What is String Formatting?
String formatting allows us to dynamically insert values into a string. Instead of messy concatenation (+), we can format strings elegantly and efficiently. Think of it as painting a masterpiece, but with text!
Why Use String Formatting?
- Readable and clean code!
- Avoid errors when mixing data types!
- Dynamic text generation!
Using f-strings (Best & Modern Way)
name = "Alice"
age = 25
print(f"Hello, my name is {name} and I am {age} years old.")
# Outputs: Hello, my name is Alice and I am 25 years old.
Formatting Numbers
pi = 3.14159
print(f"Pi rounded to 2 decimal places: {pi:.2f}") # Outputs: Pi rounded to 2 decimal places: 3.14
Using Expressions Inside {}
print(f"Next year, I will be {age + 1} years old!") # Outputs: Next year, I will be 26 years old!
Using .format() (Older but Still Useful)
print("Hello, my name is {} and I am {} years old.".format(name, age))
# Outputs: Hello, my name is Alice and I am 25 years old.
Named Placeholders
print("{greeting}, my name is {person}!".format(greeting="Hi", person=name))
# Outputs: Hi, my name is Alice!
Using % Formatting (Old School)
print("My age is %d years." % age) # Outputs: My age is 25 years.
print("Pi is approximately %.2f" % pi) # Outputs: Pi is approximately 3.14
This method is outdated and not recommended for new projects.
Summary
| Method | Description |
|---|---|
f-strings (f"...") |
Modern, fast, and best for readability |
.format() |
Versatile and supports named placeholders |
% formatting |
Old-school method, not recommended |
0 Comments