How does Python handle string interpolation?

String Concatenation in Python: Methods and Examples

Embedding variable values or expressions directly into a string is called string interpolation in Python. It allows you to insert variable values or expression results directly into strings dynamically. This makes the code more concise and readable.

There are two main ways to interpolate strings in Python:

Using f-strings (Formatted String Literals):

As of Python 3.6, F-strings are available. They provide a simple and efficient way to interpolate strings. F-strings are created by placing an f or F prefix before the string literal, followed by curly braces {} to include variable names or expression.

Example using f-strings:

Code:

name = "mobile"
ctr = 5
result = f"There are {ctr} types of {name} in the shop."
print(result)

Output:

There are 5 types of mobile in the shop.

During runtime, the expressions inside the curly braces {} are evaluated, and their values are inserted into the string. Any valid Python expression can be included inside the curly braces, allowing for more complex interpolations.

Using the .format() method:

The .format() method is available in Python 2.6 and all later versions, including Python 3.x. This method inserts variable values into a string using placeholder curly braces {}. Due to its compatibility with all Python versions, .format() is a more versatile method than f-strings.

Code:

name = "mobile"
ctr = 5
result = "There are {} types of {} in the shop.".format(ctr, name)
print(result)

Output:

There are 5 types of mobile in the shop.

Note:
A curly brace {} acts as a placeholder for values you want to interpolate in the .format() method. Using the .format() method, we can provide values as arguments, and they will be inserted into the string in the order they appear.