Operators and Expressions

Operators are the symbols that perform operations on variables and values. In Python, these are very similar to C, but with a few extra "superpowers" that make math and logic much simpler.

1. Categories of Operators

Category. Operators. Description

Arithmetic+, -, *, /, //, %, **Standard math + Floor division and Exponentiation.

Comparison==, !=, >, <, >=, <=Returns True or False.

Logicaland, or, notUsed to combine conditional statements.

Assignment=, +=, -=, *=, /=Assigns values to variables.

Membershipin, not inChecks if a value exists in a sequence (like a list).

2. Special Python Operators

Unlike C, Python includes a few specific operators for common tasks:

• Floor Division (//): Divides and rounds down to the nearest whole number.

• Exponentiation (**): Calculates power (e.g., $2^{3}$ is written as 2 ** 3).

• Logical Words: Python uses the actual words and, or, and not instead of symbols like &&, ||, and !.

# Arithmetic
print(10 / 3)   # Normal division: 3.3333...
print(10 // 3)  # Floor division: 3
print(2 ** 3)   # Exponent (2 cubed): 8

# Logical Operators
age = 20
has_license = True

if age >= 18 and has_license:
    print("You can drive!")

# Membership Operators
fruits = ["apple", "banana", "cherry"]
print("apple" in fruits)     # True
print("orange" not in fruits) # True

3. Expressions and Precedence

An expression is a combination of values and operators that evaluates to a single value. Python follows the PEMDAS rule (Parentheses, Exponents, Multiplication/Division, Addition/Subtraction).

result = 10 + 5 * 2 ** 2  # 5 * 4 = 20, then + 10 = 30
print(result)