Python | Customizing output using named placeholders in Python

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Named placeholders

Named placeholders are a way to specify variables in a format string by using names instead of index numbers. This can make the format string more readable and easier to understand, especially when there are many variables to insert. Here's an example:

name = "Alice"

age = 25

print("My name is {name} and I am {age} years old.".format(name=name, age=age))

In this example, the format string is "My name is {name} and I am {age} years old.", which contains two named placeholders, {name} and {age}. The values of these placeholders are specified in the format() method using keyword arguments, {name=name} and {age=age}. The variables name and age are passed as arguments with the same names as the placeholders.

Using named placeholders can make the format string more readable and easier to understand, especially when there are many variables to insert. It also allows you to change the order of the variables without having to change the index numbers in the format string. However, it requires more typing than positional placeholders, and may not be necessary for simple format strings with only a few variables.

Named placeholders are available in Python 3.1 and later. If you're using an older version of Python, you can use positional placeholders with index numbers as an alternative.