Python Operators Complete Guide

# Arithmetic operators
result = 10 + 5    # Addition
result = 10 - 5    # Subtraction
result = 10 * 5    # Multiplication
result = 10 / 3    # Division (returns float)

# Comparison operators
is_equal = (10 == 5)      # Equal to
is_greater = (10 > 5)     # Greater than
is_less = (10 < 5)        # Less than

# Logical operators
result = (10 > 5) and (3 < 7)  # AND operator
result = (10 > 5) or (3 > 7)   # OR operator
result = not (10 > 5)          # NOT operator

a = 15
b = 4

print(a + b)          # 19
print(a - b)          # 11
print(a * b)          # 60
print(a / b)          # 3.75 (always float)
print(a // b)         # 3
print(-15 // 4)       # -4 (rounds down)
print(a % b)          # 3
print(a ** b)         # 50625
print(2 ** 10)        # 1024
print(9 ** 0.5)       # 3.0

# Tricky points
print(10 / 2)         # 5.0, not 5
print(2 ** 3 ** 2)    # 512 (right-associative)
print((2 ** 3) ** 2)  # 64
print(-10 % 3)        # 2 (modulus sign follows divisor)

# Practical usage
hours = 25
print(hours % 12)     # 1
temperature_c = 30
print((temperature_c * 9/5) + 32)  # 86.0

x = 10
y = 20

print(x == y)   # False
print(x != y)   # True
print(x > y)    # False
print(x < y)    # True
print(x >= 10)  # True
print(x <= 10)  # True

# Chaining
age = 25
print(18 <= age <= 60)   # True
print(10 < 20 < 30)      # True
print(5 > 3 < 10)        # True

# Tricky points
print(5 == 5.0)      # True
print(True == 1)     # True
print(False == 0)    # True
print(5 == '5')      # False
# print(5 > '5')     # TypeError in Python 3

print(True and False)  # False
print(True or False)   # True
print(not True)        # False

age = 25
has_license = True
print(age >= 18 and has_license)  # True

def expensive_check():
    print("Checking...")
    return True

print(True or expensive_check())   # True, function not called
print(False and expensive_check()) # False, function not called

# Logical operators return values, not only booleans
print(0 or 5)   # 5
print(5 and 10) # 10
print(0 and 5)  # 0

x = 10
x += 5
x *= 2
x //= 3
print(x)

# Walrus operator (Python 3.8+)
if (n := len([1, 2, 3])) > 2:
    print(f"Length = {n}")

# Elegant swap
a, b = 5, 10
a, b = b, a
print(a, b)  # 10 5

# Tricky mutable assignment
p = q = [1, 2, 3]
p.append(4)
print(q)  # [1, 2, 3, 4] (same object)

a, b = 10, 6
print(a & b)   # 2
print(a | b)   # 14
print(a ^ b)   # 12
print(~a)      # -11  (~x = -x - 1)
print(a << 1)  # 20
print(a >> 1)  # 5

# Practical even/odd check
def is_even(n):
    return (n & 1) == 0

print(is_even(4))  # True
print(is_even(5))  # False

a = [1, 2, 3]
b = [1, 2, 3]
c = a

print(a == b)   # True (same values)
print(a is b)   # False (different objects)
print(a is c)   # True  (same object)

value = None
print(value is None)  # Best practice

fruits = ['apple', 'banana', 'orange']
print('apple' in fruits)      # True
print('grape' not in fruits)  # True

text = "Hello World"
print('Hello' in text)  # True
print('hello' in text)  # False (case-sensitive)

d = {'a': 1, 'b': 2}
print('a' in d)  # True (checks keys)
print(1 in d)    # False (not value)

# Operator Precedence Examples
# PEMDAS: Parentheses, Exponents, Multiplication/Division, Addition/Subtraction

result1 = 5 + 3 * 2   # Multiplication before addition
print(f"5 + 3 * 2 = {result1}")  # 11, not 16

result2 = (5 + 3) * 2 # Parentheses change precedence
print(f"(5 + 3) * 2 = {result2}")  # 16

result3 = 2 ** 3 * 2  # Exponentiation before multiplication
print(f"2 ** 3 * 2 = {result3}")   # 16 (8 * 2)

result4 = 2 * 3 ** 2  # Exponentiation before multiplication
print(f"2 * 3 ** 2 = {result4}")   # 18 (2 * 9)

# Complex expression
result5 = 10 + 20 * 3 / 2 - 5 % 3
print(f"10 + 20 * 3 / 2 - 5 % 3 = {result5}")
# Steps: 20*3=60, 60/2=30, 5%3=2, 10+30=40, 40-2=38