Subscript Operator

In Python, the subscript operator (square brackets []) is used to access individual characters or substrings within a string.

Accessing Individual Characters

You can access a specific character in a string by providing its index within square brackets. Indexing starts at 0 for the first character.

Python

my_string = "Hello, world!"

first_character = my_string[0]  # Output: 'H'

Slicing Strings

To extract a substring, you can use slicing with the subscript operator. The syntax is string[start:end:step]:

·         start: The starting index (inclusive).

·         end: The ending index (exclusive).

·         step: The step size (default is 1).

Python

my_string = "Hello, world!"

substring = my_string[2:5]  # Output: 'llo'

Negative Indexing

You can use negative indices to access characters from the end of the string:

Python

my_string = "Hello, world!"

last_character = my_string[-1]  # Output: '!'

Key Points

·         Strings are immutable, meaning you cannot change individual characters using the subscript operator.

·         The index must be within the valid range of the string length.

·         Slicing creates a new string without modifying the original.

By understanding the string subscript operator, you can effectively manipulate and extract information from strings in your Python code.