f-string formatting
- Python course
- Beginner
- Lesson 97/116
- 5 min
Learn number formatting with f"{x:.2f}".
f-strings
An f-string starts with the f prefix and embeds an expression in curly braces {}:
name = "Ayşe"
age = 30
print(f"Merhaba, {name}!")
# Merhaba, Ayşe!
print(f"Yaş: {age + 1}")
# Yaş: 31The expression inside the f-string is evaluated and its result is embedded in the string. Variables, arithmetic, function calls — any expression works.
Python 3.12 also supports nested f-strings and multi-line f-strings.
Format specifiers
After the colon : inside the curly braces comes a format specifier:
score = 95.567
print(f"{score:.1f}") # 95.6
print(f"{score:>10}") # 95.567
print(f"{42:0>5}") # 00042.1f means one decimal, >10 means right-align width 10, 0>5 means zero-fill width 5. These specifiers align output and format numbers.
Format specifiers are valuable for table and report output.
Practice Print score with f-string
Assign "Ayşe" to name. Assign 95.5 to score. Then write print(f"{name}: {score:.1f}").
Starter code
# assign name and score
# format and print with f-stringSample solution
name = "Ayşe"
score = 95.5
print(f"{name}: {score:.1f}")Expected output
Ayşe: 95.5
Questions and answers
Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.
1 Which prints 3.142? (x = 3.14159)
- f'{x:.0f}'
- f'{x:.1f}'
- f'{x:.3f}' Correct answer
- f'{x:.2f}'
Explanation: :.3f shows three decimal places: 3.142.
2 Match format specifiers
| Term | Meaning |
|---|---|
:.2f |
Two decimals |
:>10 |
Right-align |
:0>5 |
Zero-fill |
:.0f |
No decimals |
3 Complete the f-string format
result = f"Score: {score:____}"result = f"Score: {score:.1f}"Explanation: {score:.1f} shows one decimal place.