Search⌘ K
Home
Courses
Learn Python 3 Fundamentals

String Formatting

Explore Python string formatting techniques such as f-strings introduced in Python 3.6 and the classic % operator. Understand how to embed variables and format strings for different data types, including numbers and text, to create dynamic and readable output.

We'll cover the following...

String formatting in Python refers to the process of embedding variables or expressions within a string. It allows inserting values into a string at runtime, enabling greater flexibility.

Formatting with f-strings

The f-strings introduces Python 3.6 , also known as formatted string literals, which provide a simple yet understandable approach to format strings. With f-strings, expressions may be embedded directly into string literals, making formatting easier. Here’s an example illustrating the use of the f-strings:

Python 3.10.4
# Basic variable insertion
name = "ABC"
age = 30
print(f"My name is {name} and I am {age} years old")
# Arithmetic operations
a = 10
b = 20
print(f"The sum of {a} and {b} is {a + b}")
# Specifying decimal precision
pi = 3.14159265359
print(f"The value of pi is {pi:.2f}")
print(f"The value of pi is {pi:.5f}")
# Padding with zeros
number1 = 5
number2 = 79
print(f"Number after padding {number1:03}")
print(f"Number after padding {number2:03}")

Explanation

Here’s the code explanation:

  • Line 4: Uses an f-string to insert the values of the variables name and age into the string. Here is the output after using an f-string: My name is ABC and I am 30 years old

  • Line 9: Uses an f-string to insert the values of the variables a and b, and the result of the arithmetic operation a + b, into the string. Here is the output after using an f-string: The sum of 10 and 20 is 30

  • Line 13: Uses an f-string to insert the value of pi into the string, formatted to 2 decimal places. Here is the output after using an f-string: The value of pi is 3.14 ...