In lesson 1.5 you saw that combining text and numbers requires converting the number with str() first:

age = 25
print("I am " + str(age) + " years old")

That works, but it gets clunky fast with more variables. Python has a much cleaner tool for this: f-strings.

What is an f-string?

An f-string is a string literal prefixed with f, where anything inside { } is evaluated as Python code and inserted directly — no manual str() conversion needed.

age = 25
print(f"I am {age} years old")

You can put any expression inside the braces, not just a variable:

price = 19.99
quantity = 3
print(f"Total: {price * quantity}")

Multiple values in one f-string

name = "Ada"
age = 28
print(f"{name} is {age} years old")

Formatting numbers

You can control how a number is displayed by adding a format spec after a colon inside the braces. A common one is rounding decimals:

price = 19.9999
print(f"Price: ${price:.2f}")

.2f means "format as a fixed-point decimal with 2 digits after the point."

Try it yourself

Given a name and a score, print a sentence using an f-string in the form: "<name> scored <score> points".

Checkpoint

• f-strings start with f"..." and let you embed expressions in { }.
• No manual str() conversion needed inside an f-string.
• {value:.2f} formats a number to 2 decimal places.