LM Working with Strings and Simple Operators

What are strings?

Strings are sequences of characters, used to store and work with text data in Python. You can think of them as ordered collections of letters, digits, symbols, or whitespace.

Strings in Python are immutable, which means that once a string is created, it cannot be changed. Instead, any “modifications” create a new string. This property ensures safety and consistency when working with text.

Strings are also sequential data types, so you can iterate over them character by character, slice them, and perform many common sequence operations.

Examples

text = "Hello, world!"

# Accessing individual characters
first_letter = text[0]  # "H"

# Slicing
greeting = text[0:5]    # "Hello"

# Iterating over a string
for char in text:
    print(char)

# String methods
print(text.upper())     # "HELLO, WORLD!"
print(text.lower())     # "hello, world!"
print(text.replace("world", "Python"))  # "Hello, Python!"

Simple operators

You also reviewed basic operators, including:

  • Arithmetic operators (e.g., +, -, *, /)
  • Comparison operators (e.g., ==, !=, <, >)
  • Logical operators (e.g., and, or, not)

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