String Manipulation & Formatting

Strings as Sequences

In Python, a string is just a sequence of characters. Because it's a sequence, you can extract individual characters using their position (index), starting from 0.

word = "Python"
print(word[0])  # Prints 'P'
print(word[-1]) # Prints 'n' (negative index counts from the end)

Slicing Strings

You can carve out chunks of a string using the slicing syntax: [start:stop:step].

text = "Hello World"
print(text[0:5])  # Prints 'Hello'
print(text[::-1]) # A neat trick to reverse a string!

Essential String Methods

Strings come with built-in superpowers (methods) that let you modify them on the fly:

• text.upper() / text.lower(): Changes casing.
• text.strip(): Removes accidental whitespace from the start and end.
• text.replace("old", "new"): Swaps out words or characters.
• text.split(","): Chops the string into a list based on a separator.

F-Strings: The Modern Way to Format

Formatting text used to be messy. Python 3.6 introduced f-strings, which let you inject variables directly into strings by wrapping them in curly braces.

name = "Sarah"
score = 95
print(f"Great job {name}, you scored {score} points!")