String & String Methods in Python

In this video, we will learn about strings and string methods in Python to work with and manipulate text data. What is a String? A string is a sequence of characters enclosed in single (') or double (") quotes. name = "Alice" greeting = 'Hello' Multiline Strings Use triple quotes (''' or """) for multiline text. message = """This is a multiline string.""" String Indexing and Slicing Indexing starts at 0. text = "Python" text[0] # 'P' text[-1] # 'n' (last character) text[0:2] # 'Py' text[:3] # 'Pyt' text[3:] # 'hon' String Immutability Strings cannot be changed after creation. text[0] = 'J' # Error Common String Methods Method Description str.lower() Converts to lowercase str.upper() Converts to uppercase str.strip() Removes leading/trailing spaces str.replace(old, new) Replaces substring str.split(sep) Splits string into a list str.join(list) Joins list into string str.find(sub) Returns index of first occurrence str.count(sub) Counts occurrences of substring str.startswith(prefix) Checks if string starts with value str.endswith(suffix) Checks if string ends with value str.isdigit() Checks if all chars are digits str.isalpha() Checks if all chars are letters str.isalnum() Checks if all chars are letters/digits Examples "hello".upper() # 'HELLO' " Hello ".strip() # 'Hello' "hello world".split() # ['hello', 'world'] "-".join(["2025", "04", "14"]) # '2025-04-14' "python".find("th") # 2 String Formatting (f-strings) name = "Alice" age = 30 f"Hello, {name}. You are {age} years old." # 'Hello, Alice. You are 30 years old.'