom exceptions, and error recovery
Intermediate
File I/O and Data Persistence
Read and write files, work with JSON/CSV, and persist application data
Advanced

F-Strings and Formatting

F-strings (formatted string literals) let you embed variables and expressions directly in your text. They make your output clean and readable!

Basic F-Strings

Add an f before the opening quote, then put variables in {curly braces}:

name = "Bob"
print(f"Hello, {name}!")

Output: Hello, Bob!

Multiple Variables

Include as many variables as you need:

first_name = "Vidar"
last_name = "Smith"
age = 30
print(f"{first_name} {last_name} is {age} years old")

Output: Vidar Smith is 30 years old

Expressions in F-Strings

You can put calculations directly in the braces:

age = 25
print(f"Next year you'll be {age + 1}")
print(f"In 5 years you'll be {age + 5}")

Output: 

Next year you'll be 26
In 5 years you'll be 30

String Methods in F-Strings

name = "Vidar"
print(f"Hello, {name.upper()}!")

Output: Hello, VIDAR!

Why F-Strings?

Without f-strings (the old way): 

name = "Vidar"
age = 22
print(name, "is", age, "years old")  # Awkward spacing

With f-strings (clean and clear): 

name = "Vidar"
age = 22
print(f"{name} is {age} years old")

Real-World Examples

Game Score Display

player = "Hero"
score = 1500
level = 5
print(f"Player: {player}")
print(f"Score: {score}")
print(f"Level: {level}")

Shopping Receipt

item = "Laptop"
price = 899.99
quantity = 1
tax_rate = 0.08
subtotal = price * quantity
tax = subtotal * tax_rate
total = subtotal + tax
print(f"Item: {item}")
print(f"Price: {price}")
print(f"Tax: {tax}")
print(f"Total: {total}")

Temperature Conversion

celsius = 25
fahrenheit = (celsius * 9/5) + 32
print(f"{celsius}°C is {fahrenheit}°F")

Output: 25°C is 77.0°F

Multiple Lines

Create multi-line output:

name = "Vidar"
city = "Roskilde"
country = "Denmark"
print(f"Name: {name}")
print(f"City: {city}")
print(f"Country: {country}")

F-String Quotes

Use different quotes to avoid conflicts:

# use double quotes for f-string, single inside
message = f"She said, 'Hello!'"
# or vice versa
message = f'He said, "Goodbye!"'

Common Patterns

Labeling output: 

score = 95
print(f"Score: {score}")

Creating sentences: 

name = "Bob"
job = "developer"
print(f"{name} is a {job}")

Showing calculations: 

width = 10
height = 5
print(f"Area: {width * height}")

Try It Out!

  • Create variables for a person (name, age, city) and print a bio using f-strings
  • Make a simple calculator that shows: "10 + 5 = 15"
  • Create a movie ticket receipt (movie name, price, quantity, total)
  • Print your height in both feet and inches: "I am 5 feet 9 inches tall"

    • Pro Tips

    Next Steps

    Ready to work with text? Learn about String Methods to manipulate and transform text!

    🐍 Python Runner