String Operations and Indexing

A sequence of characters enclosed within quotes (single, double, or triple).

Each character in a string has a unique index (position). Positive indices start from 0 for the first character and increase to the right. Negative indices start from -1 for the last character and decrease to the left.

You can retrieve specific characters or substrings using the slicing notation [start:end:step] with these indices.

Strings in Python are immutable, meaning they cannot be directly modified once created.

You can use escape sequences like \n for a new line, \t for a tab, \" for a double quote, and \' for a single quote to represent special characters within a string.

You can perform various operations on strings, including addition and multiplication. String multiplication concatenates a string multiple times, while string addition joins strings together.

In string indexing, [start:end:step] selects characters from the string. start is the index of the first character, end is the index of the last character (not included), and step defines the increment between characters.

In Python, you cannot modify characters directly within a string as it is immutable. You can, however, create a completely new string by concatenating the desired changes using operators or string methods.

The isspace() function checks whether all characters in a string are whitespace characters (spaces, tabs, newlines). It returns True if all characters are whitespace, and False otherwise.

The lstrip() function removes leading whitespace characters from the left side of a string. It returns a new string with the leading whitespace removed.

The rstrip() function removes trailing whitespace characters from the right side of a string. It returns a new string with the trailing whitespace removed.

The strip() function removes both leading and trailing whitespace characters from a string. It returns a new string with the whitespace removed from both ends.

The strip() function can remove characters other than whitespace by specifying a string argument to the function. The characters in the argument string will be removed from the beginning and end of the string.

A sequence of characters. Examples include "hello" or "123"

Counts how many times a substring appears within a string

Finds the index of the first occurrence of a substring within a string. Returns -1 if not found.

Similar to find(), but raises an exception if the substring is not found.

Checks if a string starts with a specified substring. Returns True or False.

Checks if a string ends with a specified substring. Returns True or False.

Checks if a string contains only alphanumeric characters (letters and numbers). Returns True or False.

Checks if a string is a valid Python identifier. Avoids keywords and starts with a letter or underscore. Returns True or False

This method checks if every character in a string is a letter (a-z, A-Z) and returns True if it is, otherwise it returns False.

A function that accepts a string as input and returns True if the string contains only digits (0-9) and False otherwise.

This string method checks if all characters in a string are lowercase and returns True if they are, otherwise it returns False.

This Python string method returns True if all characters in a string are uppercase and False otherwise.

A function that returns the number of occurrences of a substring within a string.

Determines if a string begins with a specified substring. Returns True if it does, False otherwise.

Determines if a string ends with a specified substring. Returns True if it does, False otherwise.

Examines a string to see if it contains only alphanumeric characters (letters and numbers). Returns True if so, False otherwise.

The split() method breaks a string into a list of substrings based on a specified separator. If no separator is provided, it splits at whitespace.

The ord() function converts a single character to its corresponding ASCII or Unicode numerical value. This value represents the position of the character within the ASCII/Unicode table.

The chr() function converts an integer value representing an ASCII or Unicode code point back into its corresponding character. It finds the character associated with a specific code.

This program takes a string as input and counts the number of spaces present in it.

The code takes a string as input and converts it to toggle case, switching uppercase characters to lowercase and vice versa.

This program takes a string as input and replaces all spaces within the string with hyphens.

This code takes a string as input and generates a new string without any capitalized vowels.