Python | Customizing output using format specifiers in Python

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Format specifier

A format specifier is a special syntax used in format strings to control the formatting of values that are inserted into the string. A format specifier consists of one or more format codes that are placed after a variable name in the format string. Here's an example:

name = "Alice"

age = 25

print("My name is {0:10} and I am {1:5} years old.".format(name, age))

In this example, the format string contains two placeholders, {0:10} and {1:5}, which specify the width of the corresponding values using format specifiers. The : character is used to separate the variable name from the format specifier.

The first format specifier, :10, specifies that the name variable should be left-aligned within a field that is 10 characters wide. If the value of name is less than 10 characters long, the field will be padded with spaces to the right.

The second format specifier, :5, specifies that the age variable should be right-aligned within a field that is 5 characters wide. If the value of age is less than 5 characters long, the field will be padded with spaces to the left.

Format specifiers can be used to control many aspects of the formatting of values, including their width, alignment, precision, and type. Some common format codes include:

d for decimal integers
f for floating-point numbers
s for strings
e for scientific notation with a lowercase "e"
E for scientific notation with an uppercase "E"

The exact syntax of format specifiers depends on the type of value being formatted and the desired formatting options. You can find more information on format specifiers in the Python documentation.