Python Basics · Variables & Types · Lesson 6 of 36

f-strings

Concept

f-strings

f-strings let you embed variables directly inside a string using curly braces.

You can put any expression inside the braces, not just a variable name — including function calls and arithmetic, which get evaluated and inserted automatically.

By the end of this lesson

Explain the core idea behind f-strings.
Predict output before running a change.
Test one realistic and one unusual input.
Use the result to make the next decision.

How to study this page

1. Read one concept.
2. Change the example.
3. Run, compare, and explain.
4. Complete the challenge below.

Syntax

f"text {variable} more text"

ExampleRunnable

name = "Alex"
age = 20
print(f"{name} is {age} years old")

Try it Yourself »

An expression inside an f-string

price = 19.999
print(f"Total: ${price:.2f}")

Note: :.2f formats a number to 2 decimal places, right inside the f-string.

Self-check before continuing

Without looking at the example, describe what changes when you modify one input in f-strings. Then reopen the editor and prove your explanation with a small test.

You are ready to continue when you can predict, test, and explain the result.

Your turn

Use an f-string to print a sentence combining three variables.

Loading editor…

Console

Output will appear here...