What are f-strings and how do they compare to other formatting methods?

Python offers several ways to format strings:

f-strings — recommended approach:

Available since Python 3.6. Allow embedding expressions directly in the string.

name = "Anna"
age = 25
print(f"Hello, {name}! You are {age} years old.")
print(f"In 5 years you will be {age + 5}.")
print(f"Name in uppercase: {name.upper()}")

.format() method:

print("Hello, {}! You are {} years old.".format(name, age))
print("Hello, {0}! {0}, you are {1} years old.".format(name, age))

% operator (legacy):

print("Hello, %s! You are %d years old." % (name, age))

Comparison:

• f-strings — the most readable and fastest method. Supports any expressions.
• .format() — useful when the string template is defined in advance.
• % — legacy approach, found in older code.

Number formatting:

pi = 3.14159265
print(f"Pi: {pi:.2f}")          # Pi: 3.14
print(f"Number: {1000000:,}")   # Number: 1,000,000
print(f"Percent: {0.856:.1%}")  # Percent: 85.6%