Python f-Strings: Insert Values into Text 🪄

An f-string lets you build readable text from words, variables, and expressions. It is useful for greetings, game results, program messages, and colored terminal text.

Your First f-String

Place the letter f before the opening quote and put the variable name inside curly braces {}:

name = 'Alex'
level = 5

message = f'Player: {name}. Level: {level}.'
print(message)

Python replaces {name} and {level} with their values:

Player: Alex. Level: 5.

Variables must be created before the f-string. Without the letter f, the braces remain ordinary text.

Expressions Inside Braces

You can put a simple expression inside the braces:

score = 40
bonus = 10

print(f'Total score: {score + bonus}')

Calculate complex values beforehand and store them in a variable so the code remains easy to read.

Why + Does Not Always Work

Adding a string and a number raises TypeError:

age = 16
# print('Age: ' + age)  # TypeError

You could convert the number with str(age), but an f-string is usually clearer:

print(f'Age: {age}')

Another valid option is to pass separate values to print() with a comma:

print('Age:', age)

Multiline f-Strings

The f prefix also works with triple quotes:

name = 'Alex'
status = f"""Pilot: {name}
Status: ready to launch"""

print(status)

If a multiline drawing contains backslashes, you can combine the f and r prefixes:

color = '\033[91m'
reset = '\033[0m'

rocket = fr"""{color}
 /\
/__\
{reset}"""

print(rocket)

In an fr string, f inserts values while r preserves backslashes written in the string itself.

Common Mistakes

• The output contains {name} — add f before the opening quote.
• NameError — create the variable first and check its spelling.
• SyntaxError — check matching quotes, parentheses, and braces.
• You need braces as text — double them: f'{{name}}' prints {name}.

Key Points

• place f immediately before the opening quote;
• write values and expressions inside {};
• create variables before using them;
• use fr when you need both substitutions and literal backslashes.